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: releng/12.0/sys/net80211/ieee80211_scan_sta.c 327231 2017-12-27 03:23:21Z eadler $");
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 };
476
477 static void
478 add_channels(struct ieee80211vap *vap,
479 struct ieee80211_scan_state *ss,
480 enum ieee80211_phymode mode, const uint16_t freq[], int nfreq)
481 {
482 struct ieee80211com *ic = vap->iv_ic;
483 struct ieee80211_channel *c, *cg;
484 u_int modeflags;
485 int i;
486
487 KASSERT(mode < nitems(chanflags), ("Unexpected mode %u", mode));
488 modeflags = chanflags[mode];
489 for (i = 0; i < nfreq; i++) {
490 if (ss->ss_last >= IEEE80211_SCAN_MAX)
491 break;
492
493 c = ieee80211_find_channel(ic, freq[i], modeflags);
494 if (c == NULL || isexcluded(vap, c))
495 continue;
496 if (mode == IEEE80211_MODE_AUTO) {
497 /*
498 * XXX special-case 11b/g channels so we select
499 * the g channel if both are present.
500 */
501 if (IEEE80211_IS_CHAN_B(c) &&
502 (cg = find11gchannel(ic, i, c->ic_freq)) != NULL)
503 c = cg;
504 }
505 ss->ss_chans[ss->ss_last++] = c;
506 }
507 }
508
509 struct scanlist {
510 uint16_t mode;
511 uint16_t count;
512 const uint16_t *list;
513 };
514
515 static int
516 checktable(const struct scanlist *scan, const struct ieee80211_channel *c)
517 {
518 int i;
519
520 for (; scan->list != NULL; scan++) {
521 for (i = 0; i < scan->count; i++)
522 if (scan->list[i] == c->ic_freq)
523 return 1;
524 }
525 return 0;
526 }
527
528 static int
529 onscanlist(const struct ieee80211_scan_state *ss,
530 const struct ieee80211_channel *c)
531 {
532 int i;
533
534 for (i = 0; i < ss->ss_last; i++)
535 if (ss->ss_chans[i] == c)
536 return 1;
537 return 0;
538 }
539
540 static void
541 sweepchannels(struct ieee80211_scan_state *ss, struct ieee80211vap *vap,
542 const struct scanlist table[])
543 {
544 struct ieee80211com *ic = vap->iv_ic;
545 struct ieee80211_channel *c;
546 int i;
547
548 for (i = 0; i < ic->ic_nchans; i++) {
549 if (ss->ss_last >= IEEE80211_SCAN_MAX)
550 break;
551
552 c = &ic->ic_channels[i];
553 /*
554 * Ignore dynamic turbo channels; we scan them
555 * in normal mode (i.e. not boosted). Likewise
556 * for HT/VHT channels, they get scanned using
557 * legacy rates.
558 */
559 if (IEEE80211_IS_CHAN_DTURBO(c) || IEEE80211_IS_CHAN_HT(c) ||
560 IEEE80211_IS_CHAN_VHT(c))
561 continue;
562
563 /*
564 * If a desired mode was specified, scan only
565 * channels that satisfy that constraint.
566 */
567 if (vap->iv_des_mode != IEEE80211_MODE_AUTO &&
568 vap->iv_des_mode != ieee80211_chan2mode(c))
569 continue;
570
571 /*
572 * Skip channels excluded by user request.
573 */
574 if (isexcluded(vap, c))
575 continue;
576
577 /*
578 * Add the channel unless it is listed in the
579 * fixed scan order tables. This insures we
580 * don't sweep back in channels we filtered out
581 * above.
582 */
583 if (checktable(table, c))
584 continue;
585
586 /* Add channel to scanning list. */
587 ss->ss_chans[ss->ss_last++] = c;
588 }
589 /*
590 * Explicitly add any desired channel if:
591 * - not already on the scan list
592 * - allowed by any desired mode constraint
593 * - there is space in the scan list
594 * This allows the channel to be used when the filtering
595 * mechanisms would otherwise elide it (e.g HT, turbo).
596 */
597 c = vap->iv_des_chan;
598 if (c != IEEE80211_CHAN_ANYC &&
599 !onscanlist(ss, c) &&
600 (vap->iv_des_mode == IEEE80211_MODE_AUTO ||
601 vap->iv_des_mode == ieee80211_chan2mode(c)) &&
602 ss->ss_last < IEEE80211_SCAN_MAX)
603 ss->ss_chans[ss->ss_last++] = c;
604 }
605
606 static void
607 makescanlist(struct ieee80211_scan_state *ss, struct ieee80211vap *vap,
608 const struct scanlist table[])
609 {
610 const struct scanlist *scan;
611 enum ieee80211_phymode mode;
612
613 ss->ss_last = 0;
614 /*
615 * Use the table of ordered channels to construct the list
616 * of channels for scanning. Any channels in the ordered
617 * list not in the master list will be discarded.
618 */
619 for (scan = table; scan->list != NULL; scan++) {
620 mode = scan->mode;
621 if (vap->iv_des_mode != IEEE80211_MODE_AUTO) {
622 /*
623 * If a desired mode was specified, scan only
624 * channels that satisfy that constraint.
625 */
626 if (vap->iv_des_mode != mode) {
627 /*
628 * The scan table marks 2.4Ghz channels as b
629 * so if the desired mode is 11g, then use
630 * the 11b channel list but upgrade the mode.
631 */
632 if (vap->iv_des_mode == IEEE80211_MODE_11G) {
633 if (mode == IEEE80211_MODE_11G) /* Skip the G check */
634 continue;
635 else if (mode == IEEE80211_MODE_11B)
636 mode = IEEE80211_MODE_11G; /* upgrade */
637 }
638 }
639 } else {
640 /*
641 * This lets add_channels upgrade an 11b channel
642 * to 11g if available.
643 */
644 if (mode == IEEE80211_MODE_11B)
645 mode = IEEE80211_MODE_AUTO;
646 }
647 #ifdef IEEE80211_F_XR
648 /* XR does not operate on turbo channels */
649 if ((vap->iv_flags & IEEE80211_F_XR) &&
650 (mode == IEEE80211_MODE_TURBO_A ||
651 mode == IEEE80211_MODE_TURBO_G ||
652 mode == IEEE80211_MODE_STURBO_A))
653 continue;
654 #endif
655 /*
656 * Add the list of the channels; any that are not
657 * in the master channel list will be discarded.
658 */
659 add_channels(vap, ss, mode, scan->list, scan->count);
660 }
661
662 /*
663 * Add the channels from the ic that are not present
664 * in the table.
665 */
666 sweepchannels(ss, vap, table);
667 }
668
669 static const uint16_t rcl1[] = /* 8 FCC channel: 52, 56, 60, 64, 36, 40, 44, 48 */
670 { 5260, 5280, 5300, 5320, 5180, 5200, 5220, 5240 };
671 static const uint16_t rcl2[] = /* 4 MKK channels: 34, 38, 42, 46 */
672 { 5170, 5190, 5210, 5230 };
673 static const uint16_t rcl3[] = /* 2.4Ghz ch: 1,6,11,7,13 */
674 { 2412, 2437, 2462, 2442, 2472 };
675 static const uint16_t rcl4[] = /* 5 FCC channel: 149, 153, 161, 165 */
676 { 5745, 5765, 5785, 5805, 5825 };
677 static const uint16_t rcl7[] = /* 11 ETSI channel: 100,104,108,112,116,120,124,128,132,136,140 */
678 { 5500, 5520, 5540, 5560, 5580, 5600, 5620, 5640, 5660, 5680, 5700 };
679 static const uint16_t rcl8[] = /* 2.4Ghz ch: 2,3,4,5,8,9,10,12 */
680 { 2417, 2422, 2427, 2432, 2447, 2452, 2457, 2467 };
681 static const uint16_t rcl9[] = /* 2.4Ghz ch: 14 */
682 { 2484 };
683 static const uint16_t rcl10[] = /* Added Korean channels 2312-2372 */
684 { 2312, 2317, 2322, 2327, 2332, 2337, 2342, 2347, 2352, 2357, 2362, 2367, 2372 };
685 static const uint16_t rcl11[] = /* Added Japan channels in 4.9/5.0 spectrum */
686 { 5040, 5060, 5080, 4920, 4940, 4960, 4980 };
687 #ifdef ATH_TURBO_SCAN
688 static const uint16_t rcl5[] = /* 3 static turbo channels */
689 { 5210, 5250, 5290 };
690 static const uint16_t rcl6[] = /* 2 static turbo channels */
691 { 5760, 5800 };
692 static const uint16_t rcl6x[] = /* 4 FCC3 turbo channels */
693 { 5540, 5580, 5620, 5660 };
694 static const uint16_t rcl12[] = /* 2.4Ghz Turbo channel 6 */
695 { 2437 };
696 static const uint16_t rcl13[] = /* dynamic Turbo channels */
697 { 5200, 5240, 5280, 5765, 5805 };
698 #endif /* ATH_TURBO_SCAN */
699
700 #define X(a) .count = sizeof(a)/sizeof(a[0]), .list = a
701
702 static const struct scanlist staScanTable[] = {
703 { IEEE80211_MODE_11B, X(rcl3) },
704 { IEEE80211_MODE_11A, X(rcl1) },
705 { IEEE80211_MODE_11A, X(rcl2) },
706 { IEEE80211_MODE_11B, X(rcl8) },
707 { IEEE80211_MODE_11B, X(rcl9) },
708 { IEEE80211_MODE_11A, X(rcl4) },
709 #ifdef ATH_TURBO_SCAN
710 { IEEE80211_MODE_STURBO_A, X(rcl5) },
711 { IEEE80211_MODE_STURBO_A, X(rcl6) },
712 { IEEE80211_MODE_TURBO_A, X(rcl6x) },
713 { IEEE80211_MODE_TURBO_A, X(rcl13) },
714 #endif /* ATH_TURBO_SCAN */
715 { IEEE80211_MODE_11A, X(rcl7) },
716 { IEEE80211_MODE_11B, X(rcl10) },
717 { IEEE80211_MODE_11A, X(rcl11) },
718 #ifdef ATH_TURBO_SCAN
719 { IEEE80211_MODE_TURBO_G, X(rcl12) },
720 #endif /* ATH_TURBO_SCAN */
721 { .list = NULL }
722 };
723
724 /*
725 * Start a station-mode scan by populating the channel list.
726 */
727 static int
728 sta_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
729 {
730 struct sta_table *st = ss->ss_priv;
731
732 makescanlist(ss, vap, staScanTable);
733
734 if (ss->ss_mindwell == 0)
735 ss->ss_mindwell = msecs_to_ticks(20); /* 20ms */
736 if (ss->ss_maxdwell == 0)
737 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
738
739 st->st_scangen++;
740 st->st_newscan = 1;
741
742 return 0;
743 }
744
745 /*
746 * Restart a scan, typically a bg scan but can
747 * also be a fg scan that came up empty.
748 */
749 static int
750 sta_restart(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
751 {
752 struct sta_table *st = ss->ss_priv;
753
754 st->st_newscan = 1;
755 return 0;
756 }
757
758 /*
759 * Cancel an ongoing scan.
760 */
761 static int
762 sta_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
763 {
764 return 0;
765 }
766
767 /*
768 * Demote any supplied 11g channel to 11b. There should
769 * always be an 11b channel but we check anyway...
770 */
771 static struct ieee80211_channel *
772 demote11b(struct ieee80211vap *vap, struct ieee80211_channel *chan)
773 {
774 struct ieee80211_channel *c;
775
776 if (IEEE80211_IS_CHAN_ANYG(chan) &&
777 vap->iv_des_mode == IEEE80211_MODE_AUTO) {
778 c = ieee80211_find_channel(vap->iv_ic, chan->ic_freq,
779 (chan->ic_flags &~ (IEEE80211_CHAN_PUREG | IEEE80211_CHAN_G)) |
780 IEEE80211_CHAN_B);
781 if (c != NULL)
782 chan = c;
783 }
784 return chan;
785 }
786
787 static int
788 maxrate(const struct ieee80211_scan_entry *se)
789 {
790 const struct ieee80211_ie_htcap *htcap =
791 (const struct ieee80211_ie_htcap *) se->se_ies.htcap_ie;
792 int rmax, r, i, txstream;
793 uint16_t caps;
794 uint8_t txparams;
795
796 rmax = 0;
797 if (htcap != NULL) {
798 /*
799 * HT station; inspect supported MCS and then adjust
800 * rate by channel width.
801 */
802 txparams = htcap->hc_mcsset[12];
803 if (txparams & 0x3) {
804 /*
805 * TX MCS parameters defined and not equal to RX,
806 * extract the number of spartial streams and
807 * map it to the highest MCS rate.
808 */
809 txstream = ((txparams & 0xc) >> 2) + 1;
810 i = txstream * 8 - 1;
811 } else
812 for (i = 31; i >= 0 && isclr(htcap->hc_mcsset, i); i--);
813 if (i >= 0) {
814 caps = le16dec(&htcap->hc_cap);
815 if ((caps & IEEE80211_HTCAP_CHWIDTH40) &&
816 (caps & IEEE80211_HTCAP_SHORTGI40))
817 rmax = ieee80211_htrates[i].ht40_rate_400ns;
818 else if (caps & IEEE80211_HTCAP_CHWIDTH40)
819 rmax = ieee80211_htrates[i].ht40_rate_800ns;
820 else if (caps & IEEE80211_HTCAP_SHORTGI20)
821 rmax = ieee80211_htrates[i].ht20_rate_400ns;
822 else
823 rmax = ieee80211_htrates[i].ht20_rate_800ns;
824 }
825 }
826 for (i = 0; i < se->se_rates[1]; i++) {
827 r = se->se_rates[2+i] & IEEE80211_RATE_VAL;
828 if (r > rmax)
829 rmax = r;
830 }
831 for (i = 0; i < se->se_xrates[1]; i++) {
832 r = se->se_xrates[2+i] & IEEE80211_RATE_VAL;
833 if (r > rmax)
834 rmax = r;
835 }
836 return rmax;
837 }
838
839 /*
840 * Compare the capabilities of two entries and decide which is
841 * more desirable (return >0 if a is considered better). Note
842 * that we assume compatibility/usability has already been checked
843 * so we don't need to (e.g. validate whether privacy is supported).
844 * Used to select the best scan candidate for association in a BSS.
845 *
846 * TODO: should we take 11n, 11ac into account when selecting the
847 * best? Right now it just compares frequency band and RSSI.
848 */
849 static int
850 sta_compare(const struct sta_entry *a, const struct sta_entry *b)
851 {
852 #define PREFER(_a,_b,_what) do { \
853 if (((_a) ^ (_b)) & (_what)) \
854 return ((_a) & (_what)) ? 1 : -1; \
855 } while (0)
856 int maxa, maxb;
857 int8_t rssia, rssib;
858 int weight;
859
860 /* privacy support */
861 PREFER(a->base.se_capinfo, b->base.se_capinfo,
862 IEEE80211_CAPINFO_PRIVACY);
863
864 /* compare count of previous failures */
865 weight = b->se_fails - a->se_fails;
866 if (abs(weight) > 1)
867 return weight;
868
869 /*
870 * Compare rssi. If the two are considered equivalent
871 * then fallback to other criteria. We threshold the
872 * comparisons to avoid selecting an ap purely by rssi
873 * when both values may be good but one ap is otherwise
874 * more desirable (e.g. an 11b-only ap with stronger
875 * signal than an 11g ap).
876 */
877 rssia = MIN(a->base.se_rssi, STA_RSSI_MAX);
878 rssib = MIN(b->base.se_rssi, STA_RSSI_MAX);
879 if (abs(rssib - rssia) < 5) {
880 /* best/max rate preferred if signal level close enough XXX */
881 maxa = maxrate(&a->base);
882 maxb = maxrate(&b->base);
883 if (maxa != maxb)
884 return maxa - maxb;
885 /* XXX use freq for channel preference */
886 /* for now just prefer 5Ghz band to all other bands */
887 PREFER(IEEE80211_IS_CHAN_5GHZ(a->base.se_chan),
888 IEEE80211_IS_CHAN_5GHZ(b->base.se_chan), 1);
889 }
890 /* all things being equal, use signal level */
891 return a->base.se_rssi - b->base.se_rssi;
892 #undef PREFER
893 }
894
895 /*
896 * Check rate set suitability and return the best supported rate.
897 * XXX inspect MCS for HT
898 */
899 static int
900 check_rate(struct ieee80211vap *vap, const struct ieee80211_channel *chan,
901 const struct ieee80211_scan_entry *se)
902 {
903 const struct ieee80211_rateset *srs;
904 int i, j, nrs, r, okrate, badrate, fixedrate, ucastrate;
905 const uint8_t *rs;
906
907 okrate = badrate = 0;
908
909 srs = ieee80211_get_suprates(vap->iv_ic, chan);
910 nrs = se->se_rates[1];
911 rs = se->se_rates+2;
912 /* XXX MCS */
913 ucastrate = vap->iv_txparms[ieee80211_chan2mode(chan)].ucastrate;
914 fixedrate = IEEE80211_FIXED_RATE_NONE;
915 again:
916 for (i = 0; i < nrs; i++) {
917 r = IEEE80211_RV(rs[i]);
918 badrate = r;
919 /*
920 * Check any fixed rate is included.
921 */
922 if (r == ucastrate)
923 fixedrate = r;
924 /*
925 * Check against our supported rates.
926 */
927 for (j = 0; j < srs->rs_nrates; j++)
928 if (r == IEEE80211_RV(srs->rs_rates[j])) {
929 if (r > okrate) /* NB: track max */
930 okrate = r;
931 break;
932 }
933
934 if (j == srs->rs_nrates && (rs[i] & IEEE80211_RATE_BASIC)) {
935 /*
936 * Don't try joining a BSS, if we don't support
937 * one of its basic rates.
938 */
939 okrate = 0;
940 goto back;
941 }
942 }
943 if (rs == se->se_rates+2) {
944 /* scan xrates too; sort of an algol68-style for loop */
945 nrs = se->se_xrates[1];
946 rs = se->se_xrates+2;
947 goto again;
948 }
949
950 back:
951 if (okrate == 0 || ucastrate != fixedrate)
952 return badrate | IEEE80211_RATE_BASIC;
953 else
954 return IEEE80211_RV(okrate);
955 }
956
957 static __inline int
958 match_id(const uint8_t *ie, const uint8_t *val, int len)
959 {
960 return (ie[1] == len && memcmp(ie+2, val, len) == 0);
961 }
962
963 static int
964 match_ssid(const uint8_t *ie,
965 int nssid, const struct ieee80211_scan_ssid ssids[])
966 {
967 int i;
968
969 for (i = 0; i < nssid; i++) {
970 if (match_id(ie, ssids[i].ssid, ssids[i].len))
971 return 1;
972 }
973 return 0;
974 }
975
976 #ifdef IEEE80211_SUPPORT_TDMA
977 static int
978 tdma_isfull(const struct ieee80211_tdma_param *tdma)
979 {
980 int slot, slotcnt;
981
982 slotcnt = tdma->tdma_slotcnt;
983 for (slot = slotcnt-1; slot >= 0; slot--)
984 if (isclr(tdma->tdma_inuse, slot))
985 return 0;
986 return 1;
987 }
988 #endif /* IEEE80211_SUPPORT_TDMA */
989
990 /*
991 * Test a scan candidate for suitability/compatibility.
992 */
993 static int
994 match_bss(struct ieee80211vap *vap,
995 const struct ieee80211_scan_state *ss, struct sta_entry *se0,
996 int debug)
997 {
998 struct ieee80211com *ic = vap->iv_ic;
999 struct ieee80211_scan_entry *se = &se0->base;
1000 uint8_t rate;
1001 int fail;
1002
1003 fail = 0;
1004 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, se->se_chan)))
1005 fail |= MATCH_CHANNEL;
1006 /*
1007 * NB: normally the desired mode is used to construct
1008 * the channel list, but it's possible for the scan
1009 * cache to include entries for stations outside this
1010 * list so we check the desired mode here to weed them
1011 * out.
1012 */
1013 if (vap->iv_des_mode != IEEE80211_MODE_AUTO &&
1014 (se->se_chan->ic_flags & IEEE80211_CHAN_ALLTURBO) !=
1015 chanflags[vap->iv_des_mode])
1016 fail |= MATCH_CHANNEL;
1017 if (vap->iv_opmode == IEEE80211_M_IBSS) {
1018 if ((se->se_capinfo & IEEE80211_CAPINFO_IBSS) == 0)
1019 fail |= MATCH_CAPINFO;
1020 #ifdef IEEE80211_SUPPORT_TDMA
1021 } else if (vap->iv_opmode == IEEE80211_M_AHDEMO) {
1022 /*
1023 * Adhoc demo network setup shouldn't really be scanning
1024 * but just in case skip stations operating in IBSS or
1025 * BSS mode.
1026 */
1027 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS))
1028 fail |= MATCH_CAPINFO;
1029 /*
1030 * TDMA operation cannot coexist with a normal 802.11 network;
1031 * skip if IBSS or ESS capabilities are marked and require
1032 * the beacon have a TDMA ie present.
1033 */
1034 if (vap->iv_caps & IEEE80211_C_TDMA) {
1035 const struct ieee80211_tdma_param *tdma =
1036 (const struct ieee80211_tdma_param *)se->se_ies.tdma_ie;
1037 const struct ieee80211_tdma_state *ts = vap->iv_tdma;
1038
1039 if (tdma == NULL)
1040 fail |= MATCH_TDMA_NOIE;
1041 else if (tdma->tdma_version != ts->tdma_version)
1042 fail |= MATCH_TDMA_VERSION;
1043 else if (tdma->tdma_slot != 0)
1044 fail |= MATCH_TDMA_NOTMASTER;
1045 else if (tdma_isfull(tdma))
1046 fail |= MATCH_TDMA_NOSLOT;
1047 #if 0
1048 else if (ieee80211_local_address(se->se_macaddr))
1049 fail |= MATCH_TDMA_LOCAL;
1050 #endif
1051 }
1052 #endif /* IEEE80211_SUPPORT_TDMA */
1053 #ifdef IEEE80211_SUPPORT_MESH
1054 } else if (vap->iv_opmode == IEEE80211_M_MBSS) {
1055 const struct ieee80211_mesh_state *ms = vap->iv_mesh;
1056 /*
1057 * Mesh nodes have IBSS & ESS bits in capinfo turned off
1058 * and two special ie's that must be present.
1059 */
1060 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS))
1061 fail |= MATCH_CAPINFO;
1062 else if (se->se_meshid[0] != IEEE80211_ELEMID_MESHID)
1063 fail |= MATCH_MESH_NOID;
1064 else if (ms->ms_idlen != 0 &&
1065 match_id(se->se_meshid, ms->ms_id, ms->ms_idlen))
1066 fail |= MATCH_MESHID;
1067 #endif
1068 } else {
1069 if ((se->se_capinfo & IEEE80211_CAPINFO_ESS) == 0)
1070 fail |= MATCH_CAPINFO;
1071 /*
1072 * If 11d is enabled and we're attempting to join a bss
1073 * that advertises it's country code then compare our
1074 * current settings to what we fetched from the country ie.
1075 * If our country code is unspecified or different then do
1076 * not attempt to join the bss. We should have already
1077 * dispatched an event to user space that identifies the
1078 * new country code so our regdomain config should match.
1079 */
1080 if ((IEEE80211_IS_CHAN_11D(se->se_chan) ||
1081 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) &&
1082 se->se_cc[0] != 0 &&
1083 (ic->ic_regdomain.country == CTRY_DEFAULT ||
1084 !isocmp(se->se_cc, ic->ic_regdomain.isocc)))
1085 fail |= MATCH_CC;
1086 }
1087 if (vap->iv_flags & IEEE80211_F_PRIVACY) {
1088 if ((se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0)
1089 fail |= MATCH_PRIVACY;
1090 } else {
1091 /* XXX does this mean privacy is supported or required? */
1092 if (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY)
1093 fail |= MATCH_PRIVACY;
1094 }
1095 se0->se_flags &= ~STA_DEMOTE11B;
1096 rate = check_rate(vap, se->se_chan, se);
1097 if (rate & IEEE80211_RATE_BASIC) {
1098 fail |= MATCH_RATE;
1099 /*
1100 * An 11b-only ap will give a rate mismatch if there is an
1101 * OFDM fixed tx rate for 11g. Try downgrading the channel
1102 * in the scan list to 11b and retry the rate check.
1103 */
1104 if (IEEE80211_IS_CHAN_ANYG(se->se_chan)) {
1105 rate = check_rate(vap, demote11b(vap, se->se_chan), se);
1106 if ((rate & IEEE80211_RATE_BASIC) == 0) {
1107 fail &= ~MATCH_RATE;
1108 se0->se_flags |= STA_DEMOTE11B;
1109 }
1110 }
1111 } else if (rate < 2*24) {
1112 /*
1113 * This is an 11b-only ap. Check the desired mode in
1114 * case that needs to be honored (mode 11g filters out
1115 * 11b-only ap's). Otherwise force any 11g channel used
1116 * in scanning to be demoted.
1117 *
1118 * NB: we cheat a bit here by looking at the max rate;
1119 * we could/should check the rates.
1120 */
1121 if (!(vap->iv_des_mode == IEEE80211_MODE_AUTO ||
1122 vap->iv_des_mode == IEEE80211_MODE_11B))
1123 fail |= MATCH_RATE;
1124 else
1125 se0->se_flags |= STA_DEMOTE11B;
1126 }
1127 if (ss->ss_nssid != 0 &&
1128 !match_ssid(se->se_ssid, ss->ss_nssid, ss->ss_ssid))
1129 fail |= MATCH_SSID;
1130 if ((vap->iv_flags & IEEE80211_F_DESBSSID) &&
1131 !IEEE80211_ADDR_EQ(vap->iv_des_bssid, se->se_bssid))
1132 fail |= MATCH_BSSID;
1133 if (se0->se_fails >= STA_FAILS_MAX)
1134 fail |= MATCH_FAILS;
1135 if (se0->se_notseen >= STA_PURGE_SCANS)
1136 fail |= MATCH_NOTSEEN;
1137 if (se->se_rssi < STA_RSSI_MIN)
1138 fail |= MATCH_RSSI;
1139 #ifdef IEEE80211_DEBUG
1140 if (ieee80211_msg(vap, debug)) {
1141 printf(" %c %s",
1142 fail & MATCH_FAILS ? '=' :
1143 fail & MATCH_NOTSEEN ? '^' :
1144 fail & MATCH_CC ? '$' :
1145 #ifdef IEEE80211_SUPPORT_TDMA
1146 fail & MATCH_TDMA_NOIE ? '&' :
1147 fail & MATCH_TDMA_VERSION ? 'v' :
1148 fail & MATCH_TDMA_NOTMASTER ? 's' :
1149 fail & MATCH_TDMA_NOSLOT ? 'f' :
1150 fail & MATCH_TDMA_LOCAL ? 'l' :
1151 #endif
1152 fail & MATCH_MESH_NOID ? 'm' :
1153 fail ? '-' : '+', ether_sprintf(se->se_macaddr));
1154 printf(" %s%c", ether_sprintf(se->se_bssid),
1155 fail & MATCH_BSSID ? '!' : ' ');
1156 printf(" %3d%c", ieee80211_chan2ieee(ic, se->se_chan),
1157 fail & MATCH_CHANNEL ? '!' : ' ');
1158 printf(" %+4d%c", se->se_rssi, fail & MATCH_RSSI ? '!' : ' ');
1159 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2,
1160 fail & MATCH_RATE ? '!' : ' ');
1161 printf(" %4s%c",
1162 (se->se_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" :
1163 (se->se_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : "",
1164 fail & MATCH_CAPINFO ? '!' : ' ');
1165 printf(" %3s%c ",
1166 (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) ?
1167 "wep" : "no",
1168 fail & MATCH_PRIVACY ? '!' : ' ');
1169 ieee80211_print_essid(se->se_ssid+2, se->se_ssid[1]);
1170 printf("%s\n", fail & (MATCH_SSID | MATCH_MESHID) ? "!" : "");
1171 }
1172 #endif
1173 return fail;
1174 }
1175
1176 static void
1177 sta_update_notseen(struct sta_table *st)
1178 {
1179 struct sta_entry *se;
1180
1181 IEEE80211_SCAN_TABLE_LOCK(st);
1182 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1183 /*
1184 * If seen the reset and don't bump the count;
1185 * otherwise bump the ``not seen'' count. Note
1186 * that this insures that stations for which we
1187 * see frames while not scanning but not during
1188 * this scan will not be penalized.
1189 */
1190 if (se->se_seen)
1191 se->se_seen = 0;
1192 else
1193 se->se_notseen++;
1194 }
1195 IEEE80211_SCAN_TABLE_UNLOCK(st);
1196 }
1197
1198 static void
1199 sta_dec_fails(struct sta_table *st)
1200 {
1201 struct sta_entry *se;
1202
1203 IEEE80211_SCAN_TABLE_LOCK(st);
1204 TAILQ_FOREACH(se, &st->st_entry, se_list)
1205 if (se->se_fails)
1206 se->se_fails--;
1207 IEEE80211_SCAN_TABLE_UNLOCK(st);
1208 }
1209
1210 static struct sta_entry *
1211 select_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, int debug)
1212 {
1213 struct sta_table *st = ss->ss_priv;
1214 struct sta_entry *se, *selbs = NULL;
1215
1216 IEEE80211_DPRINTF(vap, debug, " %s\n",
1217 "macaddr bssid chan rssi rate flag wep essid");
1218 IEEE80211_SCAN_TABLE_LOCK(st);
1219 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1220 ieee80211_ies_expand(&se->base.se_ies);
1221 if (match_bss(vap, ss, se, debug) == 0) {
1222 if (selbs == NULL)
1223 selbs = se;
1224 else if (sta_compare(se, selbs) > 0)
1225 selbs = se;
1226 }
1227 }
1228 IEEE80211_SCAN_TABLE_UNLOCK(st);
1229
1230 return selbs;
1231 }
1232
1233 /*
1234 * Pick an ap or ibss network to join or find a channel
1235 * to use to start an ibss network.
1236 */
1237 static int
1238 sta_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1239 {
1240 struct sta_table *st = ss->ss_priv;
1241 struct sta_entry *selbs;
1242 struct ieee80211_channel *chan;
1243
1244 KASSERT(vap->iv_opmode == IEEE80211_M_STA,
1245 ("wrong mode %u", vap->iv_opmode));
1246
1247 if (st->st_newscan) {
1248 sta_update_notseen(st);
1249 st->st_newscan = 0;
1250 }
1251 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1252 /*
1253 * Manual/background scan, don't select+join the
1254 * bss, just return. The scanning framework will
1255 * handle notification that this has completed.
1256 */
1257 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1258 return 1;
1259 }
1260 /*
1261 * Automatic sequencing; look for a candidate and
1262 * if found join the network.
1263 */
1264 /* NB: unlocked read should be ok */
1265 if (TAILQ_FIRST(&st->st_entry) == NULL) {
1266 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1267 "%s: no scan candidate\n", __func__);
1268 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1269 return 0;
1270 notfound:
1271 /*
1272 * If nothing suitable was found decrement
1273 * the failure counts so entries will be
1274 * reconsidered the next time around. We
1275 * really want to do this only for sta's
1276 * where we've previously had some success.
1277 */
1278 sta_dec_fails(st);
1279 st->st_newscan = 1;
1280 return 0; /* restart scan */
1281 }
1282 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1283 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1284 return (selbs != NULL);
1285 if (selbs == NULL)
1286 goto notfound;
1287 chan = selbs->base.se_chan;
1288 if (selbs->se_flags & STA_DEMOTE11B)
1289 chan = demote11b(vap, chan);
1290 if (!ieee80211_sta_join(vap, chan, &selbs->base))
1291 goto notfound;
1292 return 1; /* terminate scan */
1293 }
1294
1295 /*
1296 * Lookup an entry in the scan cache. We assume we're
1297 * called from the bottom half or such that we don't need
1298 * to block the bottom half so that it's safe to return
1299 * a reference to an entry w/o holding the lock on the table.
1300 */
1301 static struct sta_entry *
1302 sta_lookup(struct sta_table *st, const uint8_t macaddr[IEEE80211_ADDR_LEN])
1303 {
1304 struct sta_entry *se;
1305 int hash = STA_HASH(macaddr);
1306
1307 IEEE80211_SCAN_TABLE_LOCK(st);
1308 LIST_FOREACH(se, &st->st_hash[hash], se_hash)
1309 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr))
1310 break;
1311 IEEE80211_SCAN_TABLE_UNLOCK(st);
1312
1313 return se; /* NB: unlocked */
1314 }
1315
1316 static void
1317 sta_roam_check(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1318 {
1319 struct ieee80211com *ic = vap->iv_ic;
1320 struct ieee80211_node *ni = vap->iv_bss;
1321 struct sta_table *st = ss->ss_priv;
1322 enum ieee80211_phymode mode;
1323 struct sta_entry *se, *selbs;
1324 uint8_t roamRate, curRate, ucastRate;
1325 int8_t roamRssi, curRssi;
1326
1327 se = sta_lookup(st, ni->ni_macaddr);
1328 if (se == NULL) {
1329 /* XXX something is wrong */
1330 return;
1331 }
1332
1333 mode = ieee80211_chan2mode(ic->ic_bsschan);
1334 roamRate = vap->iv_roamparms[mode].rate;
1335 roamRssi = vap->iv_roamparms[mode].rssi;
1336 ucastRate = vap->iv_txparms[mode].ucastrate;
1337 /* NB: the most up to date rssi is in the node, not the scan cache */
1338 curRssi = ic->ic_node_getrssi(ni);
1339 if (ucastRate == IEEE80211_FIXED_RATE_NONE) {
1340 curRate = ni->ni_txrate;
1341 roamRate &= IEEE80211_RATE_VAL;
1342 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM,
1343 "%s: currssi %d currate %u roamrssi %d roamrate %u\n",
1344 __func__, curRssi, curRate, roamRssi, roamRate);
1345 } else {
1346 curRate = roamRate; /* NB: insure compare below fails */
1347 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM,
1348 "%s: currssi %d roamrssi %d\n", __func__, curRssi, roamRssi);
1349 }
1350 /*
1351 * Check if a new ap should be used and switch.
1352 * XXX deauth current ap
1353 */
1354 if (curRate < roamRate || curRssi < roamRssi) {
1355 if (ieee80211_time_after(ticks, ic->ic_lastscan + vap->iv_scanvalid)) {
1356 /*
1357 * Scan cache contents are too old; force a scan now
1358 * if possible so we have current state to make a
1359 * decision with. We don't kick off a bg scan if
1360 * we're using dynamic turbo and boosted or if the
1361 * channel is busy.
1362 * XXX force immediate switch on scan complete
1363 */
1364 if (!IEEE80211_IS_CHAN_DTURBO(ic->ic_curchan) &&
1365 ((vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) ||
1366 ieee80211_time_after(ticks, ic->ic_lastdata + vap->iv_bgscanidle)))
1367 ieee80211_bg_scan(vap, 0);
1368 return;
1369 }
1370 se->base.se_rssi = curRssi;
1371 selbs = select_bss(ss, vap, IEEE80211_MSG_ROAM);
1372 if (selbs != NULL && selbs != se) {
1373 struct ieee80211_channel *chan;
1374
1375 IEEE80211_DPRINTF(vap,
1376 IEEE80211_MSG_ROAM | IEEE80211_MSG_DEBUG,
1377 "%s: ROAM: curRate %u, roamRate %u, "
1378 "curRssi %d, roamRssi %d\n", __func__,
1379 curRate, roamRate, curRssi, roamRssi);
1380
1381 chan = selbs->base.se_chan;
1382 if (selbs->se_flags & STA_DEMOTE11B)
1383 chan = demote11b(vap, chan);
1384 (void) ieee80211_sta_join(vap, chan, &selbs->base);
1385 }
1386 }
1387 }
1388
1389 /*
1390 * Age entries in the scan cache.
1391 * XXX also do roaming since it's convenient
1392 */
1393 static void
1394 sta_age(struct ieee80211_scan_state *ss)
1395 {
1396 struct ieee80211vap *vap = ss->ss_vap;
1397
1398 adhoc_age(ss);
1399 /*
1400 * If rate control is enabled check periodically to see if
1401 * we should roam from our current connection to one that
1402 * might be better. This only applies when we're operating
1403 * in sta mode and automatic roaming is set.
1404 * XXX defer if busy
1405 * XXX repeater station
1406 * XXX do when !bgscan?
1407 */
1408 KASSERT(vap->iv_opmode == IEEE80211_M_STA,
1409 ("wrong mode %u", vap->iv_opmode));
1410 if (vap->iv_roaming == IEEE80211_ROAMING_AUTO &&
1411 (vap->iv_flags & IEEE80211_F_BGSCAN) &&
1412 vap->iv_state >= IEEE80211_S_RUN)
1413 /* XXX vap is implicit */
1414 sta_roam_check(ss, vap);
1415 }
1416
1417 /*
1418 * Iterate over the entries in the scan cache, invoking
1419 * the callback function on each one.
1420 */
1421 static void
1422 sta_iterate(struct ieee80211_scan_state *ss,
1423 ieee80211_scan_iter_func *f, void *arg)
1424 {
1425 struct sta_table *st = ss->ss_priv;
1426 struct sta_entry *se;
1427 u_int gen;
1428
1429 IEEE80211_SCAN_ITER_LOCK(st);
1430 gen = st->st_scaniter++;
1431 restart:
1432 IEEE80211_SCAN_TABLE_LOCK(st);
1433 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1434 if (se->se_scangen != gen) {
1435 se->se_scangen = gen;
1436 /* update public state */
1437 se->base.se_age = ticks - se->se_lastupdate;
1438 IEEE80211_SCAN_TABLE_UNLOCK(st);
1439 (*f)(arg, &se->base);
1440 goto restart;
1441 }
1442 }
1443 IEEE80211_SCAN_TABLE_UNLOCK(st);
1444
1445 IEEE80211_SCAN_ITER_UNLOCK(st);
1446 }
1447
1448 static void
1449 sta_assoc_fail(struct ieee80211_scan_state *ss,
1450 const uint8_t macaddr[IEEE80211_ADDR_LEN], int reason)
1451 {
1452 struct sta_table *st = ss->ss_priv;
1453 struct sta_entry *se;
1454
1455 se = sta_lookup(st, macaddr);
1456 if (se != NULL) {
1457 se->se_fails++;
1458 se->se_lastfail = ticks;
1459 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN,
1460 macaddr, "%s: reason %u fails %u",
1461 __func__, reason, se->se_fails);
1462 }
1463 }
1464
1465 static void
1466 sta_assoc_success(struct ieee80211_scan_state *ss,
1467 const uint8_t macaddr[IEEE80211_ADDR_LEN])
1468 {
1469 struct sta_table *st = ss->ss_priv;
1470 struct sta_entry *se;
1471
1472 se = sta_lookup(st, macaddr);
1473 if (se != NULL) {
1474 #if 0
1475 se->se_fails = 0;
1476 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN,
1477 macaddr, "%s: fails %u",
1478 __func__, se->se_fails);
1479 #endif
1480 se->se_lastassoc = ticks;
1481 }
1482 }
1483
1484 static const struct ieee80211_scanner sta_default = {
1485 .scan_name = "default",
1486 .scan_attach = sta_attach,
1487 .scan_detach = sta_detach,
1488 .scan_start = sta_start,
1489 .scan_restart = sta_restart,
1490 .scan_cancel = sta_cancel,
1491 .scan_end = sta_pick_bss,
1492 .scan_flush = sta_flush,
1493 .scan_add = sta_add,
1494 .scan_age = sta_age,
1495 .scan_iterate = sta_iterate,
1496 .scan_assoc_fail = sta_assoc_fail,
1497 .scan_assoc_success = sta_assoc_success,
1498 };
1499 IEEE80211_SCANNER_ALG(sta, IEEE80211_M_STA, sta_default);
1500
1501 /*
1502 * Adhoc mode-specific support.
1503 */
1504
1505 static const uint16_t adhocWorld[] = /* 36, 40, 44, 48 */
1506 { 5180, 5200, 5220, 5240 };
1507 static const uint16_t adhocFcc3[] = /* 36, 40, 44, 48 145, 149, 153, 157, 161, 165 */
1508 { 5180, 5200, 5220, 5240, 5725, 5745, 5765, 5785, 5805, 5825 };
1509 static const uint16_t adhocMkk[] = /* 34, 38, 42, 46 */
1510 { 5170, 5190, 5210, 5230 };
1511 static const uint16_t adhoc11b[] = /* 10, 11 */
1512 { 2457, 2462 };
1513
1514 static const struct scanlist adhocScanTable[] = {
1515 { IEEE80211_MODE_11B, X(adhoc11b) },
1516 { IEEE80211_MODE_11A, X(adhocWorld) },
1517 { IEEE80211_MODE_11A, X(adhocFcc3) },
1518 { IEEE80211_MODE_11B, X(adhocMkk) },
1519 { .list = NULL }
1520 };
1521 #undef X
1522
1523 /*
1524 * Start an adhoc-mode scan by populating the channel list.
1525 */
1526 static int
1527 adhoc_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1528 {
1529 struct sta_table *st = ss->ss_priv;
1530
1531 makescanlist(ss, vap, adhocScanTable);
1532
1533 if (ss->ss_mindwell == 0)
1534 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */
1535 if (ss->ss_maxdwell == 0)
1536 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
1537
1538 st->st_scangen++;
1539 st->st_newscan = 1;
1540
1541 return 0;
1542 }
1543
1544 /*
1545 * Select a channel to start an adhoc network on.
1546 * The channel list was populated with appropriate
1547 * channels so select one that looks least occupied.
1548 */
1549 static struct ieee80211_channel *
1550 adhoc_pick_channel(struct ieee80211_scan_state *ss, int flags)
1551 {
1552 struct sta_table *st = ss->ss_priv;
1553 struct sta_entry *se;
1554 struct ieee80211_channel *c, *bestchan;
1555 int i, bestrssi, maxrssi;
1556
1557 bestchan = NULL;
1558 bestrssi = -1;
1559
1560 IEEE80211_SCAN_TABLE_LOCK(st);
1561 for (i = 0; i < ss->ss_last; i++) {
1562 c = ss->ss_chans[i];
1563 /* never consider a channel with radar */
1564 if (IEEE80211_IS_CHAN_RADAR(c))
1565 continue;
1566 /* skip channels disallowed by regulatory settings */
1567 if (IEEE80211_IS_CHAN_NOADHOC(c))
1568 continue;
1569 /* check channel attributes for band compatibility */
1570 if (flags != 0 && (c->ic_flags & flags) != flags)
1571 continue;
1572 maxrssi = 0;
1573 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1574 if (se->base.se_chan != c)
1575 continue;
1576 if (se->base.se_rssi > maxrssi)
1577 maxrssi = se->base.se_rssi;
1578 }
1579 if (bestchan == NULL || maxrssi < bestrssi)
1580 bestchan = c;
1581 }
1582 IEEE80211_SCAN_TABLE_UNLOCK(st);
1583
1584 return bestchan;
1585 }
1586
1587 /*
1588 * Pick an ibss network to join or find a channel
1589 * to use to start an ibss network.
1590 */
1591 static int
1592 adhoc_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1593 {
1594 struct sta_table *st = ss->ss_priv;
1595 struct sta_entry *selbs;
1596 struct ieee80211_channel *chan;
1597 struct ieee80211com *ic = vap->iv_ic;
1598
1599 KASSERT(vap->iv_opmode == IEEE80211_M_IBSS ||
1600 vap->iv_opmode == IEEE80211_M_AHDEMO ||
1601 vap->iv_opmode == IEEE80211_M_MBSS,
1602 ("wrong opmode %u", vap->iv_opmode));
1603
1604 if (st->st_newscan) {
1605 sta_update_notseen(st);
1606 st->st_newscan = 0;
1607 }
1608 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1609 /*
1610 * Manual/background scan, don't select+join the
1611 * bss, just return. The scanning framework will
1612 * handle notification that this has completed.
1613 */
1614 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1615 return 1;
1616 }
1617 /*
1618 * Automatic sequencing; look for a candidate and
1619 * if found join the network.
1620 */
1621 /* NB: unlocked read should be ok */
1622 if (TAILQ_FIRST(&st->st_entry) == NULL) {
1623 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1624 "%s: no scan candidate\n", __func__);
1625 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1626 return 0;
1627 notfound:
1628 /* NB: never auto-start a tdma network for slot !0 */
1629 #ifdef IEEE80211_SUPPORT_TDMA
1630 if (vap->iv_des_nssid &&
1631 ((vap->iv_caps & IEEE80211_C_TDMA) == 0 ||
1632 ieee80211_tdma_getslot(vap) == 0)) {
1633 #else
1634 if (vap->iv_des_nssid) {
1635 #endif
1636 /*
1637 * No existing adhoc network to join and we have
1638 * an ssid; start one up. If no channel was
1639 * specified, try to select a channel.
1640 */
1641 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC ||
1642 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
1643 chan = adhoc_pick_channel(ss, 0);
1644 } else
1645 chan = vap->iv_des_chan;
1646 if (chan != NULL) {
1647 /*
1648 * Create a HT capable IBSS; the per-node
1649 * probe request/response will result in
1650 * "correct" rate control capabilities being
1651 * negotiated.
1652 */
1653 chan = ieee80211_ht_adjust_channel(ic,
1654 chan, vap->iv_flags_ht);
1655 chan = ieee80211_vht_adjust_channel(ic,
1656 chan, vap->iv_flags_vht);
1657 ieee80211_create_ibss(vap, chan);
1658 return 1;
1659 }
1660 }
1661 /*
1662 * If nothing suitable was found decrement
1663 * the failure counts so entries will be
1664 * reconsidered the next time around. We
1665 * really want to do this only for sta's
1666 * where we've previously had some success.
1667 */
1668 sta_dec_fails(st);
1669 st->st_newscan = 1;
1670 return 0; /* restart scan */
1671 }
1672 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1673 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1674 return (selbs != NULL);
1675 if (selbs == NULL)
1676 goto notfound;
1677 chan = selbs->base.se_chan;
1678 if (selbs->se_flags & STA_DEMOTE11B)
1679 chan = demote11b(vap, chan);
1680 /*
1681 * If HT is available, make it a possibility here.
1682 * The intent is to enable HT20/HT40 when joining a non-HT
1683 * IBSS node; we can then advertise HT IEs and speak HT
1684 * to any subsequent nodes that support it.
1685 */
1686 chan = ieee80211_ht_adjust_channel(ic,
1687 chan, vap->iv_flags_ht);
1688 chan = ieee80211_vht_adjust_channel(ic,
1689 chan, vap->iv_flags_vht);
1690 if (!ieee80211_sta_join(vap, chan, &selbs->base))
1691 goto notfound;
1692 return 1; /* terminate scan */
1693 }
1694
1695 /*
1696 * Age entries in the scan cache.
1697 */
1698 static void
1699 adhoc_age(struct ieee80211_scan_state *ss)
1700 {
1701 struct sta_table *st = ss->ss_priv;
1702 struct sta_entry *se, *next;
1703
1704 IEEE80211_SCAN_TABLE_LOCK(st);
1705 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) {
1706 if (se->se_notseen > STA_PURGE_SCANS) {
1707 TAILQ_REMOVE(&st->st_entry, se, se_list);
1708 LIST_REMOVE(se, se_hash);
1709 ieee80211_ies_cleanup(&se->base.se_ies);
1710 IEEE80211_FREE(se, M_80211_SCAN);
1711 }
1712 }
1713 IEEE80211_SCAN_TABLE_UNLOCK(st);
1714 }
1715
1716 static const struct ieee80211_scanner adhoc_default = {
1717 .scan_name = "default",
1718 .scan_attach = sta_attach,
1719 .scan_detach = sta_detach,
1720 .scan_start = adhoc_start,
1721 .scan_restart = sta_restart,
1722 .scan_cancel = sta_cancel,
1723 .scan_end = adhoc_pick_bss,
1724 .scan_flush = sta_flush,
1725 .scan_pickchan = adhoc_pick_channel,
1726 .scan_add = sta_add,
1727 .scan_age = adhoc_age,
1728 .scan_iterate = sta_iterate,
1729 .scan_assoc_fail = sta_assoc_fail,
1730 .scan_assoc_success = sta_assoc_success,
1731 };
1732 IEEE80211_SCANNER_ALG(ibss, IEEE80211_M_IBSS, adhoc_default);
1733 IEEE80211_SCANNER_ALG(ahdemo, IEEE80211_M_AHDEMO, adhoc_default);
1734
1735 static int
1736 ap_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1737 {
1738 struct sta_table *st = ss->ss_priv;
1739
1740 makescanlist(ss, vap, staScanTable);
1741
1742 if (ss->ss_mindwell == 0)
1743 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */
1744 if (ss->ss_maxdwell == 0)
1745 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
1746
1747 st->st_scangen++;
1748 st->st_newscan = 1;
1749
1750 return 0;
1751 }
1752
1753 /*
1754 * Cancel an ongoing scan.
1755 */
1756 static int
1757 ap_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1758 {
1759 return 0;
1760 }
1761
1762 /*
1763 * Pick a quiet channel to use for ap operation.
1764 */
1765 static struct ieee80211_channel *
1766 ap_pick_channel(struct ieee80211_scan_state *ss, int flags)
1767 {
1768 struct sta_table *st = ss->ss_priv;
1769 struct ieee80211_channel *bestchan = NULL;
1770 int i;
1771
1772 /* XXX select channel more intelligently, e.g. channel spread, power */
1773 /* NB: use scan list order to preserve channel preference */
1774 for (i = 0; i < ss->ss_last; i++) {
1775 struct ieee80211_channel *chan = ss->ss_chans[i];
1776 /*
1777 * If the channel is unoccupied the max rssi
1778 * should be zero; just take it. Otherwise
1779 * track the channel with the lowest rssi and
1780 * use that when all channels appear occupied.
1781 */
1782 if (IEEE80211_IS_CHAN_RADAR(chan))
1783 continue;
1784 if (IEEE80211_IS_CHAN_NOHOSTAP(chan))
1785 continue;
1786 /* check channel attributes for band compatibility */
1787 if (flags != 0 && (chan->ic_flags & flags) != flags)
1788 continue;
1789 KASSERT(sizeof(chan->ic_ieee) == 1, ("ic_chan size"));
1790 /* XXX channel have interference */
1791 if (st->st_maxrssi[chan->ic_ieee] == 0) {
1792 /* XXX use other considerations */
1793 return chan;
1794 }
1795 if (bestchan == NULL ||
1796 st->st_maxrssi[chan->ic_ieee] < st->st_maxrssi[bestchan->ic_ieee])
1797 bestchan = chan;
1798 }
1799 return bestchan;
1800 }
1801
1802 /*
1803 * Pick a quiet channel to use for ap operation.
1804 */
1805 static int
1806 ap_end(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1807 {
1808 struct ieee80211com *ic = vap->iv_ic;
1809 struct ieee80211_channel *bestchan, *chan;
1810
1811 KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP,
1812 ("wrong opmode %u", vap->iv_opmode));
1813 bestchan = ap_pick_channel(ss, 0);
1814 if (bestchan == NULL) {
1815 /* no suitable channel, should not happen */
1816 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1817 "%s: no suitable channel! (should not happen)\n", __func__);
1818 /* XXX print something? */
1819 return 0; /* restart scan */
1820 }
1821 /*
1822 * If this is a dynamic turbo channel, start with the unboosted one.
1823 */
1824 if (IEEE80211_IS_CHAN_TURBO(bestchan)) {
1825 bestchan = ieee80211_find_channel(ic, bestchan->ic_freq,
1826 bestchan->ic_flags & ~IEEE80211_CHAN_TURBO);
1827 if (bestchan == NULL) {
1828 /* should never happen ?? */
1829 return 0;
1830 }
1831 }
1832 if (ss->ss_flags & (IEEE80211_SCAN_NOPICK | IEEE80211_SCAN_NOJOIN)) {
1833 /*
1834 * Manual/background scan, don't select+join the
1835 * bss, just return. The scanning framework will
1836 * handle notification that this has completed.
1837 */
1838 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1839 return 1;
1840 }
1841 chan = ieee80211_ht_adjust_channel(ic, bestchan, vap->iv_flags_ht);
1842 chan = ieee80211_vht_adjust_channel(ic, chan, vap->iv_flags_vht);
1843 ieee80211_create_ibss(vap, chan);
1844
1845 return 1;
1846 }
1847
1848 static const struct ieee80211_scanner ap_default = {
1849 .scan_name = "default",
1850 .scan_attach = sta_attach,
1851 .scan_detach = sta_detach,
1852 .scan_start = ap_start,
1853 .scan_restart = sta_restart,
1854 .scan_cancel = ap_cancel,
1855 .scan_end = ap_end,
1856 .scan_flush = sta_flush,
1857 .scan_pickchan = ap_pick_channel,
1858 .scan_add = sta_add,
1859 .scan_age = adhoc_age,
1860 .scan_iterate = sta_iterate,
1861 .scan_assoc_success = sta_assoc_success,
1862 .scan_assoc_fail = sta_assoc_fail,
1863 };
1864 IEEE80211_SCANNER_ALG(ap, IEEE80211_M_HOSTAP, ap_default);
1865
1866 #ifdef IEEE80211_SUPPORT_MESH
1867 /*
1868 * Pick an mbss network to join or find a channel
1869 * to use to start an mbss network.
1870 */
1871 static int
1872 mesh_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1873 {
1874 struct sta_table *st = ss->ss_priv;
1875 struct ieee80211_mesh_state *ms = vap->iv_mesh;
1876 struct sta_entry *selbs;
1877 struct ieee80211_channel *chan;
1878
1879 KASSERT(vap->iv_opmode == IEEE80211_M_MBSS,
1880 ("wrong opmode %u", vap->iv_opmode));
1881
1882 if (st->st_newscan) {
1883 sta_update_notseen(st);
1884 st->st_newscan = 0;
1885 }
1886 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1887 /*
1888 * Manual/background scan, don't select+join the
1889 * bss, just return. The scanning framework will
1890 * handle notification that this has completed.
1891 */
1892 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1893 return 1;
1894 }
1895 /*
1896 * Automatic sequencing; look for a candidate and
1897 * if found join the network.
1898 */
1899 /* NB: unlocked read should be ok */
1900 if (TAILQ_FIRST(&st->st_entry) == NULL) {
1901 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1902 "%s: no scan candidate\n", __func__);
1903 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1904 return 0;
1905 notfound:
1906 if (ms->ms_idlen != 0) {
1907 /*
1908 * No existing mbss network to join and we have
1909 * a meshid; start one up. If no channel was
1910 * specified, try to select a channel.
1911 */
1912 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC ||
1913 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
1914 struct ieee80211com *ic = vap->iv_ic;
1915
1916 /* XXX VHT */
1917 chan = adhoc_pick_channel(ss, 0);
1918 if (chan != NULL) {
1919 chan = ieee80211_ht_adjust_channel(ic,
1920 chan, vap->iv_flags_ht);
1921 chan = ieee80211_vht_adjust_channel(ic,
1922 chan, vap->iv_flags_vht);
1923 }
1924 } else
1925 chan = vap->iv_des_chan;
1926 if (chan != NULL) {
1927 ieee80211_create_ibss(vap, chan);
1928 return 1;
1929 }
1930 }
1931 /*
1932 * If nothing suitable was found decrement
1933 * the failure counts so entries will be
1934 * reconsidered the next time around. We
1935 * really want to do this only for sta's
1936 * where we've previously had some success.
1937 */
1938 sta_dec_fails(st);
1939 st->st_newscan = 1;
1940 return 0; /* restart scan */
1941 }
1942 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1943 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1944 return (selbs != NULL);
1945 if (selbs == NULL)
1946 goto notfound;
1947 chan = selbs->base.se_chan;
1948 if (selbs->se_flags & STA_DEMOTE11B)
1949 chan = demote11b(vap, chan);
1950 if (!ieee80211_sta_join(vap, chan, &selbs->base))
1951 goto notfound;
1952 return 1; /* terminate scan */
1953 }
1954
1955 static const struct ieee80211_scanner mesh_default = {
1956 .scan_name = "default",
1957 .scan_attach = sta_attach,
1958 .scan_detach = sta_detach,
1959 .scan_start = adhoc_start,
1960 .scan_restart = sta_restart,
1961 .scan_cancel = sta_cancel,
1962 .scan_end = mesh_pick_bss,
1963 .scan_flush = sta_flush,
1964 .scan_pickchan = adhoc_pick_channel,
1965 .scan_add = sta_add,
1966 .scan_age = adhoc_age,
1967 .scan_iterate = sta_iterate,
1968 .scan_assoc_fail = sta_assoc_fail,
1969 .scan_assoc_success = sta_assoc_success,
1970 };
1971 IEEE80211_SCANNER_ALG(mesh, IEEE80211_M_MBSS, mesh_default);
1972 #endif /* IEEE80211_SUPPORT_MESH */
Cache object: 341b44c42f526c0a301c64c143b951ef
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