1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2002-2009 Sam Leffler, Errno Consulting
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30
31 /*
32 * IEEE 802.11 station scanning support.
33 */
34 #include "opt_wlan.h"
35
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/kernel.h>
39 #include <sys/endian.h>
40 #include <sys/malloc.h>
41 #include <sys/module.h>
42
43 #include <sys/socket.h>
44
45 #include <net/if.h>
46 #include <net/if_var.h>
47 #include <net/if_media.h>
48 #include <net/ethernet.h>
49
50 #include <net80211/ieee80211_var.h>
51 #include <net80211/ieee80211_input.h>
52 #include <net80211/ieee80211_regdomain.h>
53 #ifdef IEEE80211_SUPPORT_TDMA
54 #include <net80211/ieee80211_tdma.h>
55 #endif
56 #ifdef IEEE80211_SUPPORT_MESH
57 #include <net80211/ieee80211_mesh.h>
58 #endif
59 #include <net80211/ieee80211_ratectl.h>
60 #include <net80211/ieee80211_vht.h>
61
62 #include <net/bpf.h>
63
64 /*
65 * Parameters for managing cache entries:
66 *
67 * o a station with STA_FAILS_MAX failures is not considered
68 * when picking a candidate
69 * o a station that hasn't had an update in STA_PURGE_SCANS
70 * (background) scans is discarded
71 * o after STA_FAILS_AGE seconds we clear the failure count
72 */
73 #define STA_FAILS_MAX 2 /* assoc failures before ignored */
74 #define STA_FAILS_AGE (2*60) /* time before clearing fails (secs) */
75 #define STA_PURGE_SCANS 2 /* age for purging entries (scans) */
76
77 /* XXX tunable */
78 #define STA_RSSI_MIN 8 /* min acceptable rssi */
79 #define STA_RSSI_MAX 40 /* max rssi for comparison */
80
81 struct sta_entry {
82 struct ieee80211_scan_entry base;
83 TAILQ_ENTRY(sta_entry) se_list;
84 LIST_ENTRY(sta_entry) se_hash;
85 uint8_t se_fails; /* failure to associate count */
86 uint8_t se_seen; /* seen during current scan */
87 uint8_t se_notseen; /* not seen in previous scans */
88 uint8_t se_flags;
89 #define STA_DEMOTE11B 0x01 /* match w/ demoted 11b chan */
90 uint32_t se_avgrssi; /* LPF rssi state */
91 unsigned long se_lastupdate; /* time of last update */
92 unsigned long se_lastfail; /* time of last failure */
93 unsigned long se_lastassoc; /* time of last association */
94 u_int se_scangen; /* iterator scan gen# */
95 u_int se_countrygen; /* gen# of last cc notify */
96 };
97
98 #define STA_HASHSIZE 32
99 /* simple hash is enough for variation of macaddr */
100 #define STA_HASH(addr) \
101 (((const uint8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % STA_HASHSIZE)
102
103 #define MAX_IEEE_CHAN 256 /* max acceptable IEEE chan # */
104 CTASSERT(MAX_IEEE_CHAN >= 256);
105
106 struct sta_table {
107 ieee80211_scan_table_lock_t st_lock; /* on scan table */
108 TAILQ_HEAD(, sta_entry) st_entry; /* all entries */
109 LIST_HEAD(, sta_entry) st_hash[STA_HASHSIZE];
110 ieee80211_scan_iter_lock_t st_scanlock; /* on st_scaniter */
111 u_int st_scaniter; /* gen# for iterator */
112 u_int st_scangen; /* scan generation # */
113 int st_newscan;
114 /* ap-related state */
115 int st_maxrssi[MAX_IEEE_CHAN];
116 };
117
118 static void sta_flush_table(struct sta_table *);
119 /*
120 * match_bss returns a bitmask describing if an entry is suitable
121 * for use. If non-zero the entry was deemed not suitable and it's
122 * contents explains why. The following flags are or'd to this
123 * mask and can be used to figure out why the entry was rejected.
124 */
125 #define MATCH_CHANNEL 0x00001 /* channel mismatch */
126 #define MATCH_CAPINFO 0x00002 /* capabilities mismatch, e.g. no ess */
127 #define MATCH_PRIVACY 0x00004 /* privacy mismatch */
128 #define MATCH_RATE 0x00008 /* rate set mismatch */
129 #define MATCH_SSID 0x00010 /* ssid mismatch */
130 #define MATCH_BSSID 0x00020 /* bssid mismatch */
131 #define MATCH_FAILS 0x00040 /* too many failed auth attempts */
132 #define MATCH_NOTSEEN 0x00080 /* not seen in recent scans */
133 #define MATCH_RSSI 0x00100 /* rssi deemed too low to use */
134 #define MATCH_CC 0x00200 /* country code mismatch */
135 #ifdef IEEE80211_SUPPORT_TDMA
136 #define MATCH_TDMA_NOIE 0x00400 /* no TDMA ie */
137 #define MATCH_TDMA_NOTMASTER 0x00800 /* not TDMA master */
138 #define MATCH_TDMA_NOSLOT 0x01000 /* all TDMA slots occupied */
139 #define MATCH_TDMA_LOCAL 0x02000 /* local address */
140 #define MATCH_TDMA_VERSION 0x04000 /* protocol version mismatch */
141 #endif
142 #define MATCH_MESH_NOID 0x10000 /* no MESHID ie */
143 #define MATCH_MESHID 0x20000 /* meshid mismatch */
144 static int match_bss(struct ieee80211vap *,
145 const struct ieee80211_scan_state *, struct sta_entry *, int);
146 static void adhoc_age(struct ieee80211_scan_state *);
147
148 static __inline int
149 isocmp(const uint8_t cc1[], const uint8_t cc2[])
150 {
151 return (cc1[0] == cc2[0] && cc1[1] == cc2[1]);
152 }
153
154 /* number of references from net80211 layer */
155 static int nrefs = 0;
156 /*
157 * Module glue.
158 */
159 IEEE80211_SCANNER_MODULE(sta, 1);
160
161 /*
162 * Attach prior to any scanning work.
163 */
164 static int
165 sta_attach(struct ieee80211_scan_state *ss)
166 {
167 struct sta_table *st;
168
169 st = (struct sta_table *) IEEE80211_MALLOC(sizeof(struct sta_table),
170 M_80211_SCAN,
171 IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
172 if (st == NULL)
173 return 0;
174 IEEE80211_SCAN_TABLE_LOCK_INIT(st, "scantable");
175 IEEE80211_SCAN_ITER_LOCK_INIT(st, "scangen");
176 TAILQ_INIT(&st->st_entry);
177 ss->ss_priv = st;
178 nrefs++; /* NB: we assume caller locking */
179 return 1;
180 }
181
182 /*
183 * Cleanup any private state.
184 */
185 static int
186 sta_detach(struct ieee80211_scan_state *ss)
187 {
188 struct sta_table *st = ss->ss_priv;
189
190 if (st != NULL) {
191 sta_flush_table(st);
192 IEEE80211_SCAN_TABLE_LOCK_DESTROY(st);
193 IEEE80211_SCAN_ITER_LOCK_DESTROY(st);
194 IEEE80211_FREE(st, M_80211_SCAN);
195 KASSERT(nrefs > 0, ("imbalanced attach/detach"));
196 nrefs--; /* NB: we assume caller locking */
197 }
198 return 1;
199 }
200
201 /*
202 * Flush all per-scan state.
203 */
204 static int
205 sta_flush(struct ieee80211_scan_state *ss)
206 {
207 struct sta_table *st = ss->ss_priv;
208
209 IEEE80211_SCAN_TABLE_LOCK(st);
210 sta_flush_table(st);
211 IEEE80211_SCAN_TABLE_UNLOCK(st);
212 ss->ss_last = 0;
213 return 0;
214 }
215
216 /*
217 * Flush all entries in the scan cache.
218 */
219 static void
220 sta_flush_table(struct sta_table *st)
221 {
222 struct sta_entry *se, *next;
223
224 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) {
225 TAILQ_REMOVE(&st->st_entry, se, se_list);
226 LIST_REMOVE(se, se_hash);
227 ieee80211_ies_cleanup(&se->base.se_ies);
228 IEEE80211_FREE(se, M_80211_SCAN);
229 }
230 memset(st->st_maxrssi, 0, sizeof(st->st_maxrssi));
231 }
232
233 /*
234 * Process a beacon or probe response frame; create an
235 * entry in the scan cache or update any previous entry.
236 */
237 static int
238 sta_add(struct ieee80211_scan_state *ss,
239 struct ieee80211_channel *curchan,
240 const struct ieee80211_scanparams *sp,
241 const struct ieee80211_frame *wh,
242 int subtype, int rssi, int noise)
243 {
244 #define ISPROBE(_st) ((_st) == IEEE80211_FC0_SUBTYPE_PROBE_RESP)
245 #define PICK1ST(_ss) \
246 ((ss->ss_flags & (IEEE80211_SCAN_PICK1ST | IEEE80211_SCAN_GOTPICK)) == \
247 IEEE80211_SCAN_PICK1ST)
248 struct sta_table *st = ss->ss_priv;
249 const uint8_t *macaddr = wh->i_addr2;
250 struct ieee80211vap *vap = ss->ss_vap;
251 struct ieee80211com *ic = vap->iv_ic;
252 struct ieee80211_channel *c;
253 struct sta_entry *se;
254 struct ieee80211_scan_entry *ise;
255 int hash;
256
257 hash = STA_HASH(macaddr);
258
259 IEEE80211_SCAN_TABLE_LOCK(st);
260 LIST_FOREACH(se, &st->st_hash[hash], se_hash)
261 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr))
262 goto found;
263 se = (struct sta_entry *) IEEE80211_MALLOC(sizeof(struct sta_entry),
264 M_80211_SCAN, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
265 if (se == NULL) {
266 IEEE80211_SCAN_TABLE_UNLOCK(st);
267 return 0;
268 }
269 se->se_scangen = st->st_scaniter-1;
270 se->se_avgrssi = IEEE80211_RSSI_DUMMY_MARKER;
271 IEEE80211_ADDR_COPY(se->base.se_macaddr, macaddr);
272 TAILQ_INSERT_TAIL(&st->st_entry, se, se_list);
273 LIST_INSERT_HEAD(&st->st_hash[hash], se, se_hash);
274 found:
275 ise = &se->base;
276 /* XXX ap beaconing multiple ssid w/ same bssid */
277 if (sp->ssid[1] != 0 &&
278 (ISPROBE(subtype) || ise->se_ssid[1] == 0))
279 memcpy(ise->se_ssid, sp->ssid, 2+sp->ssid[1]);
280 KASSERT(sp->rates[1] <= IEEE80211_RATE_MAXSIZE,
281 ("rate set too large: %u", sp->rates[1]));
282 memcpy(ise->se_rates, sp->rates, 2+sp->rates[1]);
283 if (sp->xrates != NULL) {
284 /* XXX validate xrates[1] */
285 KASSERT(sp->xrates[1] <= IEEE80211_RATE_MAXSIZE,
286 ("xrate set too large: %u", sp->xrates[1]));
287 memcpy(ise->se_xrates, sp->xrates, 2+sp->xrates[1]);
288 } else
289 ise->se_xrates[1] = 0;
290 IEEE80211_ADDR_COPY(ise->se_bssid, wh->i_addr3);
291 if ((sp->status & IEEE80211_BPARSE_OFFCHAN) == 0) {
292 /*
293 * Record rssi data using extended precision LPF filter.
294 *
295 * NB: use only on-channel data to insure we get a good
296 * estimate of the signal we'll see when associated.
297 */
298 IEEE80211_RSSI_LPF(se->se_avgrssi, rssi);
299 ise->se_rssi = IEEE80211_RSSI_GET(se->se_avgrssi);
300 ise->se_noise = noise;
301 }
302 memcpy(ise->se_tstamp.data, sp->tstamp, sizeof(ise->se_tstamp));
303 ise->se_intval = sp->bintval;
304 ise->se_capinfo = sp->capinfo;
305 #ifdef IEEE80211_SUPPORT_MESH
306 if (sp->meshid != NULL && sp->meshid[1] != 0)
307 memcpy(ise->se_meshid, sp->meshid, 2+sp->meshid[1]);
308 #endif
309 /*
310 * Beware of overriding se_chan for frames seen
311 * off-channel; this can cause us to attempt an
312 * association on the wrong channel.
313 */
314 if (sp->status & IEEE80211_BPARSE_OFFCHAN) {
315 /*
316 * Off-channel, locate the home/bss channel for the sta
317 * using the value broadcast in the DSPARMS ie. We know
318 * sp->chan has this value because it's used to calculate
319 * IEEE80211_BPARSE_OFFCHAN.
320 */
321 c = ieee80211_find_channel_byieee(ic, sp->chan,
322 curchan->ic_flags);
323 if (c != NULL) {
324 ise->se_chan = c;
325 } else if (ise->se_chan == NULL) {
326 /* should not happen, pick something */
327 ise->se_chan = curchan;
328 }
329 } else
330 ise->se_chan = curchan;
331
332 /* VHT demotion */
333 if (IEEE80211_IS_CHAN_VHT(ise->se_chan) && sp->vhtcap == NULL) {
334 IEEE80211_DPRINTF(vap, IEEE80211_MSG_11N,
335 "%s: demoting VHT->HT %d/0x%08x\n",
336 __func__, ise->se_chan->ic_freq, ise->se_chan->ic_flags);
337 /* Demote legacy networks to a non-VHT channel. */
338 c = ieee80211_find_channel(ic, ise->se_chan->ic_freq,
339 ise->se_chan->ic_flags & ~IEEE80211_CHAN_VHT);
340 KASSERT(c != NULL,
341 ("no non-VHT channel %u", ise->se_chan->ic_ieee));
342 ise->se_chan = c;
343 }
344
345 /* HT demotion */
346 if (IEEE80211_IS_CHAN_HT(ise->se_chan) && sp->htcap == NULL) {
347 /* Demote legacy networks to a non-HT channel. */
348 IEEE80211_DPRINTF(vap, IEEE80211_MSG_11N,
349 "%s: demoting HT->legacy %d/0x%08x\n",
350 __func__, ise->se_chan->ic_freq, ise->se_chan->ic_flags);
351 c = ieee80211_find_channel(ic, ise->se_chan->ic_freq,
352 ise->se_chan->ic_flags & ~IEEE80211_CHAN_HT);
353 KASSERT(c != NULL,
354 ("no legacy channel %u", ise->se_chan->ic_ieee));
355 ise->se_chan = c;
356 }
357
358 ise->se_fhdwell = sp->fhdwell;
359 ise->se_fhindex = sp->fhindex;
360 ise->se_erp = sp->erp;
361 ise->se_timoff = sp->timoff;
362 if (sp->tim != NULL) {
363 const struct ieee80211_tim_ie *tim =
364 (const struct ieee80211_tim_ie *) sp->tim;
365 ise->se_dtimperiod = tim->tim_period;
366 }
367 if (sp->country != NULL) {
368 const struct ieee80211_country_ie *cie =
369 (const struct ieee80211_country_ie *) sp->country;
370 /*
371 * If 11d is enabled and we're attempting to join a bss
372 * that advertises it's country code then compare our
373 * current settings to what we fetched from the country ie.
374 * If our country code is unspecified or different then
375 * dispatch an event to user space that identifies the
376 * country code so our regdomain config can be changed.
377 */
378 /* XXX only for STA mode? */
379 if ((IEEE80211_IS_CHAN_11D(ise->se_chan) ||
380 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) &&
381 (ic->ic_regdomain.country == CTRY_DEFAULT ||
382 !isocmp(cie->cc, ic->ic_regdomain.isocc))) {
383 /* only issue one notify event per scan */
384 if (se->se_countrygen != st->st_scangen) {
385 ieee80211_notify_country(vap, ise->se_bssid,
386 cie->cc);
387 se->se_countrygen = st->st_scangen;
388 }
389 }
390 ise->se_cc[0] = cie->cc[0];
391 ise->se_cc[1] = cie->cc[1];
392 }
393 /* NB: no need to setup ie ptrs; they are not (currently) used */
394 (void) ieee80211_ies_init(&ise->se_ies, sp->ies, sp->ies_len);
395
396 /* clear failure count after STA_FAIL_AGE passes */
397 if (se->se_fails && (ticks - se->se_lastfail) > STA_FAILS_AGE*hz) {
398 se->se_fails = 0;
399 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, macaddr,
400 "%s: fails %u", __func__, se->se_fails);
401 }
402
403 se->se_lastupdate = ticks; /* update time */
404 se->se_seen = 1;
405 se->se_notseen = 0;
406
407 KASSERT(sizeof(sp->bchan) == 1, ("bchan size"));
408 if (rssi > st->st_maxrssi[sp->bchan])
409 st->st_maxrssi[sp->bchan] = rssi;
410
411 IEEE80211_SCAN_TABLE_UNLOCK(st);
412
413 /*
414 * If looking for a quick choice and nothing's
415 * been found check here.
416 */
417 if (PICK1ST(ss) && match_bss(vap, ss, se, IEEE80211_MSG_SCAN) == 0)
418 ss->ss_flags |= IEEE80211_SCAN_GOTPICK;
419
420 return 1;
421 #undef PICK1ST
422 #undef ISPROBE
423 }
424
425 /*
426 * Check if a channel is excluded by user request.
427 */
428 static int
429 isexcluded(struct ieee80211vap *vap, const struct ieee80211_channel *c)
430 {
431 return (isclr(vap->iv_ic->ic_chan_active, c->ic_ieee) ||
432 (vap->iv_des_chan != IEEE80211_CHAN_ANYC &&
433 c->ic_freq != vap->iv_des_chan->ic_freq));
434 }
435
436 static struct ieee80211_channel *
437 find11gchannel(struct ieee80211com *ic, int i, int freq)
438 {
439 struct ieee80211_channel *c;
440 int j;
441
442 /*
443 * The normal ordering in the channel list is b channel
444 * immediately followed by g so optimize the search for
445 * this. We'll still do a full search just in case.
446 */
447 for (j = i+1; j < ic->ic_nchans; j++) {
448 c = &ic->ic_channels[j];
449 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c))
450 return c;
451 }
452 for (j = 0; j < i; j++) {
453 c = &ic->ic_channels[j];
454 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c))
455 return c;
456 }
457 return NULL;
458 }
459
460 static const u_int chanflags[IEEE80211_MODE_MAX] = {
461 [IEEE80211_MODE_AUTO] = IEEE80211_CHAN_B,
462 [IEEE80211_MODE_11A] = IEEE80211_CHAN_A,
463 [IEEE80211_MODE_11B] = IEEE80211_CHAN_B,
464 [IEEE80211_MODE_11G] = IEEE80211_CHAN_G,
465 [IEEE80211_MODE_FH] = IEEE80211_CHAN_FHSS,
466 /* check base channel */
467 [IEEE80211_MODE_TURBO_A] = IEEE80211_CHAN_A,
468 [IEEE80211_MODE_TURBO_G] = IEEE80211_CHAN_G,
469 [IEEE80211_MODE_STURBO_A] = IEEE80211_CHAN_ST,
470 [IEEE80211_MODE_HALF] = IEEE80211_CHAN_HALF,
471 [IEEE80211_MODE_QUARTER] = IEEE80211_CHAN_QUARTER,
472 /* check legacy */
473 [IEEE80211_MODE_11NA] = IEEE80211_CHAN_A,
474 [IEEE80211_MODE_11NG] = IEEE80211_CHAN_G,
475 [IEEE80211_MODE_VHT_5GHZ] = IEEE80211_CHAN_A,
476 [IEEE80211_MODE_VHT_2GHZ] = IEEE80211_CHAN_G,
477 };
478
479 static void
480 add_channels(struct ieee80211vap *vap,
481 struct ieee80211_scan_state *ss,
482 enum ieee80211_phymode mode, const uint16_t freq[], int nfreq)
483 {
484 struct ieee80211com *ic = vap->iv_ic;
485 struct ieee80211_channel *c, *cg;
486 u_int modeflags;
487 int i;
488
489 KASSERT(mode < nitems(chanflags), ("Unexpected mode %u", mode));
490 modeflags = chanflags[mode];
491 for (i = 0; i < nfreq; i++) {
492 if (ss->ss_last >= IEEE80211_SCAN_MAX)
493 break;
494
495 c = ieee80211_find_channel(ic, freq[i], modeflags);
496 if (c == NULL || isexcluded(vap, c))
497 continue;
498 if (mode == IEEE80211_MODE_AUTO) {
499 KASSERT(IEEE80211_IS_CHAN_B(c),
500 ("%s: wrong channel for 'auto' mode %u / %u\n",
501 __func__, c->ic_freq, c->ic_flags));
502
503 /*
504 * XXX special-case 11b/g channels so we select
505 * the g channel if both are present.
506 */
507 if ((cg = find11gchannel(ic, i, c->ic_freq)) != NULL)
508 c = cg;
509 }
510 ss->ss_chans[ss->ss_last++] = c;
511 }
512 }
513
514 struct scanlist {
515 uint16_t mode;
516 uint16_t count;
517 const uint16_t *list;
518 };
519
520 static int
521 checktable(const struct scanlist *scan, const struct ieee80211_channel *c)
522 {
523 int i;
524
525 for (; scan->list != NULL; scan++) {
526 for (i = 0; i < scan->count; i++)
527 if (scan->list[i] == c->ic_freq)
528 return 1;
529 }
530 return 0;
531 }
532
533 static int
534 onscanlist(const struct ieee80211_scan_state *ss,
535 const struct ieee80211_channel *c)
536 {
537 int i;
538
539 for (i = 0; i < ss->ss_last; i++)
540 if (ss->ss_chans[i] == c)
541 return 1;
542 return 0;
543 }
544
545 static void
546 sweepchannels(struct ieee80211_scan_state *ss, struct ieee80211vap *vap,
547 const struct scanlist table[])
548 {
549 struct ieee80211com *ic = vap->iv_ic;
550 struct ieee80211_channel *c;
551 int i;
552
553 for (i = 0; i < ic->ic_nchans; i++) {
554 if (ss->ss_last >= IEEE80211_SCAN_MAX)
555 break;
556
557 c = &ic->ic_channels[i];
558 /*
559 * Ignore dynamic turbo channels; we scan them
560 * in normal mode (i.e. not boosted). Likewise
561 * for HT/VHT channels, they get scanned using
562 * legacy rates.
563 */
564 if (IEEE80211_IS_CHAN_DTURBO(c) || IEEE80211_IS_CHAN_HT(c) ||
565 IEEE80211_IS_CHAN_VHT(c))
566 continue;
567
568 /*
569 * If a desired mode was specified, scan only
570 * channels that satisfy that constraint.
571 */
572 if (vap->iv_des_mode != IEEE80211_MODE_AUTO &&
573 vap->iv_des_mode != ieee80211_chan2mode(c))
574 continue;
575
576 /*
577 * Skip channels excluded by user request.
578 */
579 if (isexcluded(vap, c))
580 continue;
581
582 /*
583 * Add the channel unless it is listed in the
584 * fixed scan order tables. This insures we
585 * don't sweep back in channels we filtered out
586 * above.
587 */
588 if (checktable(table, c))
589 continue;
590
591 /* Add channel to scanning list. */
592 ss->ss_chans[ss->ss_last++] = c;
593 }
594 /*
595 * Explicitly add any desired channel if:
596 * - not already on the scan list
597 * - allowed by any desired mode constraint
598 * - there is space in the scan list
599 * This allows the channel to be used when the filtering
600 * mechanisms would otherwise elide it (e.g HT, turbo).
601 */
602 c = vap->iv_des_chan;
603 if (c != IEEE80211_CHAN_ANYC &&
604 !onscanlist(ss, c) &&
605 (vap->iv_des_mode == IEEE80211_MODE_AUTO ||
606 vap->iv_des_mode == ieee80211_chan2mode(c)) &&
607 ss->ss_last < IEEE80211_SCAN_MAX)
608 ss->ss_chans[ss->ss_last++] = c;
609 }
610
611 static void
612 makescanlist(struct ieee80211_scan_state *ss, struct ieee80211vap *vap,
613 const struct scanlist table[])
614 {
615 const struct scanlist *scan;
616 enum ieee80211_phymode mode;
617
618 ss->ss_last = 0;
619 /*
620 * Use the table of ordered channels to construct the list
621 * of channels for scanning. Any channels in the ordered
622 * list not in the master list will be discarded.
623 */
624 for (scan = table; scan->list != NULL; scan++) {
625 mode = scan->mode;
626
627 switch (mode) {
628 case IEEE80211_MODE_11B:
629 if (vap->iv_des_mode == IEEE80211_MODE_11B)
630 break;
631
632 /*
633 * The scan table marks 2.4Ghz channels as b
634 * so if the desired mode is 11g / 11ng / 11acg,
635 * then use the 11b channel list but upgrade the mode.
636 *
637 * NB: 11b -> AUTO lets add_channels upgrade an
638 * 11b channel to 11g if available.
639 */
640 if (vap->iv_des_mode == IEEE80211_MODE_AUTO ||
641 vap->iv_des_mode == IEEE80211_MODE_11G ||
642 vap->iv_des_mode == IEEE80211_MODE_11NG ||
643 vap->iv_des_mode == IEEE80211_MODE_VHT_2GHZ) {
644 mode = vap->iv_des_mode;
645 break;
646 }
647
648 continue;
649 case IEEE80211_MODE_11A:
650 /* Use 11a channel list for 11na / 11ac modes */
651 if (vap->iv_des_mode == IEEE80211_MODE_11NA ||
652 vap->iv_des_mode == IEEE80211_MODE_VHT_5GHZ) {
653 mode = vap->iv_des_mode;
654 break;
655 }
656
657 /* FALLTHROUGH */
658 default:
659 /*
660 * If a desired mode was specified, scan only
661 * channels that satisfy that constraint.
662 */
663 if (vap->iv_des_mode != IEEE80211_MODE_AUTO &&
664 vap->iv_des_mode != mode)
665 continue;
666 }
667
668 #ifdef IEEE80211_F_XR
669 /* XR does not operate on turbo channels */
670 if ((vap->iv_flags & IEEE80211_F_XR) &&
671 (mode == IEEE80211_MODE_TURBO_A ||
672 mode == IEEE80211_MODE_TURBO_G ||
673 mode == IEEE80211_MODE_STURBO_A))
674 continue;
675 #endif
676 /*
677 * Add the list of the channels; any that are not
678 * in the master channel list will be discarded.
679 */
680 add_channels(vap, ss, mode, scan->list, scan->count);
681 }
682
683 /*
684 * Add the channels from the ic that are not present
685 * in the table.
686 */
687 sweepchannels(ss, vap, table);
688 }
689
690 static const uint16_t rcl1[] = /* 8 FCC channel: 52, 56, 60, 64, 36, 40, 44, 48 */
691 { 5260, 5280, 5300, 5320, 5180, 5200, 5220, 5240 };
692 static const uint16_t rcl2[] = /* 4 MKK channels: 34, 38, 42, 46 */
693 { 5170, 5190, 5210, 5230 };
694 static const uint16_t rcl3[] = /* 2.4Ghz ch: 1,6,11,7,13 */
695 { 2412, 2437, 2462, 2442, 2472 };
696 static const uint16_t rcl4[] = /* 5 FCC channel: 149, 153, 161, 165 */
697 { 5745, 5765, 5785, 5805, 5825 };
698 static const uint16_t rcl7[] = /* 11 ETSI channel: 100,104,108,112,116,120,124,128,132,136,140 */
699 { 5500, 5520, 5540, 5560, 5580, 5600, 5620, 5640, 5660, 5680, 5700 };
700 static const uint16_t rcl8[] = /* 2.4Ghz ch: 2,3,4,5,8,9,10,12 */
701 { 2417, 2422, 2427, 2432, 2447, 2452, 2457, 2467 };
702 static const uint16_t rcl9[] = /* 2.4Ghz ch: 14 */
703 { 2484 };
704 static const uint16_t rcl10[] = /* Added Korean channels 2312-2372 */
705 { 2312, 2317, 2322, 2327, 2332, 2337, 2342, 2347, 2352, 2357, 2362, 2367, 2372 };
706 static const uint16_t rcl11[] = /* Added Japan channels in 4.9/5.0 spectrum */
707 { 5040, 5060, 5080, 4920, 4940, 4960, 4980 };
708 #ifdef ATH_TURBO_SCAN
709 static const uint16_t rcl5[] = /* 3 static turbo channels */
710 { 5210, 5250, 5290 };
711 static const uint16_t rcl6[] = /* 2 static turbo channels */
712 { 5760, 5800 };
713 static const uint16_t rcl6x[] = /* 4 FCC3 turbo channels */
714 { 5540, 5580, 5620, 5660 };
715 static const uint16_t rcl12[] = /* 2.4Ghz Turbo channel 6 */
716 { 2437 };
717 static const uint16_t rcl13[] = /* dynamic Turbo channels */
718 { 5200, 5240, 5280, 5765, 5805 };
719 #endif /* ATH_TURBO_SCAN */
720
721 #define X(a) .count = sizeof(a)/sizeof(a[0]), .list = a
722
723 static const struct scanlist staScanTable[] = {
724 { IEEE80211_MODE_11B, X(rcl3) },
725 { IEEE80211_MODE_11A, X(rcl1) },
726 { IEEE80211_MODE_11A, X(rcl2) },
727 { IEEE80211_MODE_11B, X(rcl8) },
728 { IEEE80211_MODE_11B, X(rcl9) },
729 { IEEE80211_MODE_11A, X(rcl4) },
730 #ifdef ATH_TURBO_SCAN
731 { IEEE80211_MODE_STURBO_A, X(rcl5) },
732 { IEEE80211_MODE_STURBO_A, X(rcl6) },
733 { IEEE80211_MODE_TURBO_A, X(rcl6x) },
734 { IEEE80211_MODE_TURBO_A, X(rcl13) },
735 #endif /* ATH_TURBO_SCAN */
736 { IEEE80211_MODE_11A, X(rcl7) },
737 { IEEE80211_MODE_11B, X(rcl10) },
738 { IEEE80211_MODE_11A, X(rcl11) },
739 #ifdef ATH_TURBO_SCAN
740 { IEEE80211_MODE_TURBO_G, X(rcl12) },
741 #endif /* ATH_TURBO_SCAN */
742 { .list = NULL }
743 };
744
745 /*
746 * Start a station-mode scan by populating the channel list.
747 */
748 static int
749 sta_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
750 {
751 struct sta_table *st = ss->ss_priv;
752
753 makescanlist(ss, vap, staScanTable);
754
755 if (ss->ss_mindwell == 0)
756 ss->ss_mindwell = msecs_to_ticks(20); /* 20ms */
757 if (ss->ss_maxdwell == 0)
758 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
759
760 st->st_scangen++;
761 st->st_newscan = 1;
762
763 return 0;
764 }
765
766 /*
767 * Restart a scan, typically a bg scan but can
768 * also be a fg scan that came up empty.
769 */
770 static int
771 sta_restart(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
772 {
773 struct sta_table *st = ss->ss_priv;
774
775 st->st_newscan = 1;
776 return 0;
777 }
778
779 /*
780 * Cancel an ongoing scan.
781 */
782 static int
783 sta_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
784 {
785 return 0;
786 }
787
788 /*
789 * Demote any supplied 11g channel to 11b. There should
790 * always be an 11b channel but we check anyway...
791 */
792 static struct ieee80211_channel *
793 demote11b(struct ieee80211vap *vap, struct ieee80211_channel *chan)
794 {
795 struct ieee80211_channel *c;
796
797 if (IEEE80211_IS_CHAN_ANYG(chan) &&
798 vap->iv_des_mode == IEEE80211_MODE_AUTO) {
799 c = ieee80211_find_channel(vap->iv_ic, chan->ic_freq,
800 (chan->ic_flags &~ (IEEE80211_CHAN_PUREG | IEEE80211_CHAN_G)) |
801 IEEE80211_CHAN_B);
802 if (c != NULL)
803 chan = c;
804 }
805 return chan;
806 }
807
808 static int
809 maxrate(const struct ieee80211_scan_entry *se)
810 {
811 const struct ieee80211_ie_htcap *htcap =
812 (const struct ieee80211_ie_htcap *) se->se_ies.htcap_ie;
813 int rmax, r, i, txstream;
814 uint16_t caps;
815 uint8_t txparams;
816
817 rmax = 0;
818 if (htcap != NULL) {
819 /*
820 * HT station; inspect supported MCS and then adjust
821 * rate by channel width.
822 */
823 txparams = htcap->hc_mcsset[12];
824 if (txparams & 0x3) {
825 /*
826 * TX MCS parameters defined and not equal to RX,
827 * extract the number of spartial streams and
828 * map it to the highest MCS rate.
829 */
830 txstream = ((txparams & 0xc) >> 2) + 1;
831 i = txstream * 8 - 1;
832 } else
833 for (i = 31; i >= 0 && isclr(htcap->hc_mcsset, i); i--);
834 if (i >= 0) {
835 caps = le16dec(&htcap->hc_cap);
836 if ((caps & IEEE80211_HTCAP_CHWIDTH40) &&
837 (caps & IEEE80211_HTCAP_SHORTGI40))
838 rmax = ieee80211_htrates[i].ht40_rate_400ns;
839 else if (caps & IEEE80211_HTCAP_CHWIDTH40)
840 rmax = ieee80211_htrates[i].ht40_rate_800ns;
841 else if (caps & IEEE80211_HTCAP_SHORTGI20)
842 rmax = ieee80211_htrates[i].ht20_rate_400ns;
843 else
844 rmax = ieee80211_htrates[i].ht20_rate_800ns;
845 }
846 }
847 for (i = 0; i < se->se_rates[1]; i++) {
848 r = se->se_rates[2+i] & IEEE80211_RATE_VAL;
849 if (r > rmax)
850 rmax = r;
851 }
852 for (i = 0; i < se->se_xrates[1]; i++) {
853 r = se->se_xrates[2+i] & IEEE80211_RATE_VAL;
854 if (r > rmax)
855 rmax = r;
856 }
857 return rmax;
858 }
859
860 /*
861 * Compare the capabilities of two entries and decide which is
862 * more desirable (return >0 if a is considered better). Note
863 * that we assume compatibility/usability has already been checked
864 * so we don't need to (e.g. validate whether privacy is supported).
865 * Used to select the best scan candidate for association in a BSS.
866 *
867 * TODO: should we take 11n, 11ac into account when selecting the
868 * best? Right now it just compares frequency band and RSSI.
869 */
870 static int
871 sta_compare(const struct sta_entry *a, const struct sta_entry *b)
872 {
873 #define PREFER(_a,_b,_what) do { \
874 if (((_a) ^ (_b)) & (_what)) \
875 return ((_a) & (_what)) ? 1 : -1; \
876 } while (0)
877 int maxa, maxb;
878 int8_t rssia, rssib;
879 int weight;
880
881 /* privacy support */
882 PREFER(a->base.se_capinfo, b->base.se_capinfo,
883 IEEE80211_CAPINFO_PRIVACY);
884
885 /* compare count of previous failures */
886 weight = b->se_fails - a->se_fails;
887 if (abs(weight) > 1)
888 return weight;
889
890 /*
891 * Compare rssi. If the two are considered equivalent
892 * then fallback to other criteria. We threshold the
893 * comparisons to avoid selecting an ap purely by rssi
894 * when both values may be good but one ap is otherwise
895 * more desirable (e.g. an 11b-only ap with stronger
896 * signal than an 11g ap).
897 */
898 rssia = MIN(a->base.se_rssi, STA_RSSI_MAX);
899 rssib = MIN(b->base.se_rssi, STA_RSSI_MAX);
900 if (abs(rssib - rssia) < 5) {
901 /* best/max rate preferred if signal level close enough XXX */
902 maxa = maxrate(&a->base);
903 maxb = maxrate(&b->base);
904 if (maxa != maxb)
905 return maxa - maxb;
906 /* XXX use freq for channel preference */
907 /* for now just prefer 5Ghz band to all other bands */
908 PREFER(IEEE80211_IS_CHAN_5GHZ(a->base.se_chan),
909 IEEE80211_IS_CHAN_5GHZ(b->base.se_chan), 1);
910 }
911 /* all things being equal, use signal level */
912 return a->base.se_rssi - b->base.se_rssi;
913 #undef PREFER
914 }
915
916 /*
917 * Check rate set suitability and return the best supported rate.
918 * XXX inspect MCS for HT
919 */
920 static int
921 check_rate(struct ieee80211vap *vap, const struct ieee80211_channel *chan,
922 const struct ieee80211_scan_entry *se)
923 {
924 const struct ieee80211_rateset *srs;
925 int i, j, nrs, r, okrate, badrate, fixedrate, ucastrate;
926 const uint8_t *rs;
927
928 okrate = badrate = 0;
929
930 srs = ieee80211_get_suprates(vap->iv_ic, chan);
931 nrs = se->se_rates[1];
932 rs = se->se_rates+2;
933 /* XXX MCS */
934 ucastrate = vap->iv_txparms[ieee80211_chan2mode(chan)].ucastrate;
935 fixedrate = IEEE80211_FIXED_RATE_NONE;
936 again:
937 for (i = 0; i < nrs; i++) {
938 r = IEEE80211_RV(rs[i]);
939 badrate = r;
940 /*
941 * Check any fixed rate is included.
942 */
943 if (r == ucastrate)
944 fixedrate = r;
945 /*
946 * Check against our supported rates.
947 */
948 for (j = 0; j < srs->rs_nrates; j++)
949 if (r == IEEE80211_RV(srs->rs_rates[j])) {
950 if (r > okrate) /* NB: track max */
951 okrate = r;
952 break;
953 }
954
955 if (j == srs->rs_nrates && (rs[i] & IEEE80211_RATE_BASIC)) {
956 /*
957 * Don't try joining a BSS, if we don't support
958 * one of its basic rates.
959 */
960 okrate = 0;
961 goto back;
962 }
963 }
964 if (rs == se->se_rates+2) {
965 /* scan xrates too; sort of an algol68-style for loop */
966 nrs = se->se_xrates[1];
967 rs = se->se_xrates+2;
968 goto again;
969 }
970
971 back:
972 if (okrate == 0 || ucastrate != fixedrate)
973 return badrate | IEEE80211_RATE_BASIC;
974 else
975 return IEEE80211_RV(okrate);
976 }
977
978 static __inline int
979 match_id(const uint8_t *ie, const uint8_t *val, int len)
980 {
981 return (ie[1] == len && memcmp(ie+2, val, len) == 0);
982 }
983
984 static int
985 match_ssid(const uint8_t *ie,
986 int nssid, const struct ieee80211_scan_ssid ssids[])
987 {
988 int i;
989
990 for (i = 0; i < nssid; i++) {
991 if (match_id(ie, ssids[i].ssid, ssids[i].len))
992 return 1;
993 }
994 return 0;
995 }
996
997 #ifdef IEEE80211_SUPPORT_TDMA
998 static int
999 tdma_isfull(const struct ieee80211_tdma_param *tdma)
1000 {
1001 int slot, slotcnt;
1002
1003 slotcnt = tdma->tdma_slotcnt;
1004 for (slot = slotcnt-1; slot >= 0; slot--)
1005 if (isclr(tdma->tdma_inuse, slot))
1006 return 0;
1007 return 1;
1008 }
1009 #endif /* IEEE80211_SUPPORT_TDMA */
1010
1011 /*
1012 * Test a scan candidate for suitability/compatibility.
1013 */
1014 static int
1015 match_bss(struct ieee80211vap *vap,
1016 const struct ieee80211_scan_state *ss, struct sta_entry *se0,
1017 int debug)
1018 {
1019 struct ieee80211com *ic = vap->iv_ic;
1020 struct ieee80211_scan_entry *se = &se0->base;
1021 uint8_t rate;
1022 int fail;
1023
1024 fail = 0;
1025 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, se->se_chan)))
1026 fail |= MATCH_CHANNEL;
1027 /*
1028 * NB: normally the desired mode is used to construct
1029 * the channel list, but it's possible for the scan
1030 * cache to include entries for stations outside this
1031 * list so we check the desired mode here to weed them
1032 * out.
1033 */
1034 if (vap->iv_des_mode != IEEE80211_MODE_AUTO &&
1035 (se->se_chan->ic_flags & IEEE80211_CHAN_ALLTURBO) !=
1036 chanflags[vap->iv_des_mode])
1037 fail |= MATCH_CHANNEL;
1038 if (vap->iv_opmode == IEEE80211_M_IBSS) {
1039 if ((se->se_capinfo & IEEE80211_CAPINFO_IBSS) == 0)
1040 fail |= MATCH_CAPINFO;
1041 #ifdef IEEE80211_SUPPORT_TDMA
1042 } else if (vap->iv_opmode == IEEE80211_M_AHDEMO) {
1043 /*
1044 * Adhoc demo network setup shouldn't really be scanning
1045 * but just in case skip stations operating in IBSS or
1046 * BSS mode.
1047 */
1048 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS))
1049 fail |= MATCH_CAPINFO;
1050 /*
1051 * TDMA operation cannot coexist with a normal 802.11 network;
1052 * skip if IBSS or ESS capabilities are marked and require
1053 * the beacon have a TDMA ie present.
1054 */
1055 if (vap->iv_caps & IEEE80211_C_TDMA) {
1056 const struct ieee80211_tdma_param *tdma =
1057 (const struct ieee80211_tdma_param *)se->se_ies.tdma_ie;
1058 const struct ieee80211_tdma_state *ts = vap->iv_tdma;
1059
1060 if (tdma == NULL)
1061 fail |= MATCH_TDMA_NOIE;
1062 else if (tdma->tdma_version != ts->tdma_version)
1063 fail |= MATCH_TDMA_VERSION;
1064 else if (tdma->tdma_slot != 0)
1065 fail |= MATCH_TDMA_NOTMASTER;
1066 else if (tdma_isfull(tdma))
1067 fail |= MATCH_TDMA_NOSLOT;
1068 #if 0
1069 else if (ieee80211_local_address(se->se_macaddr))
1070 fail |= MATCH_TDMA_LOCAL;
1071 #endif
1072 }
1073 #endif /* IEEE80211_SUPPORT_TDMA */
1074 #ifdef IEEE80211_SUPPORT_MESH
1075 } else if (vap->iv_opmode == IEEE80211_M_MBSS) {
1076 const struct ieee80211_mesh_state *ms = vap->iv_mesh;
1077 /*
1078 * Mesh nodes have IBSS & ESS bits in capinfo turned off
1079 * and two special ie's that must be present.
1080 */
1081 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS))
1082 fail |= MATCH_CAPINFO;
1083 else if (se->se_meshid[0] != IEEE80211_ELEMID_MESHID)
1084 fail |= MATCH_MESH_NOID;
1085 else if (ms->ms_idlen != 0 &&
1086 match_id(se->se_meshid, ms->ms_id, ms->ms_idlen))
1087 fail |= MATCH_MESHID;
1088 #endif
1089 } else {
1090 if ((se->se_capinfo & IEEE80211_CAPINFO_ESS) == 0)
1091 fail |= MATCH_CAPINFO;
1092 /*
1093 * If 11d is enabled and we're attempting to join a bss
1094 * that advertises it's country code then compare our
1095 * current settings to what we fetched from the country ie.
1096 * If our country code is unspecified or different then do
1097 * not attempt to join the bss. We should have already
1098 * dispatched an event to user space that identifies the
1099 * new country code so our regdomain config should match.
1100 */
1101 if ((IEEE80211_IS_CHAN_11D(se->se_chan) ||
1102 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) &&
1103 se->se_cc[0] != 0 &&
1104 (ic->ic_regdomain.country == CTRY_DEFAULT ||
1105 !isocmp(se->se_cc, ic->ic_regdomain.isocc)))
1106 fail |= MATCH_CC;
1107 }
1108 if (vap->iv_flags & IEEE80211_F_PRIVACY) {
1109 if ((se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0)
1110 fail |= MATCH_PRIVACY;
1111 } else {
1112 /* XXX does this mean privacy is supported or required? */
1113 if (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY)
1114 fail |= MATCH_PRIVACY;
1115 }
1116 se0->se_flags &= ~STA_DEMOTE11B;
1117 rate = check_rate(vap, se->se_chan, se);
1118 if (rate & IEEE80211_RATE_BASIC) {
1119 fail |= MATCH_RATE;
1120 /*
1121 * An 11b-only ap will give a rate mismatch if there is an
1122 * OFDM fixed tx rate for 11g. Try downgrading the channel
1123 * in the scan list to 11b and retry the rate check.
1124 */
1125 if (IEEE80211_IS_CHAN_ANYG(se->se_chan)) {
1126 rate = check_rate(vap, demote11b(vap, se->se_chan), se);
1127 if ((rate & IEEE80211_RATE_BASIC) == 0) {
1128 fail &= ~MATCH_RATE;
1129 se0->se_flags |= STA_DEMOTE11B;
1130 }
1131 }
1132 } else if (rate < 2*24) {
1133 /*
1134 * This is an 11b-only ap. Check the desired mode in
1135 * case that needs to be honored (mode 11g filters out
1136 * 11b-only ap's). Otherwise force any 11g channel used
1137 * in scanning to be demoted.
1138 *
1139 * NB: we cheat a bit here by looking at the max rate;
1140 * we could/should check the rates.
1141 */
1142 if (!(vap->iv_des_mode == IEEE80211_MODE_AUTO ||
1143 vap->iv_des_mode == IEEE80211_MODE_11B))
1144 fail |= MATCH_RATE;
1145 else
1146 se0->se_flags |= STA_DEMOTE11B;
1147 }
1148 if (ss->ss_nssid != 0 &&
1149 !match_ssid(se->se_ssid, ss->ss_nssid, ss->ss_ssid))
1150 fail |= MATCH_SSID;
1151 if ((vap->iv_flags & IEEE80211_F_DESBSSID) &&
1152 !IEEE80211_ADDR_EQ(vap->iv_des_bssid, se->se_bssid))
1153 fail |= MATCH_BSSID;
1154 if (se0->se_fails >= STA_FAILS_MAX)
1155 fail |= MATCH_FAILS;
1156 if (se0->se_notseen >= STA_PURGE_SCANS)
1157 fail |= MATCH_NOTSEEN;
1158 if (se->se_rssi < STA_RSSI_MIN)
1159 fail |= MATCH_RSSI;
1160 #ifdef IEEE80211_DEBUG
1161 if (ieee80211_msg(vap, debug)) {
1162 printf(" %c %s",
1163 fail & MATCH_FAILS ? '=' :
1164 fail & MATCH_NOTSEEN ? '^' :
1165 fail & MATCH_CC ? '$' :
1166 #ifdef IEEE80211_SUPPORT_TDMA
1167 fail & MATCH_TDMA_NOIE ? '&' :
1168 fail & MATCH_TDMA_VERSION ? 'v' :
1169 fail & MATCH_TDMA_NOTMASTER ? 's' :
1170 fail & MATCH_TDMA_NOSLOT ? 'f' :
1171 fail & MATCH_TDMA_LOCAL ? 'l' :
1172 #endif
1173 fail & MATCH_MESH_NOID ? 'm' :
1174 fail ? '-' : '+', ether_sprintf(se->se_macaddr));
1175 printf(" %s%c", ether_sprintf(se->se_bssid),
1176 fail & MATCH_BSSID ? '!' : ' ');
1177 printf(" %3d%c", ieee80211_chan2ieee(ic, se->se_chan),
1178 fail & MATCH_CHANNEL ? '!' : ' ');
1179 printf(" %+4d%c", se->se_rssi, fail & MATCH_RSSI ? '!' : ' ');
1180 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2,
1181 fail & MATCH_RATE ? '!' : ' ');
1182 printf(" %4s%c",
1183 (se->se_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" :
1184 (se->se_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : "",
1185 fail & MATCH_CAPINFO ? '!' : ' ');
1186 printf(" %3s%c ",
1187 (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) ?
1188 "wep" : "no",
1189 fail & MATCH_PRIVACY ? '!' : ' ');
1190 ieee80211_print_essid(se->se_ssid+2, se->se_ssid[1]);
1191 printf("%s\n", fail & (MATCH_SSID | MATCH_MESHID) ? "!" : "");
1192 }
1193 #endif
1194 return fail;
1195 }
1196
1197 static void
1198 sta_update_notseen(struct sta_table *st)
1199 {
1200 struct sta_entry *se;
1201
1202 IEEE80211_SCAN_TABLE_LOCK(st);
1203 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1204 /*
1205 * If seen the reset and don't bump the count;
1206 * otherwise bump the ``not seen'' count. Note
1207 * that this insures that stations for which we
1208 * see frames while not scanning but not during
1209 * this scan will not be penalized.
1210 */
1211 if (se->se_seen)
1212 se->se_seen = 0;
1213 else
1214 se->se_notseen++;
1215 }
1216 IEEE80211_SCAN_TABLE_UNLOCK(st);
1217 }
1218
1219 static void
1220 sta_dec_fails(struct sta_table *st)
1221 {
1222 struct sta_entry *se;
1223
1224 IEEE80211_SCAN_TABLE_LOCK(st);
1225 TAILQ_FOREACH(se, &st->st_entry, se_list)
1226 if (se->se_fails)
1227 se->se_fails--;
1228 IEEE80211_SCAN_TABLE_UNLOCK(st);
1229 }
1230
1231 static struct sta_entry *
1232 select_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, int debug)
1233 {
1234 struct sta_table *st = ss->ss_priv;
1235 struct sta_entry *se, *selbs = NULL;
1236
1237 IEEE80211_DPRINTF(vap, debug, " %s\n",
1238 "macaddr bssid chan rssi rate flag wep essid");
1239 IEEE80211_SCAN_TABLE_LOCK(st);
1240 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1241 ieee80211_ies_expand(&se->base.se_ies);
1242 if (match_bss(vap, ss, se, debug) == 0) {
1243 if (selbs == NULL)
1244 selbs = se;
1245 else if (sta_compare(se, selbs) > 0)
1246 selbs = se;
1247 }
1248 }
1249 IEEE80211_SCAN_TABLE_UNLOCK(st);
1250
1251 return selbs;
1252 }
1253
1254 /*
1255 * Pick an ap or ibss network to join or find a channel
1256 * to use to start an ibss network.
1257 */
1258 static int
1259 sta_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1260 {
1261 struct sta_table *st = ss->ss_priv;
1262 struct sta_entry *selbs;
1263 struct ieee80211_channel *chan;
1264
1265 KASSERT(vap->iv_opmode == IEEE80211_M_STA,
1266 ("wrong mode %u", vap->iv_opmode));
1267
1268 if (st->st_newscan) {
1269 sta_update_notseen(st);
1270 st->st_newscan = 0;
1271 }
1272 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1273 /*
1274 * Manual/background scan, don't select+join the
1275 * bss, just return. The scanning framework will
1276 * handle notification that this has completed.
1277 */
1278 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1279 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1280 "%s: nopick; return 1\n", __func__);
1281 return 1;
1282 }
1283 /*
1284 * Automatic sequencing; look for a candidate and
1285 * if found join the network.
1286 */
1287 /* NB: unlocked read should be ok */
1288 if (TAILQ_FIRST(&st->st_entry) == NULL) {
1289 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1290 "%s: no scan candidate, join=%d, return 0\n",
1291 __func__,
1292 !! (ss->ss_flags & IEEE80211_SCAN_NOJOIN));
1293 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1294 return 0;
1295 notfound:
1296 /*
1297 * If nothing suitable was found decrement
1298 * the failure counts so entries will be
1299 * reconsidered the next time around. We
1300 * really want to do this only for sta's
1301 * where we've previously had some success.
1302 */
1303 sta_dec_fails(st);
1304 st->st_newscan = 1;
1305 return 0; /* restart scan */
1306 }
1307 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1308 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1309 return (selbs != NULL);
1310 if (selbs == NULL)
1311 goto notfound;
1312 chan = selbs->base.se_chan;
1313 if (selbs->se_flags & STA_DEMOTE11B)
1314 chan = demote11b(vap, chan);
1315 if (!ieee80211_sta_join(vap, chan, &selbs->base))
1316 goto notfound;
1317 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1318 "%s: terminate scan; return 1\n", __func__);
1319 return 1; /* terminate scan */
1320 }
1321
1322 /*
1323 * Lookup an entry in the scan cache. We assume we're
1324 * called from the bottom half or such that we don't need
1325 * to block the bottom half so that it's safe to return
1326 * a reference to an entry w/o holding the lock on the table.
1327 */
1328 static struct sta_entry *
1329 sta_lookup(struct sta_table *st, const uint8_t macaddr[IEEE80211_ADDR_LEN])
1330 {
1331 struct sta_entry *se;
1332 int hash = STA_HASH(macaddr);
1333
1334 IEEE80211_SCAN_TABLE_LOCK(st);
1335 LIST_FOREACH(se, &st->st_hash[hash], se_hash)
1336 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr))
1337 break;
1338 IEEE80211_SCAN_TABLE_UNLOCK(st);
1339
1340 return se; /* NB: unlocked */
1341 }
1342
1343 static void
1344 sta_roam_check(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1345 {
1346 struct ieee80211com *ic = vap->iv_ic;
1347 struct ieee80211_node *ni = vap->iv_bss;
1348 struct sta_table *st = ss->ss_priv;
1349 enum ieee80211_phymode mode;
1350 struct sta_entry *se, *selbs;
1351 uint8_t roamRate, curRate, ucastRate;
1352 int8_t roamRssi, curRssi;
1353
1354 se = sta_lookup(st, ni->ni_macaddr);
1355 if (se == NULL) {
1356 /* XXX something is wrong */
1357 return;
1358 }
1359
1360 mode = ieee80211_chan2mode(ic->ic_bsschan);
1361 roamRate = vap->iv_roamparms[mode].rate;
1362 roamRssi = vap->iv_roamparms[mode].rssi;
1363 KASSERT(roamRate != 0 && roamRssi != 0, ("iv_roamparms are not"
1364 "initialized for %s mode!", ieee80211_phymode_name[mode]));
1365
1366 ucastRate = vap->iv_txparms[mode].ucastrate;
1367 /* NB: the most up to date rssi is in the node, not the scan cache */
1368 curRssi = ic->ic_node_getrssi(ni);
1369 if (ucastRate == IEEE80211_FIXED_RATE_NONE) {
1370 curRate = ni->ni_txrate;
1371 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM,
1372 "%s: currssi %d currate %u roamrssi %d roamrate %u\n",
1373 __func__, curRssi, curRate, roamRssi, roamRate);
1374 } else {
1375 curRate = roamRate; /* NB: insure compare below fails */
1376 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM,
1377 "%s: currssi %d roamrssi %d\n", __func__, curRssi, roamRssi);
1378 }
1379 /*
1380 * Check if a new ap should be used and switch.
1381 * XXX deauth current ap
1382 */
1383 if (curRate < roamRate || curRssi < roamRssi) {
1384 if (ieee80211_time_after(ticks, ic->ic_lastscan + vap->iv_scanvalid)) {
1385 /*
1386 * Scan cache contents are too old; force a scan now
1387 * if possible so we have current state to make a
1388 * decision with. We don't kick off a bg scan if
1389 * we're using dynamic turbo and boosted or if the
1390 * channel is busy.
1391 * XXX force immediate switch on scan complete
1392 */
1393 if (!IEEE80211_IS_CHAN_DTURBO(ic->ic_curchan) &&
1394 ((vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) ||
1395 ieee80211_time_after(ticks, ic->ic_lastdata + vap->iv_bgscanidle)))
1396 ieee80211_bg_scan(vap, 0);
1397 return;
1398 }
1399 se->base.se_rssi = curRssi;
1400 selbs = select_bss(ss, vap, IEEE80211_MSG_ROAM);
1401 if (selbs != NULL && selbs != se) {
1402 struct ieee80211_channel *chan;
1403
1404 IEEE80211_DPRINTF(vap,
1405 IEEE80211_MSG_ROAM | IEEE80211_MSG_DEBUG,
1406 "%s: ROAM: curRate %u, roamRate %u, "
1407 "curRssi %d, roamRssi %d\n", __func__,
1408 curRate, roamRate, curRssi, roamRssi);
1409
1410 chan = selbs->base.se_chan;
1411 if (selbs->se_flags & STA_DEMOTE11B)
1412 chan = demote11b(vap, chan);
1413 (void) ieee80211_sta_join(vap, chan, &selbs->base);
1414 }
1415 }
1416 }
1417
1418 /*
1419 * Age entries in the scan cache.
1420 * XXX also do roaming since it's convenient
1421 */
1422 static void
1423 sta_age(struct ieee80211_scan_state *ss)
1424 {
1425 struct ieee80211vap *vap = ss->ss_vap;
1426
1427 adhoc_age(ss);
1428 /*
1429 * If rate control is enabled check periodically to see if
1430 * we should roam from our current connection to one that
1431 * might be better. This only applies when we're operating
1432 * in sta mode and automatic roaming is set.
1433 * XXX defer if busy
1434 * XXX repeater station
1435 * XXX do when !bgscan?
1436 */
1437 KASSERT(vap->iv_opmode == IEEE80211_M_STA,
1438 ("wrong mode %u", vap->iv_opmode));
1439 if (vap->iv_roaming == IEEE80211_ROAMING_AUTO &&
1440 (vap->iv_flags & IEEE80211_F_BGSCAN) &&
1441 vap->iv_state >= IEEE80211_S_RUN)
1442 /* XXX vap is implicit */
1443 sta_roam_check(ss, vap);
1444 }
1445
1446 /*
1447 * Iterate over the entries in the scan cache, invoking
1448 * the callback function on each one.
1449 */
1450 static void
1451 sta_iterate(struct ieee80211_scan_state *ss,
1452 ieee80211_scan_iter_func *f, void *arg)
1453 {
1454 struct sta_table *st = ss->ss_priv;
1455 struct sta_entry *se;
1456 u_int gen;
1457
1458 IEEE80211_SCAN_ITER_LOCK(st);
1459 gen = st->st_scaniter++;
1460 restart:
1461 IEEE80211_SCAN_TABLE_LOCK(st);
1462 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1463 if (se->se_scangen != gen) {
1464 se->se_scangen = gen;
1465 /* update public state */
1466 se->base.se_age = ticks - se->se_lastupdate;
1467 IEEE80211_SCAN_TABLE_UNLOCK(st);
1468 (*f)(arg, &se->base);
1469 goto restart;
1470 }
1471 }
1472 IEEE80211_SCAN_TABLE_UNLOCK(st);
1473
1474 IEEE80211_SCAN_ITER_UNLOCK(st);
1475 }
1476
1477 static void
1478 sta_assoc_fail(struct ieee80211_scan_state *ss,
1479 const uint8_t macaddr[IEEE80211_ADDR_LEN], int reason)
1480 {
1481 struct sta_table *st = ss->ss_priv;
1482 struct sta_entry *se;
1483
1484 se = sta_lookup(st, macaddr);
1485 if (se != NULL) {
1486 se->se_fails++;
1487 se->se_lastfail = ticks;
1488 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN,
1489 macaddr, "%s: reason %u fails %u",
1490 __func__, reason, se->se_fails);
1491 }
1492 }
1493
1494 static void
1495 sta_assoc_success(struct ieee80211_scan_state *ss,
1496 const uint8_t macaddr[IEEE80211_ADDR_LEN])
1497 {
1498 struct sta_table *st = ss->ss_priv;
1499 struct sta_entry *se;
1500
1501 se = sta_lookup(st, macaddr);
1502 if (se != NULL) {
1503 #if 0
1504 se->se_fails = 0;
1505 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN,
1506 macaddr, "%s: fails %u",
1507 __func__, se->se_fails);
1508 #endif
1509 se->se_lastassoc = ticks;
1510 }
1511 }
1512
1513 static const struct ieee80211_scanner sta_default = {
1514 .scan_name = "default",
1515 .scan_attach = sta_attach,
1516 .scan_detach = sta_detach,
1517 .scan_start = sta_start,
1518 .scan_restart = sta_restart,
1519 .scan_cancel = sta_cancel,
1520 .scan_end = sta_pick_bss,
1521 .scan_flush = sta_flush,
1522 .scan_add = sta_add,
1523 .scan_age = sta_age,
1524 .scan_iterate = sta_iterate,
1525 .scan_assoc_fail = sta_assoc_fail,
1526 .scan_assoc_success = sta_assoc_success,
1527 };
1528 IEEE80211_SCANNER_ALG(sta, IEEE80211_M_STA, sta_default);
1529
1530 /*
1531 * Adhoc mode-specific support.
1532 */
1533
1534 static const uint16_t adhocWorld[] = /* 36, 40, 44, 48 */
1535 { 5180, 5200, 5220, 5240 };
1536 static const uint16_t adhocFcc3[] = /* 36, 40, 44, 48 145, 149, 153, 157, 161, 165 */
1537 { 5180, 5200, 5220, 5240, 5725, 5745, 5765, 5785, 5805, 5825 };
1538 static const uint16_t adhocMkk[] = /* 34, 38, 42, 46 */
1539 { 5170, 5190, 5210, 5230 };
1540 static const uint16_t adhoc11b[] = /* 10, 11 */
1541 { 2457, 2462 };
1542
1543 static const struct scanlist adhocScanTable[] = {
1544 { IEEE80211_MODE_11B, X(adhoc11b) },
1545 { IEEE80211_MODE_11A, X(adhocWorld) },
1546 { IEEE80211_MODE_11A, X(adhocFcc3) },
1547 { IEEE80211_MODE_11B, X(adhocMkk) },
1548 { .list = NULL }
1549 };
1550 #undef X
1551
1552 /*
1553 * Start an adhoc-mode scan by populating the channel list.
1554 */
1555 static int
1556 adhoc_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1557 {
1558 struct sta_table *st = ss->ss_priv;
1559
1560 makescanlist(ss, vap, adhocScanTable);
1561
1562 if (ss->ss_mindwell == 0)
1563 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */
1564 if (ss->ss_maxdwell == 0)
1565 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
1566
1567 st->st_scangen++;
1568 st->st_newscan = 1;
1569
1570 return 0;
1571 }
1572
1573 /*
1574 * Select a channel to start an adhoc network on.
1575 * The channel list was populated with appropriate
1576 * channels so select one that looks least occupied.
1577 */
1578 static struct ieee80211_channel *
1579 adhoc_pick_channel(struct ieee80211_scan_state *ss, int flags)
1580 {
1581 struct sta_table *st = ss->ss_priv;
1582 struct sta_entry *se;
1583 struct ieee80211_channel *c, *bestchan;
1584 int i, bestrssi, maxrssi;
1585
1586 bestchan = NULL;
1587 bestrssi = -1;
1588
1589 IEEE80211_SCAN_TABLE_LOCK(st);
1590 for (i = 0; i < ss->ss_last; i++) {
1591 c = ss->ss_chans[i];
1592 /* never consider a channel with radar */
1593 if (IEEE80211_IS_CHAN_RADAR(c))
1594 continue;
1595 /* skip channels disallowed by regulatory settings */
1596 if (IEEE80211_IS_CHAN_NOADHOC(c))
1597 continue;
1598 /* check channel attributes for band compatibility */
1599 if (flags != 0 && (c->ic_flags & flags) != flags)
1600 continue;
1601 maxrssi = 0;
1602 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1603 if (se->base.se_chan != c)
1604 continue;
1605 if (se->base.se_rssi > maxrssi)
1606 maxrssi = se->base.se_rssi;
1607 }
1608 if (bestchan == NULL || maxrssi < bestrssi)
1609 bestchan = c;
1610 }
1611 IEEE80211_SCAN_TABLE_UNLOCK(st);
1612
1613 return bestchan;
1614 }
1615
1616 /*
1617 * Pick an ibss network to join or find a channel
1618 * to use to start an ibss network.
1619 */
1620 static int
1621 adhoc_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1622 {
1623 struct sta_table *st = ss->ss_priv;
1624 struct sta_entry *selbs;
1625 struct ieee80211_channel *chan;
1626 struct ieee80211com *ic = vap->iv_ic;
1627
1628 KASSERT(vap->iv_opmode == IEEE80211_M_IBSS ||
1629 vap->iv_opmode == IEEE80211_M_AHDEMO ||
1630 vap->iv_opmode == IEEE80211_M_MBSS,
1631 ("wrong opmode %u", vap->iv_opmode));
1632
1633 if (st->st_newscan) {
1634 sta_update_notseen(st);
1635 st->st_newscan = 0;
1636 }
1637 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1638 /*
1639 * Manual/background scan, don't select+join the
1640 * bss, just return. The scanning framework will
1641 * handle notification that this has completed.
1642 */
1643 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1644 return 1;
1645 }
1646 /*
1647 * Automatic sequencing; look for a candidate and
1648 * if found join the network.
1649 */
1650 /* NB: unlocked read should be ok */
1651 if (TAILQ_FIRST(&st->st_entry) == NULL) {
1652 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1653 "%s: no scan candidate\n", __func__);
1654 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1655 return 0;
1656 notfound:
1657 /* NB: never auto-start a tdma network for slot !0 */
1658 #ifdef IEEE80211_SUPPORT_TDMA
1659 if (vap->iv_des_nssid &&
1660 ((vap->iv_caps & IEEE80211_C_TDMA) == 0 ||
1661 ieee80211_tdma_getslot(vap) == 0)) {
1662 #else
1663 if (vap->iv_des_nssid) {
1664 #endif
1665 /*
1666 * No existing adhoc network to join and we have
1667 * an ssid; start one up. If no channel was
1668 * specified, try to select a channel.
1669 */
1670 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC ||
1671 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
1672 chan = adhoc_pick_channel(ss, 0);
1673 } else
1674 chan = vap->iv_des_chan;
1675 if (chan != NULL) {
1676 /*
1677 * Create a HT capable IBSS; the per-node
1678 * probe request/response will result in
1679 * "correct" rate control capabilities being
1680 * negotiated.
1681 */
1682 chan = ieee80211_ht_adjust_channel(ic,
1683 chan, vap->iv_flags_ht);
1684 chan = ieee80211_vht_adjust_channel(ic,
1685 chan, vap->iv_flags_vht);
1686 ieee80211_create_ibss(vap, chan);
1687 return 1;
1688 }
1689 }
1690 /*
1691 * If nothing suitable was found decrement
1692 * the failure counts so entries will be
1693 * reconsidered the next time around. We
1694 * really want to do this only for sta's
1695 * where we've previously had some success.
1696 */
1697 sta_dec_fails(st);
1698 st->st_newscan = 1;
1699 return 0; /* restart scan */
1700 }
1701 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1702 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1703 return (selbs != NULL);
1704 if (selbs == NULL)
1705 goto notfound;
1706 chan = selbs->base.se_chan;
1707 if (selbs->se_flags & STA_DEMOTE11B)
1708 chan = demote11b(vap, chan);
1709 /*
1710 * If HT is available, make it a possibility here.
1711 * The intent is to enable HT20/HT40 when joining a non-HT
1712 * IBSS node; we can then advertise HT IEs and speak HT
1713 * to any subsequent nodes that support it.
1714 */
1715 chan = ieee80211_ht_adjust_channel(ic,
1716 chan, vap->iv_flags_ht);
1717 chan = ieee80211_vht_adjust_channel(ic,
1718 chan, vap->iv_flags_vht);
1719 if (!ieee80211_sta_join(vap, chan, &selbs->base))
1720 goto notfound;
1721 return 1; /* terminate scan */
1722 }
1723
1724 /*
1725 * Age entries in the scan cache.
1726 */
1727 static void
1728 adhoc_age(struct ieee80211_scan_state *ss)
1729 {
1730 struct sta_table *st = ss->ss_priv;
1731 struct sta_entry *se, *next;
1732
1733 IEEE80211_SCAN_TABLE_LOCK(st);
1734 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) {
1735 if (se->se_notseen > STA_PURGE_SCANS) {
1736 TAILQ_REMOVE(&st->st_entry, se, se_list);
1737 LIST_REMOVE(se, se_hash);
1738 ieee80211_ies_cleanup(&se->base.se_ies);
1739 IEEE80211_FREE(se, M_80211_SCAN);
1740 }
1741 }
1742 IEEE80211_SCAN_TABLE_UNLOCK(st);
1743 }
1744
1745 static const struct ieee80211_scanner adhoc_default = {
1746 .scan_name = "default",
1747 .scan_attach = sta_attach,
1748 .scan_detach = sta_detach,
1749 .scan_start = adhoc_start,
1750 .scan_restart = sta_restart,
1751 .scan_cancel = sta_cancel,
1752 .scan_end = adhoc_pick_bss,
1753 .scan_flush = sta_flush,
1754 .scan_pickchan = adhoc_pick_channel,
1755 .scan_add = sta_add,
1756 .scan_age = adhoc_age,
1757 .scan_iterate = sta_iterate,
1758 .scan_assoc_fail = sta_assoc_fail,
1759 .scan_assoc_success = sta_assoc_success,
1760 };
1761 IEEE80211_SCANNER_ALG(ibss, IEEE80211_M_IBSS, adhoc_default);
1762 IEEE80211_SCANNER_ALG(ahdemo, IEEE80211_M_AHDEMO, adhoc_default);
1763
1764 static int
1765 ap_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1766 {
1767 struct sta_table *st = ss->ss_priv;
1768
1769 makescanlist(ss, vap, staScanTable);
1770
1771 if (ss->ss_mindwell == 0)
1772 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */
1773 if (ss->ss_maxdwell == 0)
1774 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
1775
1776 st->st_scangen++;
1777 st->st_newscan = 1;
1778
1779 return 0;
1780 }
1781
1782 /*
1783 * Cancel an ongoing scan.
1784 */
1785 static int
1786 ap_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1787 {
1788 return 0;
1789 }
1790
1791 /*
1792 * Pick a quiet channel to use for ap operation.
1793 */
1794 static struct ieee80211_channel *
1795 ap_pick_channel(struct ieee80211_scan_state *ss, int flags)
1796 {
1797 struct sta_table *st = ss->ss_priv;
1798 struct ieee80211_channel *bestchan = NULL;
1799 int i;
1800
1801 /* XXX select channel more intelligently, e.g. channel spread, power */
1802 /* NB: use scan list order to preserve channel preference */
1803 for (i = 0; i < ss->ss_last; i++) {
1804 struct ieee80211_channel *chan = ss->ss_chans[i];
1805 /*
1806 * If the channel is unoccupied the max rssi
1807 * should be zero; just take it. Otherwise
1808 * track the channel with the lowest rssi and
1809 * use that when all channels appear occupied.
1810 */
1811 if (IEEE80211_IS_CHAN_RADAR(chan))
1812 continue;
1813 if (IEEE80211_IS_CHAN_NOHOSTAP(chan))
1814 continue;
1815 /* check channel attributes for band compatibility */
1816 if (flags != 0 && (chan->ic_flags & flags) != flags)
1817 continue;
1818 KASSERT(sizeof(chan->ic_ieee) == 1, ("ic_chan size"));
1819 /* XXX channel have interference */
1820 if (st->st_maxrssi[chan->ic_ieee] == 0) {
1821 /* XXX use other considerations */
1822 return chan;
1823 }
1824 if (bestchan == NULL ||
1825 st->st_maxrssi[chan->ic_ieee] < st->st_maxrssi[bestchan->ic_ieee])
1826 bestchan = chan;
1827 }
1828 return bestchan;
1829 }
1830
1831 /*
1832 * Pick a quiet channel to use for ap operation.
1833 */
1834 static int
1835 ap_end(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1836 {
1837 struct ieee80211com *ic = vap->iv_ic;
1838 struct ieee80211_channel *bestchan, *chan;
1839
1840 KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP,
1841 ("wrong opmode %u", vap->iv_opmode));
1842 bestchan = ap_pick_channel(ss, 0);
1843 if (bestchan == NULL) {
1844 /* no suitable channel, should not happen */
1845 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1846 "%s: no suitable channel! (should not happen)\n", __func__);
1847 /* XXX print something? */
1848 return 0; /* restart scan */
1849 }
1850 /*
1851 * If this is a dynamic turbo channel, start with the unboosted one.
1852 */
1853 if (IEEE80211_IS_CHAN_TURBO(bestchan)) {
1854 bestchan = ieee80211_find_channel(ic, bestchan->ic_freq,
1855 bestchan->ic_flags & ~IEEE80211_CHAN_TURBO);
1856 if (bestchan == NULL) {
1857 /* should never happen ?? */
1858 return 0;
1859 }
1860 }
1861 if (ss->ss_flags & (IEEE80211_SCAN_NOPICK | IEEE80211_SCAN_NOJOIN)) {
1862 /*
1863 * Manual/background scan, don't select+join the
1864 * bss, just return. The scanning framework will
1865 * handle notification that this has completed.
1866 */
1867 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1868 return 1;
1869 }
1870 chan = ieee80211_ht_adjust_channel(ic, bestchan, vap->iv_flags_ht);
1871 chan = ieee80211_vht_adjust_channel(ic, chan, vap->iv_flags_vht);
1872 ieee80211_create_ibss(vap, chan);
1873
1874 return 1;
1875 }
1876
1877 static const struct ieee80211_scanner ap_default = {
1878 .scan_name = "default",
1879 .scan_attach = sta_attach,
1880 .scan_detach = sta_detach,
1881 .scan_start = ap_start,
1882 .scan_restart = sta_restart,
1883 .scan_cancel = ap_cancel,
1884 .scan_end = ap_end,
1885 .scan_flush = sta_flush,
1886 .scan_pickchan = ap_pick_channel,
1887 .scan_add = sta_add,
1888 .scan_age = adhoc_age,
1889 .scan_iterate = sta_iterate,
1890 .scan_assoc_success = sta_assoc_success,
1891 .scan_assoc_fail = sta_assoc_fail,
1892 };
1893 IEEE80211_SCANNER_ALG(ap, IEEE80211_M_HOSTAP, ap_default);
1894
1895 #ifdef IEEE80211_SUPPORT_MESH
1896 /*
1897 * Pick an mbss network to join or find a channel
1898 * to use to start an mbss network.
1899 */
1900 static int
1901 mesh_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1902 {
1903 struct sta_table *st = ss->ss_priv;
1904 struct ieee80211_mesh_state *ms = vap->iv_mesh;
1905 struct sta_entry *selbs;
1906 struct ieee80211_channel *chan;
1907
1908 KASSERT(vap->iv_opmode == IEEE80211_M_MBSS,
1909 ("wrong opmode %u", vap->iv_opmode));
1910
1911 if (st->st_newscan) {
1912 sta_update_notseen(st);
1913 st->st_newscan = 0;
1914 }
1915 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1916 /*
1917 * Manual/background scan, don't select+join the
1918 * bss, just return. The scanning framework will
1919 * handle notification that this has completed.
1920 */
1921 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1922 return 1;
1923 }
1924 /*
1925 * Automatic sequencing; look for a candidate and
1926 * if found join the network.
1927 */
1928 /* NB: unlocked read should be ok */
1929 if (TAILQ_FIRST(&st->st_entry) == NULL) {
1930 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1931 "%s: no scan candidate\n", __func__);
1932 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1933 return 0;
1934 notfound:
1935 if (ms->ms_idlen != 0) {
1936 /*
1937 * No existing mbss network to join and we have
1938 * a meshid; start one up. If no channel was
1939 * specified, try to select a channel.
1940 */
1941 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC ||
1942 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
1943 struct ieee80211com *ic = vap->iv_ic;
1944
1945 /* XXX VHT */
1946 chan = adhoc_pick_channel(ss, 0);
1947 if (chan != NULL) {
1948 chan = ieee80211_ht_adjust_channel(ic,
1949 chan, vap->iv_flags_ht);
1950 chan = ieee80211_vht_adjust_channel(ic,
1951 chan, vap->iv_flags_vht);
1952 }
1953 } else
1954 chan = vap->iv_des_chan;
1955 if (chan != NULL) {
1956 ieee80211_create_ibss(vap, chan);
1957 return 1;
1958 }
1959 }
1960 /*
1961 * If nothing suitable was found decrement
1962 * the failure counts so entries will be
1963 * reconsidered the next time around. We
1964 * really want to do this only for sta's
1965 * where we've previously had some success.
1966 */
1967 sta_dec_fails(st);
1968 st->st_newscan = 1;
1969 return 0; /* restart scan */
1970 }
1971 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1972 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1973 return (selbs != NULL);
1974 if (selbs == NULL)
1975 goto notfound;
1976 chan = selbs->base.se_chan;
1977 if (selbs->se_flags & STA_DEMOTE11B)
1978 chan = demote11b(vap, chan);
1979 if (!ieee80211_sta_join(vap, chan, &selbs->base))
1980 goto notfound;
1981 return 1; /* terminate scan */
1982 }
1983
1984 static const struct ieee80211_scanner mesh_default = {
1985 .scan_name = "default",
1986 .scan_attach = sta_attach,
1987 .scan_detach = sta_detach,
1988 .scan_start = adhoc_start,
1989 .scan_restart = sta_restart,
1990 .scan_cancel = sta_cancel,
1991 .scan_end = mesh_pick_bss,
1992 .scan_flush = sta_flush,
1993 .scan_pickchan = adhoc_pick_channel,
1994 .scan_add = sta_add,
1995 .scan_age = adhoc_age,
1996 .scan_iterate = sta_iterate,
1997 .scan_assoc_fail = sta_assoc_fail,
1998 .scan_assoc_success = sta_assoc_success,
1999 };
2000 IEEE80211_SCANNER_ALG(mesh, IEEE80211_M_MBSS, mesh_default);
2001 #endif /* IEEE80211_SUPPORT_MESH */
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