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: releng/11.1/sys/net80211/ieee80211_scan_sta.c 300232 2016-05-19 21:08:33Z avos $");
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/endian.h>
38 #include <sys/malloc.h>
39 #include <sys/module.h>
40
41 #include <sys/socket.h>
42
43 #include <net/if.h>
44 #include <net/if_var.h>
45 #include <net/if_media.h>
46 #include <net/ethernet.h>
47
48 #include <net80211/ieee80211_var.h>
49 #include <net80211/ieee80211_input.h>
50 #include <net80211/ieee80211_regdomain.h>
51 #ifdef IEEE80211_SUPPORT_TDMA
52 #include <net80211/ieee80211_tdma.h>
53 #endif
54 #ifdef IEEE80211_SUPPORT_MESH
55 #include <net80211/ieee80211_mesh.h>
56 #endif
57 #include <net80211/ieee80211_ratectl.h>
58
59 #include <net/bpf.h>
60
61 /*
62 * Parameters for managing cache entries:
63 *
64 * o a station with STA_FAILS_MAX failures is not considered
65 * when picking a candidate
66 * o a station that hasn't had an update in STA_PURGE_SCANS
67 * (background) scans is discarded
68 * o after STA_FAILS_AGE seconds we clear the failure count
69 */
70 #define STA_FAILS_MAX 2 /* assoc failures before ignored */
71 #define STA_FAILS_AGE (2*60) /* time before clearing fails (secs) */
72 #define STA_PURGE_SCANS 2 /* age for purging entries (scans) */
73
74 /* XXX tunable */
75 #define STA_RSSI_MIN 8 /* min acceptable rssi */
76 #define STA_RSSI_MAX 40 /* max rssi for comparison */
77
78 struct sta_entry {
79 struct ieee80211_scan_entry base;
80 TAILQ_ENTRY(sta_entry) se_list;
81 LIST_ENTRY(sta_entry) se_hash;
82 uint8_t se_fails; /* failure to associate count */
83 uint8_t se_seen; /* seen during current scan */
84 uint8_t se_notseen; /* not seen in previous scans */
85 uint8_t se_flags;
86 #define STA_DEMOTE11B 0x01 /* match w/ demoted 11b chan */
87 uint32_t se_avgrssi; /* LPF rssi state */
88 unsigned long se_lastupdate; /* time of last update */
89 unsigned long se_lastfail; /* time of last failure */
90 unsigned long se_lastassoc; /* time of last association */
91 u_int se_scangen; /* iterator scan gen# */
92 u_int se_countrygen; /* gen# of last cc notify */
93 };
94
95 #define STA_HASHSIZE 32
96 /* simple hash is enough for variation of macaddr */
97 #define STA_HASH(addr) \
98 (((const uint8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % STA_HASHSIZE)
99
100 #define MAX_IEEE_CHAN 256 /* max acceptable IEEE chan # */
101 CTASSERT(MAX_IEEE_CHAN >= 256);
102
103 struct sta_table {
104 ieee80211_scan_table_lock_t st_lock; /* on scan table */
105 TAILQ_HEAD(, sta_entry) st_entry; /* all entries */
106 LIST_HEAD(, sta_entry) st_hash[STA_HASHSIZE];
107 ieee80211_scan_iter_lock_t st_scanlock; /* on st_scaniter */
108 u_int st_scaniter; /* gen# for iterator */
109 u_int st_scangen; /* scan generation # */
110 int st_newscan;
111 /* ap-related state */
112 int st_maxrssi[MAX_IEEE_CHAN];
113 };
114
115 static void sta_flush_table(struct sta_table *);
116 /*
117 * match_bss returns a bitmask describing if an entry is suitable
118 * for use. If non-zero the entry was deemed not suitable and it's
119 * contents explains why. The following flags are or'd to to this
120 * mask and can be used to figure out why the entry was rejected.
121 */
122 #define MATCH_CHANNEL 0x00001 /* channel mismatch */
123 #define MATCH_CAPINFO 0x00002 /* capabilities mismatch, e.g. no ess */
124 #define MATCH_PRIVACY 0x00004 /* privacy mismatch */
125 #define MATCH_RATE 0x00008 /* rate set mismatch */
126 #define MATCH_SSID 0x00010 /* ssid mismatch */
127 #define MATCH_BSSID 0x00020 /* bssid mismatch */
128 #define MATCH_FAILS 0x00040 /* too many failed auth attempts */
129 #define MATCH_NOTSEEN 0x00080 /* not seen in recent scans */
130 #define MATCH_RSSI 0x00100 /* rssi deemed too low to use */
131 #define MATCH_CC 0x00200 /* country code mismatch */
132 #ifdef IEEE80211_SUPPORT_TDMA
133 #define MATCH_TDMA_NOIE 0x00400 /* no TDMA ie */
134 #define MATCH_TDMA_NOTMASTER 0x00800 /* not TDMA master */
135 #define MATCH_TDMA_NOSLOT 0x01000 /* all TDMA slots occupied */
136 #define MATCH_TDMA_LOCAL 0x02000 /* local address */
137 #define MATCH_TDMA_VERSION 0x04000 /* protocol version mismatch */
138 #endif
139 #define MATCH_MESH_NOID 0x10000 /* no MESHID ie */
140 #define MATCH_MESHID 0x20000 /* meshid mismatch */
141 static int match_bss(struct ieee80211vap *,
142 const struct ieee80211_scan_state *, struct sta_entry *, int);
143 static void adhoc_age(struct ieee80211_scan_state *);
144
145 static __inline int
146 isocmp(const uint8_t cc1[], const uint8_t cc2[])
147 {
148 return (cc1[0] == cc2[0] && cc1[1] == cc2[1]);
149 }
150
151 /* number of references from net80211 layer */
152 static int nrefs = 0;
153 /*
154 * Module glue.
155 */
156 IEEE80211_SCANNER_MODULE(sta, 1);
157
158 /*
159 * Attach prior to any scanning work.
160 */
161 static int
162 sta_attach(struct ieee80211_scan_state *ss)
163 {
164 struct sta_table *st;
165
166 st = (struct sta_table *) IEEE80211_MALLOC(sizeof(struct sta_table),
167 M_80211_SCAN,
168 IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
169 if (st == NULL)
170 return 0;
171 IEEE80211_SCAN_TABLE_LOCK_INIT(st, "scantable");
172 IEEE80211_SCAN_ITER_LOCK_INIT(st, "scangen");
173 TAILQ_INIT(&st->st_entry);
174 ss->ss_priv = st;
175 nrefs++; /* NB: we assume caller locking */
176 return 1;
177 }
178
179 /*
180 * Cleanup any private state.
181 */
182 static int
183 sta_detach(struct ieee80211_scan_state *ss)
184 {
185 struct sta_table *st = ss->ss_priv;
186
187 if (st != NULL) {
188 sta_flush_table(st);
189 IEEE80211_SCAN_TABLE_LOCK_DESTROY(st);
190 IEEE80211_SCAN_ITER_LOCK_DESTROY(st);
191 IEEE80211_FREE(st, M_80211_SCAN);
192 KASSERT(nrefs > 0, ("imbalanced attach/detach"));
193 nrefs--; /* NB: we assume caller locking */
194 }
195 return 1;
196 }
197
198 /*
199 * Flush all per-scan state.
200 */
201 static int
202 sta_flush(struct ieee80211_scan_state *ss)
203 {
204 struct sta_table *st = ss->ss_priv;
205
206 IEEE80211_SCAN_TABLE_LOCK(st);
207 sta_flush_table(st);
208 IEEE80211_SCAN_TABLE_UNLOCK(st);
209 ss->ss_last = 0;
210 return 0;
211 }
212
213 /*
214 * Flush all entries in the scan cache.
215 */
216 static void
217 sta_flush_table(struct sta_table *st)
218 {
219 struct sta_entry *se, *next;
220
221 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) {
222 TAILQ_REMOVE(&st->st_entry, se, se_list);
223 LIST_REMOVE(se, se_hash);
224 ieee80211_ies_cleanup(&se->base.se_ies);
225 IEEE80211_FREE(se, M_80211_SCAN);
226 }
227 memset(st->st_maxrssi, 0, sizeof(st->st_maxrssi));
228 }
229
230 /*
231 * Process a beacon or probe response frame; create an
232 * entry in the scan cache or update any previous entry.
233 */
234 static int
235 sta_add(struct ieee80211_scan_state *ss,
236 struct ieee80211_channel *curchan,
237 const struct ieee80211_scanparams *sp,
238 const struct ieee80211_frame *wh,
239 int subtype, int rssi, int noise)
240 {
241 #define ISPROBE(_st) ((_st) == IEEE80211_FC0_SUBTYPE_PROBE_RESP)
242 #define PICK1ST(_ss) \
243 ((ss->ss_flags & (IEEE80211_SCAN_PICK1ST | IEEE80211_SCAN_GOTPICK)) == \
244 IEEE80211_SCAN_PICK1ST)
245 struct sta_table *st = ss->ss_priv;
246 const uint8_t *macaddr = wh->i_addr2;
247 struct ieee80211vap *vap = ss->ss_vap;
248 struct ieee80211com *ic = vap->iv_ic;
249 struct ieee80211_channel *c;
250 struct sta_entry *se;
251 struct ieee80211_scan_entry *ise;
252 int hash;
253
254 hash = STA_HASH(macaddr);
255
256 IEEE80211_SCAN_TABLE_LOCK(st);
257 LIST_FOREACH(se, &st->st_hash[hash], se_hash)
258 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr))
259 goto found;
260 se = (struct sta_entry *) IEEE80211_MALLOC(sizeof(struct sta_entry),
261 M_80211_SCAN, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
262 if (se == NULL) {
263 IEEE80211_SCAN_TABLE_UNLOCK(st);
264 return 0;
265 }
266 se->se_scangen = st->st_scaniter-1;
267 se->se_avgrssi = IEEE80211_RSSI_DUMMY_MARKER;
268 IEEE80211_ADDR_COPY(se->base.se_macaddr, macaddr);
269 TAILQ_INSERT_TAIL(&st->st_entry, se, se_list);
270 LIST_INSERT_HEAD(&st->st_hash[hash], se, se_hash);
271 found:
272 ise = &se->base;
273 /* XXX ap beaconing multiple ssid w/ same bssid */
274 if (sp->ssid[1] != 0 &&
275 (ISPROBE(subtype) || ise->se_ssid[1] == 0))
276 memcpy(ise->se_ssid, sp->ssid, 2+sp->ssid[1]);
277 KASSERT(sp->rates[1] <= IEEE80211_RATE_MAXSIZE,
278 ("rate set too large: %u", sp->rates[1]));
279 memcpy(ise->se_rates, sp->rates, 2+sp->rates[1]);
280 if (sp->xrates != NULL) {
281 /* XXX validate xrates[1] */
282 KASSERT(sp->xrates[1] <= IEEE80211_RATE_MAXSIZE,
283 ("xrate set too large: %u", sp->xrates[1]));
284 memcpy(ise->se_xrates, sp->xrates, 2+sp->xrates[1]);
285 } else
286 ise->se_xrates[1] = 0;
287 IEEE80211_ADDR_COPY(ise->se_bssid, wh->i_addr3);
288 if ((sp->status & IEEE80211_BPARSE_OFFCHAN) == 0) {
289 /*
290 * Record rssi data using extended precision LPF filter.
291 *
292 * NB: use only on-channel data to insure we get a good
293 * estimate of the signal we'll see when associated.
294 */
295 IEEE80211_RSSI_LPF(se->se_avgrssi, rssi);
296 ise->se_rssi = IEEE80211_RSSI_GET(se->se_avgrssi);
297 ise->se_noise = noise;
298 }
299 memcpy(ise->se_tstamp.data, sp->tstamp, sizeof(ise->se_tstamp));
300 ise->se_intval = sp->bintval;
301 ise->se_capinfo = sp->capinfo;
302 #ifdef IEEE80211_SUPPORT_MESH
303 if (sp->meshid != NULL && sp->meshid[1] != 0)
304 memcpy(ise->se_meshid, sp->meshid, 2+sp->meshid[1]);
305 #endif
306 /*
307 * Beware of overriding se_chan for frames seen
308 * off-channel; this can cause us to attempt an
309 * association on the wrong channel.
310 */
311 if (sp->status & IEEE80211_BPARSE_OFFCHAN) {
312 /*
313 * Off-channel, locate the home/bss channel for the sta
314 * using the value broadcast in the DSPARMS ie. We know
315 * sp->chan has this value because it's used to calculate
316 * IEEE80211_BPARSE_OFFCHAN.
317 */
318 c = ieee80211_find_channel_byieee(ic, sp->chan,
319 curchan->ic_flags);
320 if (c != NULL) {
321 ise->se_chan = c;
322 } else if (ise->se_chan == NULL) {
323 /* should not happen, pick something */
324 ise->se_chan = curchan;
325 }
326 } else
327 ise->se_chan = curchan;
328 if (IEEE80211_IS_CHAN_HT(ise->se_chan) && sp->htcap == NULL) {
329 /* Demote legacy networks to a non-HT channel. */
330 c = ieee80211_find_channel(ic, ise->se_chan->ic_freq,
331 ise->se_chan->ic_flags & ~IEEE80211_CHAN_HT);
332 KASSERT(c != NULL,
333 ("no legacy channel %u", ise->se_chan->ic_ieee));
334 ise->se_chan = c;
335 }
336 ise->se_fhdwell = sp->fhdwell;
337 ise->se_fhindex = sp->fhindex;
338 ise->se_erp = sp->erp;
339 ise->se_timoff = sp->timoff;
340 if (sp->tim != NULL) {
341 const struct ieee80211_tim_ie *tim =
342 (const struct ieee80211_tim_ie *) sp->tim;
343 ise->se_dtimperiod = tim->tim_period;
344 }
345 if (sp->country != NULL) {
346 const struct ieee80211_country_ie *cie =
347 (const struct ieee80211_country_ie *) sp->country;
348 /*
349 * If 11d is enabled and we're attempting to join a bss
350 * that advertises it's country code then compare our
351 * current settings to what we fetched from the country ie.
352 * If our country code is unspecified or different then
353 * dispatch an event to user space that identifies the
354 * country code so our regdomain config can be changed.
355 */
356 /* XXX only for STA mode? */
357 if ((IEEE80211_IS_CHAN_11D(ise->se_chan) ||
358 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) &&
359 (ic->ic_regdomain.country == CTRY_DEFAULT ||
360 !isocmp(cie->cc, ic->ic_regdomain.isocc))) {
361 /* only issue one notify event per scan */
362 if (se->se_countrygen != st->st_scangen) {
363 ieee80211_notify_country(vap, ise->se_bssid,
364 cie->cc);
365 se->se_countrygen = st->st_scangen;
366 }
367 }
368 ise->se_cc[0] = cie->cc[0];
369 ise->se_cc[1] = cie->cc[1];
370 }
371 /* NB: no need to setup ie ptrs; they are not (currently) used */
372 (void) ieee80211_ies_init(&ise->se_ies, sp->ies, sp->ies_len);
373
374 /* clear failure count after STA_FAIL_AGE passes */
375 if (se->se_fails && (ticks - se->se_lastfail) > STA_FAILS_AGE*hz) {
376 se->se_fails = 0;
377 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, macaddr,
378 "%s: fails %u", __func__, se->se_fails);
379 }
380
381 se->se_lastupdate = ticks; /* update time */
382 se->se_seen = 1;
383 se->se_notseen = 0;
384
385 KASSERT(sizeof(sp->bchan) == 1, ("bchan size"));
386 if (rssi > st->st_maxrssi[sp->bchan])
387 st->st_maxrssi[sp->bchan] = rssi;
388
389 IEEE80211_SCAN_TABLE_UNLOCK(st);
390
391 /*
392 * If looking for a quick choice and nothing's
393 * been found check here.
394 */
395 if (PICK1ST(ss) && match_bss(vap, ss, se, IEEE80211_MSG_SCAN) == 0)
396 ss->ss_flags |= IEEE80211_SCAN_GOTPICK;
397
398 return 1;
399 #undef PICK1ST
400 #undef ISPROBE
401 }
402
403 /*
404 * Check if a channel is excluded by user request.
405 */
406 static int
407 isexcluded(struct ieee80211vap *vap, const struct ieee80211_channel *c)
408 {
409 return (isclr(vap->iv_ic->ic_chan_active, c->ic_ieee) ||
410 (vap->iv_des_chan != IEEE80211_CHAN_ANYC &&
411 c->ic_freq != vap->iv_des_chan->ic_freq));
412 }
413
414 static struct ieee80211_channel *
415 find11gchannel(struct ieee80211com *ic, int i, int freq)
416 {
417 struct ieee80211_channel *c;
418 int j;
419
420 /*
421 * The normal ordering in the channel list is b channel
422 * immediately followed by g so optimize the search for
423 * this. We'll still do a full search just in case.
424 */
425 for (j = i+1; j < ic->ic_nchans; j++) {
426 c = &ic->ic_channels[j];
427 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c))
428 return c;
429 }
430 for (j = 0; j < i; j++) {
431 c = &ic->ic_channels[j];
432 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c))
433 return c;
434 }
435 return NULL;
436 }
437
438 static const u_int chanflags[IEEE80211_MODE_MAX] = {
439 [IEEE80211_MODE_AUTO] = IEEE80211_CHAN_B,
440 [IEEE80211_MODE_11A] = IEEE80211_CHAN_A,
441 [IEEE80211_MODE_11B] = IEEE80211_CHAN_B,
442 [IEEE80211_MODE_11G] = IEEE80211_CHAN_G,
443 [IEEE80211_MODE_FH] = IEEE80211_CHAN_FHSS,
444 /* check base channel */
445 [IEEE80211_MODE_TURBO_A] = IEEE80211_CHAN_A,
446 [IEEE80211_MODE_TURBO_G] = IEEE80211_CHAN_G,
447 [IEEE80211_MODE_STURBO_A] = IEEE80211_CHAN_ST,
448 [IEEE80211_MODE_HALF] = IEEE80211_CHAN_HALF,
449 [IEEE80211_MODE_QUARTER] = IEEE80211_CHAN_QUARTER,
450 /* check legacy */
451 [IEEE80211_MODE_11NA] = IEEE80211_CHAN_A,
452 [IEEE80211_MODE_11NG] = IEEE80211_CHAN_G,
453 };
454
455 static void
456 add_channels(struct ieee80211vap *vap,
457 struct ieee80211_scan_state *ss,
458 enum ieee80211_phymode mode, const uint16_t freq[], int nfreq)
459 {
460 struct ieee80211com *ic = vap->iv_ic;
461 struct ieee80211_channel *c, *cg;
462 u_int modeflags;
463 int i;
464
465 KASSERT(mode < nitems(chanflags), ("Unexpected mode %u", mode));
466 modeflags = chanflags[mode];
467 for (i = 0; i < nfreq; i++) {
468 if (ss->ss_last >= IEEE80211_SCAN_MAX)
469 break;
470
471 c = ieee80211_find_channel(ic, freq[i], modeflags);
472 if (c == NULL || isexcluded(vap, c))
473 continue;
474 if (mode == IEEE80211_MODE_AUTO) {
475 /*
476 * XXX special-case 11b/g channels so we select
477 * the g channel if both are present.
478 */
479 if (IEEE80211_IS_CHAN_B(c) &&
480 (cg = find11gchannel(ic, i, c->ic_freq)) != NULL)
481 c = cg;
482 }
483 ss->ss_chans[ss->ss_last++] = c;
484 }
485 }
486
487 struct scanlist {
488 uint16_t mode;
489 uint16_t count;
490 const uint16_t *list;
491 };
492
493 static int
494 checktable(const struct scanlist *scan, const struct ieee80211_channel *c)
495 {
496 int i;
497
498 for (; scan->list != NULL; scan++) {
499 for (i = 0; i < scan->count; i++)
500 if (scan->list[i] == c->ic_freq)
501 return 1;
502 }
503 return 0;
504 }
505
506 static int
507 onscanlist(const struct ieee80211_scan_state *ss,
508 const struct ieee80211_channel *c)
509 {
510 int i;
511
512 for (i = 0; i < ss->ss_last; i++)
513 if (ss->ss_chans[i] == c)
514 return 1;
515 return 0;
516 }
517
518 static void
519 sweepchannels(struct ieee80211_scan_state *ss, struct ieee80211vap *vap,
520 const struct scanlist table[])
521 {
522 struct ieee80211com *ic = vap->iv_ic;
523 struct ieee80211_channel *c;
524 int i;
525
526 for (i = 0; i < ic->ic_nchans; i++) {
527 if (ss->ss_last >= IEEE80211_SCAN_MAX)
528 break;
529
530 c = &ic->ic_channels[i];
531 /*
532 * Ignore dynamic turbo channels; we scan them
533 * in normal mode (i.e. not boosted). Likewise
534 * for HT channels, they get scanned using
535 * legacy rates.
536 */
537 if (IEEE80211_IS_CHAN_DTURBO(c) || IEEE80211_IS_CHAN_HT(c))
538 continue;
539
540 /*
541 * If a desired mode was specified, scan only
542 * channels that satisfy that constraint.
543 */
544 if (vap->iv_des_mode != IEEE80211_MODE_AUTO &&
545 vap->iv_des_mode != ieee80211_chan2mode(c))
546 continue;
547
548 /*
549 * Skip channels excluded by user request.
550 */
551 if (isexcluded(vap, c))
552 continue;
553
554 /*
555 * Add the channel unless it is listed in the
556 * fixed scan order tables. This insures we
557 * don't sweep back in channels we filtered out
558 * above.
559 */
560 if (checktable(table, c))
561 continue;
562
563 /* Add channel to scanning list. */
564 ss->ss_chans[ss->ss_last++] = c;
565 }
566 /*
567 * Explicitly add any desired channel if:
568 * - not already on the scan list
569 * - allowed by any desired mode constraint
570 * - there is space in the scan list
571 * This allows the channel to be used when the filtering
572 * mechanisms would otherwise elide it (e.g HT, turbo).
573 */
574 c = vap->iv_des_chan;
575 if (c != IEEE80211_CHAN_ANYC &&
576 !onscanlist(ss, c) &&
577 (vap->iv_des_mode == IEEE80211_MODE_AUTO ||
578 vap->iv_des_mode == ieee80211_chan2mode(c)) &&
579 ss->ss_last < IEEE80211_SCAN_MAX)
580 ss->ss_chans[ss->ss_last++] = c;
581 }
582
583 static void
584 makescanlist(struct ieee80211_scan_state *ss, struct ieee80211vap *vap,
585 const struct scanlist table[])
586 {
587 const struct scanlist *scan;
588 enum ieee80211_phymode mode;
589
590 ss->ss_last = 0;
591 /*
592 * Use the table of ordered channels to construct the list
593 * of channels for scanning. Any channels in the ordered
594 * list not in the master list will be discarded.
595 */
596 for (scan = table; scan->list != NULL; scan++) {
597 mode = scan->mode;
598 if (vap->iv_des_mode != IEEE80211_MODE_AUTO) {
599 /*
600 * If a desired mode was specified, scan only
601 * channels that satisfy that constraint.
602 */
603 if (vap->iv_des_mode != mode) {
604 /*
605 * The scan table marks 2.4Ghz channels as b
606 * so if the desired mode is 11g, then use
607 * the 11b channel list but upgrade the mode.
608 */
609 if (vap->iv_des_mode == IEEE80211_MODE_11G) {
610 if (mode == IEEE80211_MODE_11G) /* Skip the G check */
611 continue;
612 else if (mode == IEEE80211_MODE_11B)
613 mode = IEEE80211_MODE_11G; /* upgrade */
614 }
615 }
616 } else {
617 /*
618 * This lets add_channels upgrade an 11b channel
619 * to 11g if available.
620 */
621 if (mode == IEEE80211_MODE_11B)
622 mode = IEEE80211_MODE_AUTO;
623 }
624 #ifdef IEEE80211_F_XR
625 /* XR does not operate on turbo channels */
626 if ((vap->iv_flags & IEEE80211_F_XR) &&
627 (mode == IEEE80211_MODE_TURBO_A ||
628 mode == IEEE80211_MODE_TURBO_G ||
629 mode == IEEE80211_MODE_STURBO_A))
630 continue;
631 #endif
632 /*
633 * Add the list of the channels; any that are not
634 * in the master channel list will be discarded.
635 */
636 add_channels(vap, ss, mode, scan->list, scan->count);
637 }
638
639 /*
640 * Add the channels from the ic that are not present
641 * in the table.
642 */
643 sweepchannels(ss, vap, table);
644 }
645
646 static const uint16_t rcl1[] = /* 8 FCC channel: 52, 56, 60, 64, 36, 40, 44, 48 */
647 { 5260, 5280, 5300, 5320, 5180, 5200, 5220, 5240 };
648 static const uint16_t rcl2[] = /* 4 MKK channels: 34, 38, 42, 46 */
649 { 5170, 5190, 5210, 5230 };
650 static const uint16_t rcl3[] = /* 2.4Ghz ch: 1,6,11,7,13 */
651 { 2412, 2437, 2462, 2442, 2472 };
652 static const uint16_t rcl4[] = /* 5 FCC channel: 149, 153, 161, 165 */
653 { 5745, 5765, 5785, 5805, 5825 };
654 static const uint16_t rcl7[] = /* 11 ETSI channel: 100,104,108,112,116,120,124,128,132,136,140 */
655 { 5500, 5520, 5540, 5560, 5580, 5600, 5620, 5640, 5660, 5680, 5700 };
656 static const uint16_t rcl8[] = /* 2.4Ghz ch: 2,3,4,5,8,9,10,12 */
657 { 2417, 2422, 2427, 2432, 2447, 2452, 2457, 2467 };
658 static const uint16_t rcl9[] = /* 2.4Ghz ch: 14 */
659 { 2484 };
660 static const uint16_t rcl10[] = /* Added Korean channels 2312-2372 */
661 { 2312, 2317, 2322, 2327, 2332, 2337, 2342, 2347, 2352, 2357, 2362, 2367, 2372 };
662 static const uint16_t rcl11[] = /* Added Japan channels in 4.9/5.0 spectrum */
663 { 5040, 5060, 5080, 4920, 4940, 4960, 4980 };
664 #ifdef ATH_TURBO_SCAN
665 static const uint16_t rcl5[] = /* 3 static turbo channels */
666 { 5210, 5250, 5290 };
667 static const uint16_t rcl6[] = /* 2 static turbo channels */
668 { 5760, 5800 };
669 static const uint16_t rcl6x[] = /* 4 FCC3 turbo channels */
670 { 5540, 5580, 5620, 5660 };
671 static const uint16_t rcl12[] = /* 2.4Ghz Turbo channel 6 */
672 { 2437 };
673 static const uint16_t rcl13[] = /* dynamic Turbo channels */
674 { 5200, 5240, 5280, 5765, 5805 };
675 #endif /* ATH_TURBO_SCAN */
676
677 #define X(a) .count = sizeof(a)/sizeof(a[0]), .list = a
678
679 static const struct scanlist staScanTable[] = {
680 { IEEE80211_MODE_11B, X(rcl3) },
681 { IEEE80211_MODE_11A, X(rcl1) },
682 { IEEE80211_MODE_11A, X(rcl2) },
683 { IEEE80211_MODE_11B, X(rcl8) },
684 { IEEE80211_MODE_11B, X(rcl9) },
685 { IEEE80211_MODE_11A, X(rcl4) },
686 #ifdef ATH_TURBO_SCAN
687 { IEEE80211_MODE_STURBO_A, X(rcl5) },
688 { IEEE80211_MODE_STURBO_A, X(rcl6) },
689 { IEEE80211_MODE_TURBO_A, X(rcl6x) },
690 { IEEE80211_MODE_TURBO_A, X(rcl13) },
691 #endif /* ATH_TURBO_SCAN */
692 { IEEE80211_MODE_11A, X(rcl7) },
693 { IEEE80211_MODE_11B, X(rcl10) },
694 { IEEE80211_MODE_11A, X(rcl11) },
695 #ifdef ATH_TURBO_SCAN
696 { IEEE80211_MODE_TURBO_G, X(rcl12) },
697 #endif /* ATH_TURBO_SCAN */
698 { .list = NULL }
699 };
700
701 /*
702 * Start a station-mode scan by populating the channel list.
703 */
704 static int
705 sta_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
706 {
707 struct sta_table *st = ss->ss_priv;
708
709 makescanlist(ss, vap, staScanTable);
710
711 if (ss->ss_mindwell == 0)
712 ss->ss_mindwell = msecs_to_ticks(20); /* 20ms */
713 if (ss->ss_maxdwell == 0)
714 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
715
716 st->st_scangen++;
717 st->st_newscan = 1;
718
719 return 0;
720 }
721
722 /*
723 * Restart a scan, typically a bg scan but can
724 * also be a fg scan that came up empty.
725 */
726 static int
727 sta_restart(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
728 {
729 struct sta_table *st = ss->ss_priv;
730
731 st->st_newscan = 1;
732 return 0;
733 }
734
735 /*
736 * Cancel an ongoing scan.
737 */
738 static int
739 sta_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
740 {
741 return 0;
742 }
743
744 /*
745 * Demote any supplied 11g channel to 11b. There should
746 * always be an 11b channel but we check anyway...
747 */
748 static struct ieee80211_channel *
749 demote11b(struct ieee80211vap *vap, struct ieee80211_channel *chan)
750 {
751 struct ieee80211_channel *c;
752
753 if (IEEE80211_IS_CHAN_ANYG(chan) &&
754 vap->iv_des_mode == IEEE80211_MODE_AUTO) {
755 c = ieee80211_find_channel(vap->iv_ic, chan->ic_freq,
756 (chan->ic_flags &~ (IEEE80211_CHAN_PUREG | IEEE80211_CHAN_G)) |
757 IEEE80211_CHAN_B);
758 if (c != NULL)
759 chan = c;
760 }
761 return chan;
762 }
763
764 static int
765 maxrate(const struct ieee80211_scan_entry *se)
766 {
767 const struct ieee80211_ie_htcap *htcap =
768 (const struct ieee80211_ie_htcap *) se->se_ies.htcap_ie;
769 int rmax, r, i, txstream;
770 uint16_t caps;
771 uint8_t txparams;
772
773 rmax = 0;
774 if (htcap != NULL) {
775 /*
776 * HT station; inspect supported MCS and then adjust
777 * rate by channel width.
778 */
779 txparams = htcap->hc_mcsset[12];
780 if (txparams & 0x3) {
781 /*
782 * TX MCS parameters defined and not equal to RX,
783 * extract the number of spartial streams and
784 * map it to the highest MCS rate.
785 */
786 txstream = ((txparams & 0xc) >> 2) + 1;
787 i = txstream * 8 - 1;
788 } else
789 for (i = 31; i >= 0 && isclr(htcap->hc_mcsset, i); i--);
790 if (i >= 0) {
791 caps = le16dec(&htcap->hc_cap);
792 if ((caps & IEEE80211_HTCAP_CHWIDTH40) &&
793 (caps & IEEE80211_HTCAP_SHORTGI40))
794 rmax = ieee80211_htrates[i].ht40_rate_400ns;
795 else if (caps & IEEE80211_HTCAP_CHWIDTH40)
796 rmax = ieee80211_htrates[i].ht40_rate_800ns;
797 else if (caps & IEEE80211_HTCAP_SHORTGI20)
798 rmax = ieee80211_htrates[i].ht20_rate_400ns;
799 else
800 rmax = ieee80211_htrates[i].ht20_rate_800ns;
801 }
802 }
803 for (i = 0; i < se->se_rates[1]; i++) {
804 r = se->se_rates[2+i] & IEEE80211_RATE_VAL;
805 if (r > rmax)
806 rmax = r;
807 }
808 for (i = 0; i < se->se_xrates[1]; i++) {
809 r = se->se_xrates[2+i] & IEEE80211_RATE_VAL;
810 if (r > rmax)
811 rmax = r;
812 }
813 return rmax;
814 }
815
816 /*
817 * Compare the capabilities of two entries and decide which is
818 * more desirable (return >0 if a is considered better). Note
819 * that we assume compatibility/usability has already been checked
820 * so we don't need to (e.g. validate whether privacy is supported).
821 * Used to select the best scan candidate for association in a BSS.
822 */
823 static int
824 sta_compare(const struct sta_entry *a, const struct sta_entry *b)
825 {
826 #define PREFER(_a,_b,_what) do { \
827 if (((_a) ^ (_b)) & (_what)) \
828 return ((_a) & (_what)) ? 1 : -1; \
829 } while (0)
830 int maxa, maxb;
831 int8_t rssia, rssib;
832 int weight;
833
834 /* privacy support */
835 PREFER(a->base.se_capinfo, b->base.se_capinfo,
836 IEEE80211_CAPINFO_PRIVACY);
837
838 /* compare count of previous failures */
839 weight = b->se_fails - a->se_fails;
840 if (abs(weight) > 1)
841 return weight;
842
843 /*
844 * Compare rssi. If the two are considered equivalent
845 * then fallback to other criteria. We threshold the
846 * comparisons to avoid selecting an ap purely by rssi
847 * when both values may be good but one ap is otherwise
848 * more desirable (e.g. an 11b-only ap with stronger
849 * signal than an 11g ap).
850 */
851 rssia = MIN(a->base.se_rssi, STA_RSSI_MAX);
852 rssib = MIN(b->base.se_rssi, STA_RSSI_MAX);
853 if (abs(rssib - rssia) < 5) {
854 /* best/max rate preferred if signal level close enough XXX */
855 maxa = maxrate(&a->base);
856 maxb = maxrate(&b->base);
857 if (maxa != maxb)
858 return maxa - maxb;
859 /* XXX use freq for channel preference */
860 /* for now just prefer 5Ghz band to all other bands */
861 PREFER(IEEE80211_IS_CHAN_5GHZ(a->base.se_chan),
862 IEEE80211_IS_CHAN_5GHZ(b->base.se_chan), 1);
863 }
864 /* all things being equal, use signal level */
865 return a->base.se_rssi - b->base.se_rssi;
866 #undef PREFER
867 }
868
869 /*
870 * Check rate set suitability and return the best supported rate.
871 * XXX inspect MCS for HT
872 */
873 static int
874 check_rate(struct ieee80211vap *vap, const struct ieee80211_channel *chan,
875 const struct ieee80211_scan_entry *se)
876 {
877 const struct ieee80211_rateset *srs;
878 int i, j, nrs, r, okrate, badrate, fixedrate, ucastrate;
879 const uint8_t *rs;
880
881 okrate = badrate = 0;
882
883 srs = ieee80211_get_suprates(vap->iv_ic, chan);
884 nrs = se->se_rates[1];
885 rs = se->se_rates+2;
886 /* XXX MCS */
887 ucastrate = vap->iv_txparms[ieee80211_chan2mode(chan)].ucastrate;
888 fixedrate = IEEE80211_FIXED_RATE_NONE;
889 again:
890 for (i = 0; i < nrs; i++) {
891 r = IEEE80211_RV(rs[i]);
892 badrate = r;
893 /*
894 * Check any fixed rate is included.
895 */
896 if (r == ucastrate)
897 fixedrate = r;
898 /*
899 * Check against our supported rates.
900 */
901 for (j = 0; j < srs->rs_nrates; j++)
902 if (r == IEEE80211_RV(srs->rs_rates[j])) {
903 if (r > okrate) /* NB: track max */
904 okrate = r;
905 break;
906 }
907
908 if (j == srs->rs_nrates && (rs[i] & IEEE80211_RATE_BASIC)) {
909 /*
910 * Don't try joining a BSS, if we don't support
911 * one of its basic rates.
912 */
913 okrate = 0;
914 goto back;
915 }
916 }
917 if (rs == se->se_rates+2) {
918 /* scan xrates too; sort of an algol68-style for loop */
919 nrs = se->se_xrates[1];
920 rs = se->se_xrates+2;
921 goto again;
922 }
923
924 back:
925 if (okrate == 0 || ucastrate != fixedrate)
926 return badrate | IEEE80211_RATE_BASIC;
927 else
928 return IEEE80211_RV(okrate);
929 }
930
931 static __inline int
932 match_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
937 static int
938 match_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
951 static int
952 tdma_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 */
967 static int
968 match_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
1150 static void
1151 sta_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
1172 static void
1173 sta_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
1184 static struct sta_entry *
1185 select_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 */
1211 static int
1212 sta_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;
1244 notfound:
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 */
1275 static struct sta_entry *
1276 sta_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
1290 static void
1291 sta_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 (ieee80211_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 ieee80211_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 */
1366 static void
1367 sta_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 */
1394 static void
1395 sta_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 IEEE80211_SCAN_ITER_LOCK(st);
1403 gen = st->st_scaniter++;
1404 restart:
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 IEEE80211_SCAN_ITER_UNLOCK(st);
1419 }
1420
1421 static void
1422 sta_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
1438 static void
1439 sta_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
1457 static 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 IEEE80211_SCANNER_ALG(sta, IEEE80211_M_STA, sta_default);
1473
1474 /*
1475 * Adhoc mode-specific support.
1476 */
1477
1478 static const uint16_t adhocWorld[] = /* 36, 40, 44, 48 */
1479 { 5180, 5200, 5220, 5240 };
1480 static const uint16_t adhocFcc3[] = /* 36, 40, 44, 48 145, 149, 153, 157, 161, 165 */
1481 { 5180, 5200, 5220, 5240, 5725, 5745, 5765, 5785, 5805, 5825 };
1482 static const uint16_t adhocMkk[] = /* 34, 38, 42, 46 */
1483 { 5170, 5190, 5210, 5230 };
1484 static const uint16_t adhoc11b[] = /* 10, 11 */
1485 { 2457, 2462 };
1486
1487 static const struct scanlist adhocScanTable[] = {
1488 { IEEE80211_MODE_11B, X(adhoc11b) },
1489 { IEEE80211_MODE_11A, X(adhocWorld) },
1490 { IEEE80211_MODE_11A, X(adhocFcc3) },
1491 { IEEE80211_MODE_11B, X(adhocMkk) },
1492 { .list = NULL }
1493 };
1494 #undef X
1495
1496 /*
1497 * Start an adhoc-mode scan by populating the channel list.
1498 */
1499 static int
1500 adhoc_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1501 {
1502 struct sta_table *st = ss->ss_priv;
1503
1504 makescanlist(ss, vap, adhocScanTable);
1505
1506 if (ss->ss_mindwell == 0)
1507 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */
1508 if (ss->ss_maxdwell == 0)
1509 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
1510
1511 st->st_scangen++;
1512 st->st_newscan = 1;
1513
1514 return 0;
1515 }
1516
1517 /*
1518 * Select a channel to start an adhoc network on.
1519 * The channel list was populated with appropriate
1520 * channels so select one that looks least occupied.
1521 */
1522 static struct ieee80211_channel *
1523 adhoc_pick_channel(struct ieee80211_scan_state *ss, int flags)
1524 {
1525 struct sta_table *st = ss->ss_priv;
1526 struct sta_entry *se;
1527 struct ieee80211_channel *c, *bestchan;
1528 int i, bestrssi, maxrssi;
1529
1530 bestchan = NULL;
1531 bestrssi = -1;
1532
1533 IEEE80211_SCAN_TABLE_LOCK(st);
1534 for (i = 0; i < ss->ss_last; i++) {
1535 c = ss->ss_chans[i];
1536 /* never consider a channel with radar */
1537 if (IEEE80211_IS_CHAN_RADAR(c))
1538 continue;
1539 /* skip channels disallowed by regulatory settings */
1540 if (IEEE80211_IS_CHAN_NOADHOC(c))
1541 continue;
1542 /* check channel attributes for band compatibility */
1543 if (flags != 0 && (c->ic_flags & flags) != flags)
1544 continue;
1545 maxrssi = 0;
1546 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1547 if (se->base.se_chan != c)
1548 continue;
1549 if (se->base.se_rssi > maxrssi)
1550 maxrssi = se->base.se_rssi;
1551 }
1552 if (bestchan == NULL || maxrssi < bestrssi)
1553 bestchan = c;
1554 }
1555 IEEE80211_SCAN_TABLE_UNLOCK(st);
1556
1557 return bestchan;
1558 }
1559
1560 /*
1561 * Pick an ibss network to join or find a channel
1562 * to use to start an ibss network.
1563 */
1564 static int
1565 adhoc_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1566 {
1567 struct sta_table *st = ss->ss_priv;
1568 struct sta_entry *selbs;
1569 struct ieee80211_channel *chan;
1570 struct ieee80211com *ic = vap->iv_ic;
1571
1572 KASSERT(vap->iv_opmode == IEEE80211_M_IBSS ||
1573 vap->iv_opmode == IEEE80211_M_AHDEMO ||
1574 vap->iv_opmode == IEEE80211_M_MBSS,
1575 ("wrong opmode %u", vap->iv_opmode));
1576
1577 if (st->st_newscan) {
1578 sta_update_notseen(st);
1579 st->st_newscan = 0;
1580 }
1581 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1582 /*
1583 * Manual/background scan, don't select+join the
1584 * bss, just return. The scanning framework will
1585 * handle notification that this has completed.
1586 */
1587 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1588 return 1;
1589 }
1590 /*
1591 * Automatic sequencing; look for a candidate and
1592 * if found join the network.
1593 */
1594 /* NB: unlocked read should be ok */
1595 if (TAILQ_FIRST(&st->st_entry) == NULL) {
1596 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1597 "%s: no scan candidate\n", __func__);
1598 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1599 return 0;
1600 notfound:
1601 /* NB: never auto-start a tdma network for slot !0 */
1602 #ifdef IEEE80211_SUPPORT_TDMA
1603 if (vap->iv_des_nssid &&
1604 ((vap->iv_caps & IEEE80211_C_TDMA) == 0 ||
1605 ieee80211_tdma_getslot(vap) == 0)) {
1606 #else
1607 if (vap->iv_des_nssid) {
1608 #endif
1609 /*
1610 * No existing adhoc network to join and we have
1611 * an ssid; start one up. If no channel was
1612 * specified, try to select a channel.
1613 */
1614 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC ||
1615 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
1616 chan = adhoc_pick_channel(ss, 0);
1617 } else
1618 chan = vap->iv_des_chan;
1619 if (chan != NULL) {
1620 /*
1621 * Create a HT capable IBSS; the per-node
1622 * probe request/response will result in
1623 * "correct" rate control capabilities being
1624 * negotiated.
1625 */
1626 chan = ieee80211_ht_adjust_channel(ic,
1627 chan, vap->iv_flags_ht);
1628 ieee80211_create_ibss(vap, chan);
1629 return 1;
1630 }
1631 }
1632 /*
1633 * If nothing suitable was found decrement
1634 * the failure counts so entries will be
1635 * reconsidered the next time around. We
1636 * really want to do this only for sta's
1637 * where we've previously had some success.
1638 */
1639 sta_dec_fails(st);
1640 st->st_newscan = 1;
1641 return 0; /* restart scan */
1642 }
1643 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1644 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1645 return (selbs != NULL);
1646 if (selbs == NULL)
1647 goto notfound;
1648 chan = selbs->base.se_chan;
1649 if (selbs->se_flags & STA_DEMOTE11B)
1650 chan = demote11b(vap, chan);
1651 /*
1652 * If HT is available, make it a possibility here.
1653 * The intent is to enable HT20/HT40 when joining a non-HT
1654 * IBSS node; we can then advertise HT IEs and speak HT
1655 * to any subsequent nodes that support it.
1656 */
1657 chan = ieee80211_ht_adjust_channel(ic,
1658 chan, vap->iv_flags_ht);
1659 if (!ieee80211_sta_join(vap, chan, &selbs->base))
1660 goto notfound;
1661 return 1; /* terminate scan */
1662 }
1663
1664 /*
1665 * Age entries in the scan cache.
1666 */
1667 static void
1668 adhoc_age(struct ieee80211_scan_state *ss)
1669 {
1670 struct sta_table *st = ss->ss_priv;
1671 struct sta_entry *se, *next;
1672
1673 IEEE80211_SCAN_TABLE_LOCK(st);
1674 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) {
1675 if (se->se_notseen > STA_PURGE_SCANS) {
1676 TAILQ_REMOVE(&st->st_entry, se, se_list);
1677 LIST_REMOVE(se, se_hash);
1678 ieee80211_ies_cleanup(&se->base.se_ies);
1679 IEEE80211_FREE(se, M_80211_SCAN);
1680 }
1681 }
1682 IEEE80211_SCAN_TABLE_UNLOCK(st);
1683 }
1684
1685 static const struct ieee80211_scanner adhoc_default = {
1686 .scan_name = "default",
1687 .scan_attach = sta_attach,
1688 .scan_detach = sta_detach,
1689 .scan_start = adhoc_start,
1690 .scan_restart = sta_restart,
1691 .scan_cancel = sta_cancel,
1692 .scan_end = adhoc_pick_bss,
1693 .scan_flush = sta_flush,
1694 .scan_pickchan = adhoc_pick_channel,
1695 .scan_add = sta_add,
1696 .scan_age = adhoc_age,
1697 .scan_iterate = sta_iterate,
1698 .scan_assoc_fail = sta_assoc_fail,
1699 .scan_assoc_success = sta_assoc_success,
1700 };
1701 IEEE80211_SCANNER_ALG(ibss, IEEE80211_M_IBSS, adhoc_default);
1702 IEEE80211_SCANNER_ALG(ahdemo, IEEE80211_M_AHDEMO, adhoc_default);
1703
1704 static int
1705 ap_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1706 {
1707 struct sta_table *st = ss->ss_priv;
1708
1709 makescanlist(ss, vap, staScanTable);
1710
1711 if (ss->ss_mindwell == 0)
1712 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */
1713 if (ss->ss_maxdwell == 0)
1714 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
1715
1716 st->st_scangen++;
1717 st->st_newscan = 1;
1718
1719 return 0;
1720 }
1721
1722 /*
1723 * Cancel an ongoing scan.
1724 */
1725 static int
1726 ap_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1727 {
1728 return 0;
1729 }
1730
1731 /*
1732 * Pick a quiet channel to use for ap operation.
1733 */
1734 static struct ieee80211_channel *
1735 ap_pick_channel(struct ieee80211_scan_state *ss, int flags)
1736 {
1737 struct sta_table *st = ss->ss_priv;
1738 struct ieee80211_channel *bestchan = NULL;
1739 int i;
1740
1741 /* XXX select channel more intelligently, e.g. channel spread, power */
1742 /* NB: use scan list order to preserve channel preference */
1743 for (i = 0; i < ss->ss_last; i++) {
1744 struct ieee80211_channel *chan = ss->ss_chans[i];
1745 /*
1746 * If the channel is unoccupied the max rssi
1747 * should be zero; just take it. Otherwise
1748 * track the channel with the lowest rssi and
1749 * use that when all channels appear occupied.
1750 */
1751 if (IEEE80211_IS_CHAN_RADAR(chan))
1752 continue;
1753 if (IEEE80211_IS_CHAN_NOHOSTAP(chan))
1754 continue;
1755 /* check channel attributes for band compatibility */
1756 if (flags != 0 && (chan->ic_flags & flags) != flags)
1757 continue;
1758 KASSERT(sizeof(chan->ic_ieee) == 1, ("ic_chan size"));
1759 /* XXX channel have interference */
1760 if (st->st_maxrssi[chan->ic_ieee] == 0) {
1761 /* XXX use other considerations */
1762 return chan;
1763 }
1764 if (bestchan == NULL ||
1765 st->st_maxrssi[chan->ic_ieee] < st->st_maxrssi[bestchan->ic_ieee])
1766 bestchan = chan;
1767 }
1768 return bestchan;
1769 }
1770
1771 /*
1772 * Pick a quiet channel to use for ap operation.
1773 */
1774 static int
1775 ap_end(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1776 {
1777 struct ieee80211com *ic = vap->iv_ic;
1778 struct ieee80211_channel *bestchan;
1779
1780 KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP,
1781 ("wrong opmode %u", vap->iv_opmode));
1782 bestchan = ap_pick_channel(ss, 0);
1783 if (bestchan == NULL) {
1784 /* no suitable channel, should not happen */
1785 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1786 "%s: no suitable channel! (should not happen)\n", __func__);
1787 /* XXX print something? */
1788 return 0; /* restart scan */
1789 }
1790 /*
1791 * If this is a dynamic turbo channel, start with the unboosted one.
1792 */
1793 if (IEEE80211_IS_CHAN_TURBO(bestchan)) {
1794 bestchan = ieee80211_find_channel(ic, bestchan->ic_freq,
1795 bestchan->ic_flags & ~IEEE80211_CHAN_TURBO);
1796 if (bestchan == NULL) {
1797 /* should never happen ?? */
1798 return 0;
1799 }
1800 }
1801 if (ss->ss_flags & (IEEE80211_SCAN_NOPICK | IEEE80211_SCAN_NOJOIN)) {
1802 /*
1803 * Manual/background scan, don't select+join the
1804 * bss, just return. The scanning framework will
1805 * handle notification that this has completed.
1806 */
1807 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1808 return 1;
1809 }
1810 ieee80211_create_ibss(vap,
1811 ieee80211_ht_adjust_channel(ic, bestchan, vap->iv_flags_ht));
1812 return 1;
1813 }
1814
1815 static const struct ieee80211_scanner ap_default = {
1816 .scan_name = "default",
1817 .scan_attach = sta_attach,
1818 .scan_detach = sta_detach,
1819 .scan_start = ap_start,
1820 .scan_restart = sta_restart,
1821 .scan_cancel = ap_cancel,
1822 .scan_end = ap_end,
1823 .scan_flush = sta_flush,
1824 .scan_pickchan = ap_pick_channel,
1825 .scan_add = sta_add,
1826 .scan_age = adhoc_age,
1827 .scan_iterate = sta_iterate,
1828 .scan_assoc_success = sta_assoc_success,
1829 .scan_assoc_fail = sta_assoc_fail,
1830 };
1831 IEEE80211_SCANNER_ALG(ap, IEEE80211_M_HOSTAP, ap_default);
1832
1833 #ifdef IEEE80211_SUPPORT_MESH
1834 /*
1835 * Pick an mbss network to join or find a channel
1836 * to use to start an mbss network.
1837 */
1838 static int
1839 mesh_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1840 {
1841 struct sta_table *st = ss->ss_priv;
1842 struct ieee80211_mesh_state *ms = vap->iv_mesh;
1843 struct sta_entry *selbs;
1844 struct ieee80211_channel *chan;
1845
1846 KASSERT(vap->iv_opmode == IEEE80211_M_MBSS,
1847 ("wrong opmode %u", vap->iv_opmode));
1848
1849 if (st->st_newscan) {
1850 sta_update_notseen(st);
1851 st->st_newscan = 0;
1852 }
1853 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1854 /*
1855 * Manual/background scan, don't select+join the
1856 * bss, just return. The scanning framework will
1857 * handle notification that this has completed.
1858 */
1859 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1860 return 1;
1861 }
1862 /*
1863 * Automatic sequencing; look for a candidate and
1864 * if found join the network.
1865 */
1866 /* NB: unlocked read should be ok */
1867 if (TAILQ_FIRST(&st->st_entry) == NULL) {
1868 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1869 "%s: no scan candidate\n", __func__);
1870 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1871 return 0;
1872 notfound:
1873 if (ms->ms_idlen != 0) {
1874 /*
1875 * No existing mbss network to join and we have
1876 * a meshid; start one up. If no channel was
1877 * specified, try to select a channel.
1878 */
1879 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC ||
1880 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
1881 struct ieee80211com *ic = vap->iv_ic;
1882
1883 chan = adhoc_pick_channel(ss, 0);
1884 if (chan != NULL)
1885 chan = ieee80211_ht_adjust_channel(ic,
1886 chan, vap->iv_flags_ht);
1887 } else
1888 chan = vap->iv_des_chan;
1889 if (chan != NULL) {
1890 ieee80211_create_ibss(vap, chan);
1891 return 1;
1892 }
1893 }
1894 /*
1895 * If nothing suitable was found decrement
1896 * the failure counts so entries will be
1897 * reconsidered the next time around. We
1898 * really want to do this only for sta's
1899 * where we've previously had some success.
1900 */
1901 sta_dec_fails(st);
1902 st->st_newscan = 1;
1903 return 0; /* restart scan */
1904 }
1905 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1906 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1907 return (selbs != NULL);
1908 if (selbs == NULL)
1909 goto notfound;
1910 chan = selbs->base.se_chan;
1911 if (selbs->se_flags & STA_DEMOTE11B)
1912 chan = demote11b(vap, chan);
1913 if (!ieee80211_sta_join(vap, chan, &selbs->base))
1914 goto notfound;
1915 return 1; /* terminate scan */
1916 }
1917
1918 static const struct ieee80211_scanner mesh_default = {
1919 .scan_name = "default",
1920 .scan_attach = sta_attach,
1921 .scan_detach = sta_detach,
1922 .scan_start = adhoc_start,
1923 .scan_restart = sta_restart,
1924 .scan_cancel = sta_cancel,
1925 .scan_end = mesh_pick_bss,
1926 .scan_flush = sta_flush,
1927 .scan_pickchan = adhoc_pick_channel,
1928 .scan_add = sta_add,
1929 .scan_age = adhoc_age,
1930 .scan_iterate = sta_iterate,
1931 .scan_assoc_fail = sta_assoc_fail,
1932 .scan_assoc_success = sta_assoc_success,
1933 };
1934 IEEE80211_SCANNER_ALG(mesh, IEEE80211_M_MBSS, mesh_default);
1935 #endif /* IEEE80211_SUPPORT_MESH */
Cache object: c448d633e995a1197ce259beca1ab244
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