1 /*-
2 * Copyright (c) 2002-2009 Sam Leffler, Errno Consulting
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD: releng/10.3/sys/net80211/ieee80211_scan_sta.c 254315 2013-08-14 04:24:25Z rpaulo $");
28
29 /*
30 * IEEE 802.11 station scanning support.
31 */
32 #include "opt_wlan.h"
33
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/module.h>
38
39 #include <sys/socket.h>
40
41 #include <net/if.h>
42 #include <net/if_media.h>
43 #include <net/ethernet.h>
44
45 #include <net80211/ieee80211_var.h>
46 #include <net80211/ieee80211_input.h>
47 #include <net80211/ieee80211_regdomain.h>
48 #ifdef IEEE80211_SUPPORT_TDMA
49 #include <net80211/ieee80211_tdma.h>
50 #endif
51 #ifdef IEEE80211_SUPPORT_MESH
52 #include <net80211/ieee80211_mesh.h>
53 #endif
54 #include <net80211/ieee80211_ratectl.h>
55
56 #include <net/bpf.h>
57
58 /*
59 * Parameters for managing cache entries:
60 *
61 * o a station with STA_FAILS_MAX failures is not considered
62 * when picking a candidate
63 * o a station that hasn't had an update in STA_PURGE_SCANS
64 * (background) scans is discarded
65 * o after STA_FAILS_AGE seconds we clear the failure count
66 */
67 #define STA_FAILS_MAX 2 /* assoc failures before ignored */
68 #define STA_FAILS_AGE (2*60) /* time before clearing fails (secs) */
69 #define STA_PURGE_SCANS 2 /* age for purging entries (scans) */
70
71 /* XXX tunable */
72 #define STA_RSSI_MIN 8 /* min acceptable rssi */
73 #define STA_RSSI_MAX 40 /* max rssi for comparison */
74
75 struct sta_entry {
76 struct ieee80211_scan_entry base;
77 TAILQ_ENTRY(sta_entry) se_list;
78 LIST_ENTRY(sta_entry) se_hash;
79 uint8_t se_fails; /* failure to associate count */
80 uint8_t se_seen; /* seen during current scan */
81 uint8_t se_notseen; /* not seen in previous scans */
82 uint8_t se_flags;
83 #define STA_DEMOTE11B 0x01 /* match w/ demoted 11b chan */
84 uint32_t se_avgrssi; /* LPF rssi state */
85 unsigned long se_lastupdate; /* time of last update */
86 unsigned long se_lastfail; /* time of last failure */
87 unsigned long se_lastassoc; /* time of last association */
88 u_int se_scangen; /* iterator scan gen# */
89 u_int se_countrygen; /* gen# of last cc notify */
90 };
91
92 #define STA_HASHSIZE 32
93 /* simple hash is enough for variation of macaddr */
94 #define STA_HASH(addr) \
95 (((const uint8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % STA_HASHSIZE)
96
97 #define MAX_IEEE_CHAN 256 /* max acceptable IEEE chan # */
98 CTASSERT(MAX_IEEE_CHAN >= 256);
99
100 struct sta_table {
101 ieee80211_scan_table_lock_t st_lock; /* on scan table */
102 TAILQ_HEAD(, sta_entry) st_entry; /* all entries */
103 LIST_HEAD(, sta_entry) st_hash[STA_HASHSIZE];
104 struct mtx st_scanlock; /* on st_scaniter */
105 u_int st_scaniter; /* gen# for iterator */
106 u_int st_scangen; /* scan generation # */
107 int st_newscan;
108 /* ap-related state */
109 int st_maxrssi[MAX_IEEE_CHAN];
110 };
111
112 static void sta_flush_table(struct sta_table *);
113 /*
114 * match_bss returns a bitmask describing if an entry is suitable
115 * for use. If non-zero the entry was deemed not suitable and it's
116 * contents explains why. The following flags are or'd to to this
117 * mask and can be used to figure out why the entry was rejected.
118 */
119 #define MATCH_CHANNEL 0x00001 /* channel mismatch */
120 #define MATCH_CAPINFO 0x00002 /* capabilities mismatch, e.g. no ess */
121 #define MATCH_PRIVACY 0x00004 /* privacy mismatch */
122 #define MATCH_RATE 0x00008 /* rate set mismatch */
123 #define MATCH_SSID 0x00010 /* ssid mismatch */
124 #define MATCH_BSSID 0x00020 /* bssid mismatch */
125 #define MATCH_FAILS 0x00040 /* too many failed auth attempts */
126 #define MATCH_NOTSEEN 0x00080 /* not seen in recent scans */
127 #define MATCH_RSSI 0x00100 /* rssi deemed too low to use */
128 #define MATCH_CC 0x00200 /* country code mismatch */
129 #define MATCH_TDMA_NOIE 0x00400 /* no TDMA ie */
130 #define MATCH_TDMA_NOTMASTER 0x00800 /* not TDMA master */
131 #define MATCH_TDMA_NOSLOT 0x01000 /* all TDMA slots occupied */
132 #define MATCH_TDMA_LOCAL 0x02000 /* local address */
133 #define MATCH_TDMA_VERSION 0x04000 /* protocol version mismatch */
134 #define MATCH_MESH_NOID 0x10000 /* no MESHID ie */
135 #define MATCH_MESHID 0x20000 /* meshid mismatch */
136 static int match_bss(struct ieee80211vap *,
137 const struct ieee80211_scan_state *, struct sta_entry *, int);
138 static void adhoc_age(struct ieee80211_scan_state *);
139
140 static __inline int
141 isocmp(const uint8_t cc1[], const uint8_t cc2[])
142 {
143 return (cc1[0] == cc2[0] && cc1[1] == cc2[1]);
144 }
145
146 /* number of references from net80211 layer */
147 static int nrefs = 0;
148 /*
149 * Module glue.
150 */
151 IEEE80211_SCANNER_MODULE(sta, 1);
152
153 /*
154 * Attach prior to any scanning work.
155 */
156 static int
157 sta_attach(struct ieee80211_scan_state *ss)
158 {
159 struct sta_table *st;
160
161 st = (struct sta_table *) malloc(sizeof(struct sta_table),
162 M_80211_SCAN, M_NOWAIT | M_ZERO);
163 if (st == NULL)
164 return 0;
165 IEEE80211_SCAN_TABLE_LOCK_INIT(st, "scantable");
166 mtx_init(&st->st_scanlock, "scangen", "802.11 scangen", MTX_DEF);
167 TAILQ_INIT(&st->st_entry);
168 ss->ss_priv = st;
169 nrefs++; /* NB: we assume caller locking */
170 return 1;
171 }
172
173 /*
174 * Cleanup any private state.
175 */
176 static int
177 sta_detach(struct ieee80211_scan_state *ss)
178 {
179 struct sta_table *st = ss->ss_priv;
180
181 if (st != NULL) {
182 sta_flush_table(st);
183 IEEE80211_SCAN_TABLE_LOCK_DESTROY(st);
184 mtx_destroy(&st->st_scanlock);
185 free(st, M_80211_SCAN);
186 KASSERT(nrefs > 0, ("imbalanced attach/detach"));
187 nrefs--; /* NB: we assume caller locking */
188 }
189 return 1;
190 }
191
192 /*
193 * Flush all per-scan state.
194 */
195 static int
196 sta_flush(struct ieee80211_scan_state *ss)
197 {
198 struct sta_table *st = ss->ss_priv;
199
200 IEEE80211_SCAN_TABLE_LOCK(st);
201 sta_flush_table(st);
202 IEEE80211_SCAN_TABLE_UNLOCK(st);
203 ss->ss_last = 0;
204 return 0;
205 }
206
207 /*
208 * Flush all entries in the scan cache.
209 */
210 static void
211 sta_flush_table(struct sta_table *st)
212 {
213 struct sta_entry *se, *next;
214
215 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) {
216 TAILQ_REMOVE(&st->st_entry, se, se_list);
217 LIST_REMOVE(se, se_hash);
218 ieee80211_ies_cleanup(&se->base.se_ies);
219 free(se, M_80211_SCAN);
220 }
221 memset(st->st_maxrssi, 0, sizeof(st->st_maxrssi));
222 }
223
224 /*
225 * Process a beacon or probe response frame; create an
226 * entry in the scan cache or update any previous entry.
227 */
228 static int
229 sta_add(struct ieee80211_scan_state *ss,
230 const struct ieee80211_scanparams *sp,
231 const struct ieee80211_frame *wh,
232 int subtype, int rssi, int noise)
233 {
234 #define ISPROBE(_st) ((_st) == IEEE80211_FC0_SUBTYPE_PROBE_RESP)
235 #define PICK1ST(_ss) \
236 ((ss->ss_flags & (IEEE80211_SCAN_PICK1ST | IEEE80211_SCAN_GOTPICK)) == \
237 IEEE80211_SCAN_PICK1ST)
238 struct sta_table *st = ss->ss_priv;
239 const uint8_t *macaddr = wh->i_addr2;
240 struct ieee80211vap *vap = ss->ss_vap;
241 struct ieee80211com *ic = vap->iv_ic;
242 struct ieee80211_channel *c;
243 struct sta_entry *se;
244 struct ieee80211_scan_entry *ise;
245 int hash;
246
247 hash = STA_HASH(macaddr);
248
249 IEEE80211_SCAN_TABLE_LOCK(st);
250 LIST_FOREACH(se, &st->st_hash[hash], se_hash)
251 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr))
252 goto found;
253 se = (struct sta_entry *) malloc(sizeof(struct sta_entry),
254 M_80211_SCAN, M_NOWAIT | M_ZERO);
255 if (se == NULL) {
256 IEEE80211_SCAN_TABLE_UNLOCK(st);
257 return 0;
258 }
259 se->se_scangen = st->st_scaniter-1;
260 se->se_avgrssi = IEEE80211_RSSI_DUMMY_MARKER;
261 IEEE80211_ADDR_COPY(se->base.se_macaddr, macaddr);
262 TAILQ_INSERT_TAIL(&st->st_entry, se, se_list);
263 LIST_INSERT_HEAD(&st->st_hash[hash], se, se_hash);
264 found:
265 ise = &se->base;
266 /* XXX ap beaconing multiple ssid w/ same bssid */
267 if (sp->ssid[1] != 0 &&
268 (ISPROBE(subtype) || ise->se_ssid[1] == 0))
269 memcpy(ise->se_ssid, sp->ssid, 2+sp->ssid[1]);
270 KASSERT(sp->rates[1] <= IEEE80211_RATE_MAXSIZE,
271 ("rate set too large: %u", sp->rates[1]));
272 memcpy(ise->se_rates, sp->rates, 2+sp->rates[1]);
273 if (sp->xrates != NULL) {
274 /* XXX validate xrates[1] */
275 KASSERT(sp->xrates[1] <= IEEE80211_RATE_MAXSIZE,
276 ("xrate set too large: %u", sp->xrates[1]));
277 memcpy(ise->se_xrates, sp->xrates, 2+sp->xrates[1]);
278 } else
279 ise->se_xrates[1] = 0;
280 IEEE80211_ADDR_COPY(ise->se_bssid, wh->i_addr3);
281 if ((sp->status & IEEE80211_BPARSE_OFFCHAN) == 0) {
282 /*
283 * Record rssi data using extended precision LPF filter.
284 *
285 * NB: use only on-channel data to insure we get a good
286 * estimate of the signal we'll see when associated.
287 */
288 IEEE80211_RSSI_LPF(se->se_avgrssi, rssi);
289 ise->se_rssi = IEEE80211_RSSI_GET(se->se_avgrssi);
290 ise->se_noise = noise;
291 }
292 memcpy(ise->se_tstamp.data, sp->tstamp, sizeof(ise->se_tstamp));
293 ise->se_intval = sp->bintval;
294 ise->se_capinfo = sp->capinfo;
295 #ifdef IEEE80211_SUPPORT_MESH
296 if (sp->meshid != NULL && sp->meshid[1] != 0)
297 memcpy(ise->se_meshid, sp->meshid, 2+sp->meshid[1]);
298 #endif
299 /*
300 * Beware of overriding se_chan for frames seen
301 * off-channel; this can cause us to attempt an
302 * association on the wrong channel.
303 */
304 if (sp->status & IEEE80211_BPARSE_OFFCHAN) {
305 /*
306 * Off-channel, locate the home/bss channel for the sta
307 * using the value broadcast in the DSPARMS ie. We know
308 * sp->chan has this value because it's used to calculate
309 * IEEE80211_BPARSE_OFFCHAN.
310 */
311 c = ieee80211_find_channel_byieee(ic, sp->chan,
312 ic->ic_curchan->ic_flags);
313 if (c != NULL) {
314 ise->se_chan = c;
315 } else if (ise->se_chan == NULL) {
316 /* should not happen, pick something */
317 ise->se_chan = ic->ic_curchan;
318 }
319 } else
320 ise->se_chan = ic->ic_curchan;
321 if (IEEE80211_IS_CHAN_HT(ise->se_chan) && sp->htcap == NULL) {
322 /* Demote legacy networks to a non-HT channel. */
323 c = ieee80211_find_channel(ic, ise->se_chan->ic_freq,
324 ise->se_chan->ic_flags & ~IEEE80211_CHAN_HT);
325 KASSERT(c != NULL,
326 ("no legacy channel %u", ise->se_chan->ic_ieee));
327 ise->se_chan = c;
328 }
329 ise->se_fhdwell = sp->fhdwell;
330 ise->se_fhindex = sp->fhindex;
331 ise->se_erp = sp->erp;
332 ise->se_timoff = sp->timoff;
333 if (sp->tim != NULL) {
334 const struct ieee80211_tim_ie *tim =
335 (const struct ieee80211_tim_ie *) sp->tim;
336 ise->se_dtimperiod = tim->tim_period;
337 }
338 if (sp->country != NULL) {
339 const struct ieee80211_country_ie *cie =
340 (const struct ieee80211_country_ie *) sp->country;
341 /*
342 * If 11d is enabled and we're attempting to join a bss
343 * that advertises it's country code then compare our
344 * current settings to what we fetched from the country ie.
345 * If our country code is unspecified or different then
346 * dispatch an event to user space that identifies the
347 * country code so our regdomain config can be changed.
348 */
349 /* XXX only for STA mode? */
350 if ((IEEE80211_IS_CHAN_11D(ise->se_chan) ||
351 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) &&
352 (ic->ic_regdomain.country == CTRY_DEFAULT ||
353 !isocmp(cie->cc, ic->ic_regdomain.isocc))) {
354 /* only issue one notify event per scan */
355 if (se->se_countrygen != st->st_scangen) {
356 ieee80211_notify_country(vap, ise->se_bssid,
357 cie->cc);
358 se->se_countrygen = st->st_scangen;
359 }
360 }
361 ise->se_cc[0] = cie->cc[0];
362 ise->se_cc[1] = cie->cc[1];
363 }
364 /* NB: no need to setup ie ptrs; they are not (currently) used */
365 (void) ieee80211_ies_init(&ise->se_ies, sp->ies, sp->ies_len);
366
367 /* clear failure count after STA_FAIL_AGE passes */
368 if (se->se_fails && (ticks - se->se_lastfail) > STA_FAILS_AGE*hz) {
369 se->se_fails = 0;
370 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, macaddr,
371 "%s: fails %u", __func__, se->se_fails);
372 }
373
374 se->se_lastupdate = ticks; /* update time */
375 se->se_seen = 1;
376 se->se_notseen = 0;
377
378 KASSERT(sizeof(sp->bchan) == 1, ("bchan size"));
379 if (rssi > st->st_maxrssi[sp->bchan])
380 st->st_maxrssi[sp->bchan] = rssi;
381
382 IEEE80211_SCAN_TABLE_UNLOCK(st);
383
384 /*
385 * If looking for a quick choice and nothing's
386 * been found check here.
387 */
388 if (PICK1ST(ss) && match_bss(vap, ss, se, IEEE80211_MSG_SCAN) == 0)
389 ss->ss_flags |= IEEE80211_SCAN_GOTPICK;
390
391 return 1;
392 #undef PICK1ST
393 #undef ISPROBE
394 }
395
396 /*
397 * Check if a channel is excluded by user request.
398 */
399 static int
400 isexcluded(struct ieee80211vap *vap, const struct ieee80211_channel *c)
401 {
402 return (isclr(vap->iv_ic->ic_chan_active, c->ic_ieee) ||
403 (vap->iv_des_chan != IEEE80211_CHAN_ANYC &&
404 c->ic_freq != vap->iv_des_chan->ic_freq));
405 }
406
407 static struct ieee80211_channel *
408 find11gchannel(struct ieee80211com *ic, int i, int freq)
409 {
410 struct ieee80211_channel *c;
411 int j;
412
413 /*
414 * The normal ordering in the channel list is b channel
415 * immediately followed by g so optimize the search for
416 * this. We'll still do a full search just in case.
417 */
418 for (j = i+1; j < ic->ic_nchans; j++) {
419 c = &ic->ic_channels[j];
420 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c))
421 return c;
422 }
423 for (j = 0; j < i; j++) {
424 c = &ic->ic_channels[j];
425 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c))
426 return c;
427 }
428 return NULL;
429 }
430
431 static const u_int chanflags[IEEE80211_MODE_MAX] = {
432 [IEEE80211_MODE_AUTO] = IEEE80211_CHAN_B,
433 [IEEE80211_MODE_11A] = IEEE80211_CHAN_A,
434 [IEEE80211_MODE_11B] = IEEE80211_CHAN_B,
435 [IEEE80211_MODE_11G] = IEEE80211_CHAN_G,
436 [IEEE80211_MODE_FH] = IEEE80211_CHAN_FHSS,
437 /* check base channel */
438 [IEEE80211_MODE_TURBO_A] = IEEE80211_CHAN_A,
439 [IEEE80211_MODE_TURBO_G] = IEEE80211_CHAN_G,
440 [IEEE80211_MODE_STURBO_A] = IEEE80211_CHAN_ST,
441 [IEEE80211_MODE_HALF] = IEEE80211_CHAN_HALF,
442 [IEEE80211_MODE_QUARTER] = IEEE80211_CHAN_QUARTER,
443 /* check legacy */
444 [IEEE80211_MODE_11NA] = IEEE80211_CHAN_A,
445 [IEEE80211_MODE_11NG] = IEEE80211_CHAN_G,
446 };
447
448 static void
449 add_channels(struct ieee80211vap *vap,
450 struct ieee80211_scan_state *ss,
451 enum ieee80211_phymode mode, const uint16_t freq[], int nfreq)
452 {
453 struct ieee80211com *ic = vap->iv_ic;
454 struct ieee80211_channel *c, *cg;
455 u_int modeflags;
456 int i;
457
458 KASSERT(mode < nitems(chanflags), ("Unexpected mode %u", mode));
459 modeflags = chanflags[mode];
460 for (i = 0; i < nfreq; i++) {
461 if (ss->ss_last >= IEEE80211_SCAN_MAX)
462 break;
463
464 c = ieee80211_find_channel(ic, freq[i], modeflags);
465 if (c == NULL || isexcluded(vap, c))
466 continue;
467 if (mode == IEEE80211_MODE_AUTO) {
468 /*
469 * XXX special-case 11b/g channels so we select
470 * the g channel if both are present.
471 */
472 if (IEEE80211_IS_CHAN_B(c) &&
473 (cg = find11gchannel(ic, i, c->ic_freq)) != NULL)
474 c = cg;
475 }
476 ss->ss_chans[ss->ss_last++] = c;
477 }
478 }
479
480 struct scanlist {
481 uint16_t mode;
482 uint16_t count;
483 const uint16_t *list;
484 };
485
486 static int
487 checktable(const struct scanlist *scan, const struct ieee80211_channel *c)
488 {
489 int i;
490
491 for (; scan->list != NULL; scan++) {
492 for (i = 0; i < scan->count; i++)
493 if (scan->list[i] == c->ic_freq)
494 return 1;
495 }
496 return 0;
497 }
498
499 static int
500 onscanlist(const struct ieee80211_scan_state *ss,
501 const struct ieee80211_channel *c)
502 {
503 int i;
504
505 for (i = 0; i < ss->ss_last; i++)
506 if (ss->ss_chans[i] == c)
507 return 1;
508 return 0;
509 }
510
511 static void
512 sweepchannels(struct ieee80211_scan_state *ss, struct ieee80211vap *vap,
513 const struct scanlist table[])
514 {
515 struct ieee80211com *ic = vap->iv_ic;
516 struct ieee80211_channel *c;
517 int i;
518
519 for (i = 0; i < ic->ic_nchans; i++) {
520 if (ss->ss_last >= IEEE80211_SCAN_MAX)
521 break;
522
523 c = &ic->ic_channels[i];
524 /*
525 * Ignore dynamic turbo channels; we scan them
526 * in normal mode (i.e. not boosted). Likewise
527 * for HT channels, they get scanned using
528 * legacy rates.
529 */
530 if (IEEE80211_IS_CHAN_DTURBO(c) || IEEE80211_IS_CHAN_HT(c))
531 continue;
532
533 /*
534 * If a desired mode was specified, scan only
535 * channels that satisfy that constraint.
536 */
537 if (vap->iv_des_mode != IEEE80211_MODE_AUTO &&
538 vap->iv_des_mode != ieee80211_chan2mode(c))
539 continue;
540
541 /*
542 * Skip channels excluded by user request.
543 */
544 if (isexcluded(vap, c))
545 continue;
546
547 /*
548 * Add the channel unless it is listed in the
549 * fixed scan order tables. This insures we
550 * don't sweep back in channels we filtered out
551 * above.
552 */
553 if (checktable(table, c))
554 continue;
555
556 /* Add channel to scanning list. */
557 ss->ss_chans[ss->ss_last++] = c;
558 }
559 /*
560 * Explicitly add any desired channel if:
561 * - not already on the scan list
562 * - allowed by any desired mode constraint
563 * - there is space in the scan list
564 * This allows the channel to be used when the filtering
565 * mechanisms would otherwise elide it (e.g HT, turbo).
566 */
567 c = vap->iv_des_chan;
568 if (c != IEEE80211_CHAN_ANYC &&
569 !onscanlist(ss, c) &&
570 (vap->iv_des_mode == IEEE80211_MODE_AUTO ||
571 vap->iv_des_mode == ieee80211_chan2mode(c)) &&
572 ss->ss_last < IEEE80211_SCAN_MAX)
573 ss->ss_chans[ss->ss_last++] = c;
574 }
575
576 static void
577 makescanlist(struct ieee80211_scan_state *ss, struct ieee80211vap *vap,
578 const struct scanlist table[])
579 {
580 const struct scanlist *scan;
581 enum ieee80211_phymode mode;
582
583 ss->ss_last = 0;
584 /*
585 * Use the table of ordered channels to construct the list
586 * of channels for scanning. Any channels in the ordered
587 * list not in the master list will be discarded.
588 */
589 for (scan = table; scan->list != NULL; scan++) {
590 mode = scan->mode;
591 if (vap->iv_des_mode != IEEE80211_MODE_AUTO) {
592 /*
593 * If a desired mode was specified, scan only
594 * channels that satisfy that constraint.
595 */
596 if (vap->iv_des_mode != mode) {
597 /*
598 * The scan table marks 2.4Ghz channels as b
599 * so if the desired mode is 11g, then use
600 * the 11b channel list but upgrade the mode.
601 */
602 if (vap->iv_des_mode != IEEE80211_MODE_11G ||
603 mode != IEEE80211_MODE_11B)
604 continue;
605 mode = IEEE80211_MODE_11G; /* upgrade */
606 }
607 } else {
608 /*
609 * This lets add_channels upgrade an 11b channel
610 * to 11g if available.
611 */
612 if (mode == IEEE80211_MODE_11B)
613 mode = IEEE80211_MODE_AUTO;
614 }
615 #ifdef IEEE80211_F_XR
616 /* XR does not operate on turbo channels */
617 if ((vap->iv_flags & IEEE80211_F_XR) &&
618 (mode == IEEE80211_MODE_TURBO_A ||
619 mode == IEEE80211_MODE_TURBO_G ||
620 mode == IEEE80211_MODE_STURBO_A))
621 continue;
622 #endif
623 /*
624 * Add the list of the channels; any that are not
625 * in the master channel list will be discarded.
626 */
627 add_channels(vap, ss, mode, scan->list, scan->count);
628 }
629
630 /*
631 * Add the channels from the ic that are not present
632 * in the table.
633 */
634 sweepchannels(ss, vap, table);
635 }
636
637 static const uint16_t rcl1[] = /* 8 FCC channel: 52, 56, 60, 64, 36, 40, 44, 48 */
638 { 5260, 5280, 5300, 5320, 5180, 5200, 5220, 5240 };
639 static const uint16_t rcl2[] = /* 4 MKK channels: 34, 38, 42, 46 */
640 { 5170, 5190, 5210, 5230 };
641 static const uint16_t rcl3[] = /* 2.4Ghz ch: 1,6,11,7,13 */
642 { 2412, 2437, 2462, 2442, 2472 };
643 static const uint16_t rcl4[] = /* 5 FCC channel: 149, 153, 161, 165 */
644 { 5745, 5765, 5785, 5805, 5825 };
645 static const uint16_t rcl7[] = /* 11 ETSI channel: 100,104,108,112,116,120,124,128,132,136,140 */
646 { 5500, 5520, 5540, 5560, 5580, 5600, 5620, 5640, 5660, 5680, 5700 };
647 static const uint16_t rcl8[] = /* 2.4Ghz ch: 2,3,4,5,8,9,10,12 */
648 { 2417, 2422, 2427, 2432, 2447, 2452, 2457, 2467 };
649 static const uint16_t rcl9[] = /* 2.4Ghz ch: 14 */
650 { 2484 };
651 static const uint16_t rcl10[] = /* Added Korean channels 2312-2372 */
652 { 2312, 2317, 2322, 2327, 2332, 2337, 2342, 2347, 2352, 2357, 2362, 2367, 2372 };
653 static const uint16_t rcl11[] = /* Added Japan channels in 4.9/5.0 spectrum */
654 { 5040, 5060, 5080, 4920, 4940, 4960, 4980 };
655 #ifdef ATH_TURBO_SCAN
656 static const uint16_t rcl5[] = /* 3 static turbo channels */
657 { 5210, 5250, 5290 };
658 static const uint16_t rcl6[] = /* 2 static turbo channels */
659 { 5760, 5800 };
660 static const uint16_t rcl6x[] = /* 4 FCC3 turbo channels */
661 { 5540, 5580, 5620, 5660 };
662 static const uint16_t rcl12[] = /* 2.4Ghz Turbo channel 6 */
663 { 2437 };
664 static const uint16_t rcl13[] = /* dynamic Turbo channels */
665 { 5200, 5240, 5280, 5765, 5805 };
666 #endif /* ATH_TURBO_SCAN */
667
668 #define X(a) .count = sizeof(a)/sizeof(a[0]), .list = a
669
670 static const struct scanlist staScanTable[] = {
671 { IEEE80211_MODE_11B, X(rcl3) },
672 { IEEE80211_MODE_11A, X(rcl1) },
673 { IEEE80211_MODE_11A, X(rcl2) },
674 { IEEE80211_MODE_11B, X(rcl8) },
675 { IEEE80211_MODE_11B, X(rcl9) },
676 { IEEE80211_MODE_11A, X(rcl4) },
677 #ifdef ATH_TURBO_SCAN
678 { IEEE80211_MODE_STURBO_A, X(rcl5) },
679 { IEEE80211_MODE_STURBO_A, X(rcl6) },
680 { IEEE80211_MODE_TURBO_A, X(rcl6x) },
681 { IEEE80211_MODE_TURBO_A, X(rcl13) },
682 #endif /* ATH_TURBO_SCAN */
683 { IEEE80211_MODE_11A, X(rcl7) },
684 { IEEE80211_MODE_11B, X(rcl10) },
685 { IEEE80211_MODE_11A, X(rcl11) },
686 #ifdef ATH_TURBO_SCAN
687 { IEEE80211_MODE_TURBO_G, X(rcl12) },
688 #endif /* ATH_TURBO_SCAN */
689 { .list = NULL }
690 };
691
692 /*
693 * Start a station-mode scan by populating the channel list.
694 */
695 static int
696 sta_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
697 {
698 struct sta_table *st = ss->ss_priv;
699
700 makescanlist(ss, vap, staScanTable);
701
702 if (ss->ss_mindwell == 0)
703 ss->ss_mindwell = msecs_to_ticks(20); /* 20ms */
704 if (ss->ss_maxdwell == 0)
705 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
706
707 st->st_scangen++;
708 st->st_newscan = 1;
709
710 return 0;
711 }
712
713 /*
714 * Restart a scan, typically a bg scan but can
715 * also be a fg scan that came up empty.
716 */
717 static int
718 sta_restart(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
719 {
720 struct sta_table *st = ss->ss_priv;
721
722 st->st_newscan = 1;
723 return 0;
724 }
725
726 /*
727 * Cancel an ongoing scan.
728 */
729 static int
730 sta_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
731 {
732 return 0;
733 }
734
735 /* unalligned little endian access */
736 #define LE_READ_2(p) \
737 ((uint16_t) \
738 ((((const uint8_t *)(p))[0] ) | \
739 (((const uint8_t *)(p))[1] << 8)))
740
741 /*
742 * Demote any supplied 11g channel to 11b. There should
743 * always be an 11b channel but we check anyway...
744 */
745 static struct ieee80211_channel *
746 demote11b(struct ieee80211vap *vap, struct ieee80211_channel *chan)
747 {
748 struct ieee80211_channel *c;
749
750 if (IEEE80211_IS_CHAN_ANYG(chan) &&
751 vap->iv_des_mode == IEEE80211_MODE_AUTO) {
752 c = ieee80211_find_channel(vap->iv_ic, chan->ic_freq,
753 (chan->ic_flags &~ (IEEE80211_CHAN_PUREG | IEEE80211_CHAN_G)) |
754 IEEE80211_CHAN_B);
755 if (c != NULL)
756 chan = c;
757 }
758 return chan;
759 }
760
761 static int
762 maxrate(const struct ieee80211_scan_entry *se)
763 {
764 const struct ieee80211_ie_htcap *htcap =
765 (const struct ieee80211_ie_htcap *) se->se_ies.htcap_ie;
766 int rmax, r, i, txstream;
767 uint16_t caps;
768 uint8_t txparams;
769
770 rmax = 0;
771 if (htcap != NULL) {
772 /*
773 * HT station; inspect supported MCS and then adjust
774 * rate by channel width.
775 */
776 txparams = htcap->hc_mcsset[12];
777 if (txparams & 0x3) {
778 /*
779 * TX MCS parameters defined and not equal to RX,
780 * extract the number of spartial streams and
781 * map it to the highest MCS rate.
782 */
783 txstream = ((txparams & 0xc) >> 2) + 1;
784 i = txstream * 8 - 1;
785 } else
786 for (i = 31; i >= 0 && isclr(htcap->hc_mcsset, i); i--);
787 if (i >= 0) {
788 caps = LE_READ_2(&htcap->hc_cap);
789 if ((caps & IEEE80211_HTCAP_CHWIDTH40) &&
790 (caps & IEEE80211_HTCAP_SHORTGI40))
791 rmax = ieee80211_htrates[i].ht40_rate_400ns;
792 else if (caps & IEEE80211_HTCAP_CHWIDTH40)
793 rmax = ieee80211_htrates[i].ht40_rate_800ns;
794 else if (caps & IEEE80211_HTCAP_SHORTGI20)
795 rmax = ieee80211_htrates[i].ht20_rate_400ns;
796 else
797 rmax = ieee80211_htrates[i].ht20_rate_800ns;
798 }
799 }
800 for (i = 0; i < se->se_rates[1]; i++) {
801 r = se->se_rates[2+i] & IEEE80211_RATE_VAL;
802 if (r > rmax)
803 rmax = r;
804 }
805 for (i = 0; i < se->se_xrates[1]; i++) {
806 r = se->se_xrates[2+i] & IEEE80211_RATE_VAL;
807 if (r > rmax)
808 rmax = r;
809 }
810 return rmax;
811 }
812
813 /*
814 * Compare the capabilities of two entries and decide which is
815 * more desirable (return >0 if a is considered better). Note
816 * that we assume compatibility/usability has already been checked
817 * so we don't need to (e.g. validate whether privacy is supported).
818 * Used to select the best scan candidate for association in a BSS.
819 */
820 static int
821 sta_compare(const struct sta_entry *a, const struct sta_entry *b)
822 {
823 #define PREFER(_a,_b,_what) do { \
824 if (((_a) ^ (_b)) & (_what)) \
825 return ((_a) & (_what)) ? 1 : -1; \
826 } while (0)
827 int maxa, maxb;
828 int8_t rssia, rssib;
829 int weight;
830
831 /* privacy support */
832 PREFER(a->base.se_capinfo, b->base.se_capinfo,
833 IEEE80211_CAPINFO_PRIVACY);
834
835 /* compare count of previous failures */
836 weight = b->se_fails - a->se_fails;
837 if (abs(weight) > 1)
838 return weight;
839
840 /*
841 * Compare rssi. If the two are considered equivalent
842 * then fallback to other criteria. We threshold the
843 * comparisons to avoid selecting an ap purely by rssi
844 * when both values may be good but one ap is otherwise
845 * more desirable (e.g. an 11b-only ap with stronger
846 * signal than an 11g ap).
847 */
848 rssia = MIN(a->base.se_rssi, STA_RSSI_MAX);
849 rssib = MIN(b->base.se_rssi, STA_RSSI_MAX);
850 if (abs(rssib - rssia) < 5) {
851 /* best/max rate preferred if signal level close enough XXX */
852 maxa = maxrate(&a->base);
853 maxb = maxrate(&b->base);
854 if (maxa != maxb)
855 return maxa - maxb;
856 /* XXX use freq for channel preference */
857 /* for now just prefer 5Ghz band to all other bands */
858 PREFER(IEEE80211_IS_CHAN_5GHZ(a->base.se_chan),
859 IEEE80211_IS_CHAN_5GHZ(b->base.se_chan), 1);
860 }
861 /* all things being equal, use signal level */
862 return a->base.se_rssi - b->base.se_rssi;
863 #undef PREFER
864 }
865
866 /*
867 * Check rate set suitability and return the best supported rate.
868 * XXX inspect MCS for HT
869 */
870 static int
871 check_rate(struct ieee80211vap *vap, const struct ieee80211_channel *chan,
872 const struct ieee80211_scan_entry *se)
873 {
874 #define RV(v) ((v) & IEEE80211_RATE_VAL)
875 const struct ieee80211_rateset *srs;
876 int i, j, nrs, r, okrate, badrate, fixedrate, ucastrate;
877 const uint8_t *rs;
878
879 okrate = badrate = 0;
880
881 srs = ieee80211_get_suprates(vap->iv_ic, chan);
882 nrs = se->se_rates[1];
883 rs = se->se_rates+2;
884 /* XXX MCS */
885 ucastrate = vap->iv_txparms[ieee80211_chan2mode(chan)].ucastrate;
886 fixedrate = IEEE80211_FIXED_RATE_NONE;
887 again:
888 for (i = 0; i < nrs; i++) {
889 r = RV(rs[i]);
890 badrate = r;
891 /*
892 * Check any fixed rate is included.
893 */
894 if (r == ucastrate)
895 fixedrate = r;
896 /*
897 * Check against our supported rates.
898 */
899 for (j = 0; j < srs->rs_nrates; j++)
900 if (r == RV(srs->rs_rates[j])) {
901 if (r > okrate) /* NB: track max */
902 okrate = r;
903 break;
904 }
905
906 if (j == srs->rs_nrates && (rs[i] & IEEE80211_RATE_BASIC)) {
907 /*
908 * Don't try joining a BSS, if we don't support
909 * one of its basic rates.
910 */
911 okrate = 0;
912 goto back;
913 }
914 }
915 if (rs == se->se_rates+2) {
916 /* scan xrates too; sort of an algol68-style for loop */
917 nrs = se->se_xrates[1];
918 rs = se->se_xrates+2;
919 goto again;
920 }
921
922 back:
923 if (okrate == 0 || ucastrate != fixedrate)
924 return badrate | IEEE80211_RATE_BASIC;
925 else
926 return RV(okrate);
927 #undef RV
928 }
929
930 static __inline int
931 match_id(const uint8_t *ie, const uint8_t *val, int len)
932 {
933 return (ie[1] == len && memcmp(ie+2, val, len) == 0);
934 }
935
936 static int
937 match_ssid(const uint8_t *ie,
938 int nssid, const struct ieee80211_scan_ssid ssids[])
939 {
940 int i;
941
942 for (i = 0; i < nssid; i++) {
943 if (match_id(ie, ssids[i].ssid, ssids[i].len))
944 return 1;
945 }
946 return 0;
947 }
948
949 #ifdef IEEE80211_SUPPORT_TDMA
950 static int
951 tdma_isfull(const struct ieee80211_tdma_param *tdma)
952 {
953 int slot, slotcnt;
954
955 slotcnt = tdma->tdma_slotcnt;
956 for (slot = slotcnt-1; slot >= 0; slot--)
957 if (isclr(tdma->tdma_inuse, slot))
958 return 0;
959 return 1;
960 }
961 #endif /* IEEE80211_SUPPORT_TDMA */
962
963 /*
964 * Test a scan candidate for suitability/compatibility.
965 */
966 static int
967 match_bss(struct ieee80211vap *vap,
968 const struct ieee80211_scan_state *ss, struct sta_entry *se0,
969 int debug)
970 {
971 struct ieee80211com *ic = vap->iv_ic;
972 struct ieee80211_scan_entry *se = &se0->base;
973 uint8_t rate;
974 int fail;
975
976 fail = 0;
977 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, se->se_chan)))
978 fail |= MATCH_CHANNEL;
979 /*
980 * NB: normally the desired mode is used to construct
981 * the channel list, but it's possible for the scan
982 * cache to include entries for stations outside this
983 * list so we check the desired mode here to weed them
984 * out.
985 */
986 if (vap->iv_des_mode != IEEE80211_MODE_AUTO &&
987 (se->se_chan->ic_flags & IEEE80211_CHAN_ALLTURBO) !=
988 chanflags[vap->iv_des_mode])
989 fail |= MATCH_CHANNEL;
990 if (vap->iv_opmode == IEEE80211_M_IBSS) {
991 if ((se->se_capinfo & IEEE80211_CAPINFO_IBSS) == 0)
992 fail |= MATCH_CAPINFO;
993 #ifdef IEEE80211_SUPPORT_TDMA
994 } else if (vap->iv_opmode == IEEE80211_M_AHDEMO) {
995 /*
996 * Adhoc demo network setup shouldn't really be scanning
997 * but just in case skip stations operating in IBSS or
998 * BSS mode.
999 */
1000 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS))
1001 fail |= MATCH_CAPINFO;
1002 /*
1003 * TDMA operation cannot coexist with a normal 802.11 network;
1004 * skip if IBSS or ESS capabilities are marked and require
1005 * the beacon have a TDMA ie present.
1006 */
1007 if (vap->iv_caps & IEEE80211_C_TDMA) {
1008 const struct ieee80211_tdma_param *tdma =
1009 (const struct ieee80211_tdma_param *)se->se_ies.tdma_ie;
1010 const struct ieee80211_tdma_state *ts = vap->iv_tdma;
1011
1012 if (tdma == NULL)
1013 fail |= MATCH_TDMA_NOIE;
1014 else if (tdma->tdma_version != ts->tdma_version)
1015 fail |= MATCH_TDMA_VERSION;
1016 else if (tdma->tdma_slot != 0)
1017 fail |= MATCH_TDMA_NOTMASTER;
1018 else if (tdma_isfull(tdma))
1019 fail |= MATCH_TDMA_NOSLOT;
1020 #if 0
1021 else if (ieee80211_local_address(se->se_macaddr))
1022 fail |= MATCH_TDMA_LOCAL;
1023 #endif
1024 }
1025 #endif /* IEEE80211_SUPPORT_TDMA */
1026 #ifdef IEEE80211_SUPPORT_MESH
1027 } else if (vap->iv_opmode == IEEE80211_M_MBSS) {
1028 const struct ieee80211_mesh_state *ms = vap->iv_mesh;
1029 /*
1030 * Mesh nodes have IBSS & ESS bits in capinfo turned off
1031 * and two special ie's that must be present.
1032 */
1033 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS))
1034 fail |= MATCH_CAPINFO;
1035 else if (se->se_meshid[0] != IEEE80211_ELEMID_MESHID)
1036 fail |= MATCH_MESH_NOID;
1037 else if (ms->ms_idlen != 0 &&
1038 match_id(se->se_meshid, ms->ms_id, ms->ms_idlen))
1039 fail |= MATCH_MESHID;
1040 #endif
1041 } else {
1042 if ((se->se_capinfo & IEEE80211_CAPINFO_ESS) == 0)
1043 fail |= MATCH_CAPINFO;
1044 /*
1045 * If 11d is enabled and we're attempting to join a bss
1046 * that advertises it's country code then compare our
1047 * current settings to what we fetched from the country ie.
1048 * If our country code is unspecified or different then do
1049 * not attempt to join the bss. We should have already
1050 * dispatched an event to user space that identifies the
1051 * new country code so our regdomain config should match.
1052 */
1053 if ((IEEE80211_IS_CHAN_11D(se->se_chan) ||
1054 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) &&
1055 se->se_cc[0] != 0 &&
1056 (ic->ic_regdomain.country == CTRY_DEFAULT ||
1057 !isocmp(se->se_cc, ic->ic_regdomain.isocc)))
1058 fail |= MATCH_CC;
1059 }
1060 if (vap->iv_flags & IEEE80211_F_PRIVACY) {
1061 if ((se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0)
1062 fail |= MATCH_PRIVACY;
1063 } else {
1064 /* XXX does this mean privacy is supported or required? */
1065 if (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY)
1066 fail |= MATCH_PRIVACY;
1067 }
1068 se0->se_flags &= ~STA_DEMOTE11B;
1069 rate = check_rate(vap, se->se_chan, se);
1070 if (rate & IEEE80211_RATE_BASIC) {
1071 fail |= MATCH_RATE;
1072 /*
1073 * An 11b-only ap will give a rate mismatch if there is an
1074 * OFDM fixed tx rate for 11g. Try downgrading the channel
1075 * in the scan list to 11b and retry the rate check.
1076 */
1077 if (IEEE80211_IS_CHAN_ANYG(se->se_chan)) {
1078 rate = check_rate(vap, demote11b(vap, se->se_chan), se);
1079 if ((rate & IEEE80211_RATE_BASIC) == 0) {
1080 fail &= ~MATCH_RATE;
1081 se0->se_flags |= STA_DEMOTE11B;
1082 }
1083 }
1084 } else if (rate < 2*24) {
1085 /*
1086 * This is an 11b-only ap. Check the desired mode in
1087 * case that needs to be honored (mode 11g filters out
1088 * 11b-only ap's). Otherwise force any 11g channel used
1089 * in scanning to be demoted.
1090 *
1091 * NB: we cheat a bit here by looking at the max rate;
1092 * we could/should check the rates.
1093 */
1094 if (!(vap->iv_des_mode == IEEE80211_MODE_AUTO ||
1095 vap->iv_des_mode == IEEE80211_MODE_11B))
1096 fail |= MATCH_RATE;
1097 else
1098 se0->se_flags |= STA_DEMOTE11B;
1099 }
1100 if (ss->ss_nssid != 0 &&
1101 !match_ssid(se->se_ssid, ss->ss_nssid, ss->ss_ssid))
1102 fail |= MATCH_SSID;
1103 if ((vap->iv_flags & IEEE80211_F_DESBSSID) &&
1104 !IEEE80211_ADDR_EQ(vap->iv_des_bssid, se->se_bssid))
1105 fail |= MATCH_BSSID;
1106 if (se0->se_fails >= STA_FAILS_MAX)
1107 fail |= MATCH_FAILS;
1108 if (se0->se_notseen >= STA_PURGE_SCANS)
1109 fail |= MATCH_NOTSEEN;
1110 if (se->se_rssi < STA_RSSI_MIN)
1111 fail |= MATCH_RSSI;
1112 #ifdef IEEE80211_DEBUG
1113 if (ieee80211_msg(vap, debug)) {
1114 printf(" %c %s",
1115 fail & MATCH_FAILS ? '=' :
1116 fail & MATCH_NOTSEEN ? '^' :
1117 fail & MATCH_CC ? '$' :
1118 #ifdef IEEE80211_SUPPORT_TDMA
1119 fail & MATCH_TDMA_NOIE ? '&' :
1120 fail & MATCH_TDMA_VERSION ? 'v' :
1121 fail & MATCH_TDMA_NOTMASTER ? 's' :
1122 fail & MATCH_TDMA_NOSLOT ? 'f' :
1123 fail & MATCH_TDMA_LOCAL ? 'l' :
1124 #endif
1125 fail & MATCH_MESH_NOID ? 'm' :
1126 fail ? '-' : '+', ether_sprintf(se->se_macaddr));
1127 printf(" %s%c", ether_sprintf(se->se_bssid),
1128 fail & MATCH_BSSID ? '!' : ' ');
1129 printf(" %3d%c", ieee80211_chan2ieee(ic, se->se_chan),
1130 fail & MATCH_CHANNEL ? '!' : ' ');
1131 printf(" %+4d%c", se->se_rssi, fail & MATCH_RSSI ? '!' : ' ');
1132 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2,
1133 fail & MATCH_RATE ? '!' : ' ');
1134 printf(" %4s%c",
1135 (se->se_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" :
1136 (se->se_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : "",
1137 fail & MATCH_CAPINFO ? '!' : ' ');
1138 printf(" %3s%c ",
1139 (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) ?
1140 "wep" : "no",
1141 fail & MATCH_PRIVACY ? '!' : ' ');
1142 ieee80211_print_essid(se->se_ssid+2, se->se_ssid[1]);
1143 printf("%s\n", fail & (MATCH_SSID | MATCH_MESHID) ? "!" : "");
1144 }
1145 #endif
1146 return fail;
1147 }
1148
1149 static void
1150 sta_update_notseen(struct sta_table *st)
1151 {
1152 struct sta_entry *se;
1153
1154 IEEE80211_SCAN_TABLE_LOCK(st);
1155 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1156 /*
1157 * If seen the reset and don't bump the count;
1158 * otherwise bump the ``not seen'' count. Note
1159 * that this insures that stations for which we
1160 * see frames while not scanning but not during
1161 * this scan will not be penalized.
1162 */
1163 if (se->se_seen)
1164 se->se_seen = 0;
1165 else
1166 se->se_notseen++;
1167 }
1168 IEEE80211_SCAN_TABLE_UNLOCK(st);
1169 }
1170
1171 static void
1172 sta_dec_fails(struct sta_table *st)
1173 {
1174 struct sta_entry *se;
1175
1176 IEEE80211_SCAN_TABLE_LOCK(st);
1177 TAILQ_FOREACH(se, &st->st_entry, se_list)
1178 if (se->se_fails)
1179 se->se_fails--;
1180 IEEE80211_SCAN_TABLE_UNLOCK(st);
1181 }
1182
1183 static struct sta_entry *
1184 select_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, int debug)
1185 {
1186 struct sta_table *st = ss->ss_priv;
1187 struct sta_entry *se, *selbs = NULL;
1188
1189 IEEE80211_DPRINTF(vap, debug, " %s\n",
1190 "macaddr bssid chan rssi rate flag wep essid");
1191 IEEE80211_SCAN_TABLE_LOCK(st);
1192 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1193 ieee80211_ies_expand(&se->base.se_ies);
1194 if (match_bss(vap, ss, se, debug) == 0) {
1195 if (selbs == NULL)
1196 selbs = se;
1197 else if (sta_compare(se, selbs) > 0)
1198 selbs = se;
1199 }
1200 }
1201 IEEE80211_SCAN_TABLE_UNLOCK(st);
1202
1203 return selbs;
1204 }
1205
1206 /*
1207 * Pick an ap or ibss network to join or find a channel
1208 * to use to start an ibss network.
1209 */
1210 static int
1211 sta_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1212 {
1213 struct sta_table *st = ss->ss_priv;
1214 struct sta_entry *selbs;
1215 struct ieee80211_channel *chan;
1216
1217 KASSERT(vap->iv_opmode == IEEE80211_M_STA,
1218 ("wrong mode %u", vap->iv_opmode));
1219
1220 if (st->st_newscan) {
1221 sta_update_notseen(st);
1222 st->st_newscan = 0;
1223 }
1224 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1225 /*
1226 * Manual/background scan, don't select+join the
1227 * bss, just return. The scanning framework will
1228 * handle notification that this has completed.
1229 */
1230 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1231 return 1;
1232 }
1233 /*
1234 * Automatic sequencing; look for a candidate and
1235 * if found join the network.
1236 */
1237 /* NB: unlocked read should be ok */
1238 if (TAILQ_FIRST(&st->st_entry) == NULL) {
1239 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1240 "%s: no scan candidate\n", __func__);
1241 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1242 return 0;
1243 notfound:
1244 /*
1245 * If nothing suitable was found decrement
1246 * the failure counts so entries will be
1247 * reconsidered the next time around. We
1248 * really want to do this only for sta's
1249 * where we've previously had some success.
1250 */
1251 sta_dec_fails(st);
1252 st->st_newscan = 1;
1253 return 0; /* restart scan */
1254 }
1255 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1256 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1257 return (selbs != NULL);
1258 if (selbs == NULL)
1259 goto notfound;
1260 chan = selbs->base.se_chan;
1261 if (selbs->se_flags & STA_DEMOTE11B)
1262 chan = demote11b(vap, chan);
1263 if (!ieee80211_sta_join(vap, chan, &selbs->base))
1264 goto notfound;
1265 return 1; /* terminate scan */
1266 }
1267
1268 /*
1269 * Lookup an entry in the scan cache. We assume we're
1270 * called from the bottom half or such that we don't need
1271 * to block the bottom half so that it's safe to return
1272 * a reference to an entry w/o holding the lock on the table.
1273 */
1274 static struct sta_entry *
1275 sta_lookup(struct sta_table *st, const uint8_t macaddr[IEEE80211_ADDR_LEN])
1276 {
1277 struct sta_entry *se;
1278 int hash = STA_HASH(macaddr);
1279
1280 IEEE80211_SCAN_TABLE_LOCK(st);
1281 LIST_FOREACH(se, &st->st_hash[hash], se_hash)
1282 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr))
1283 break;
1284 IEEE80211_SCAN_TABLE_UNLOCK(st);
1285
1286 return se; /* NB: unlocked */
1287 }
1288
1289 static void
1290 sta_roam_check(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1291 {
1292 struct ieee80211com *ic = vap->iv_ic;
1293 struct ieee80211_node *ni = vap->iv_bss;
1294 struct sta_table *st = ss->ss_priv;
1295 enum ieee80211_phymode mode;
1296 struct sta_entry *se, *selbs;
1297 uint8_t roamRate, curRate, ucastRate;
1298 int8_t roamRssi, curRssi;
1299
1300 se = sta_lookup(st, ni->ni_macaddr);
1301 if (se == NULL) {
1302 /* XXX something is wrong */
1303 return;
1304 }
1305
1306 mode = ieee80211_chan2mode(ic->ic_bsschan);
1307 roamRate = vap->iv_roamparms[mode].rate;
1308 roamRssi = vap->iv_roamparms[mode].rssi;
1309 ucastRate = vap->iv_txparms[mode].ucastrate;
1310 /* NB: the most up to date rssi is in the node, not the scan cache */
1311 curRssi = ic->ic_node_getrssi(ni);
1312 if (ucastRate == IEEE80211_FIXED_RATE_NONE) {
1313 curRate = ni->ni_txrate;
1314 roamRate &= IEEE80211_RATE_VAL;
1315 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM,
1316 "%s: currssi %d currate %u roamrssi %d roamrate %u\n",
1317 __func__, curRssi, curRate, roamRssi, roamRate);
1318 } else {
1319 curRate = roamRate; /* NB: insure compare below fails */
1320 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM,
1321 "%s: currssi %d roamrssi %d\n", __func__, curRssi, roamRssi);
1322 }
1323 /*
1324 * Check if a new ap should be used and switch.
1325 * XXX deauth current ap
1326 */
1327 if (curRate < roamRate || curRssi < roamRssi) {
1328 if (time_after(ticks, ic->ic_lastscan + vap->iv_scanvalid)) {
1329 /*
1330 * Scan cache contents are too old; force a scan now
1331 * if possible so we have current state to make a
1332 * decision with. We don't kick off a bg scan if
1333 * we're using dynamic turbo and boosted or if the
1334 * channel is busy.
1335 * XXX force immediate switch on scan complete
1336 */
1337 if (!IEEE80211_IS_CHAN_DTURBO(ic->ic_curchan) &&
1338 time_after(ticks, ic->ic_lastdata + vap->iv_bgscanidle))
1339 ieee80211_bg_scan(vap, 0);
1340 return;
1341 }
1342 se->base.se_rssi = curRssi;
1343 selbs = select_bss(ss, vap, IEEE80211_MSG_ROAM);
1344 if (selbs != NULL && selbs != se) {
1345 struct ieee80211_channel *chan;
1346
1347 IEEE80211_DPRINTF(vap,
1348 IEEE80211_MSG_ROAM | IEEE80211_MSG_DEBUG,
1349 "%s: ROAM: curRate %u, roamRate %u, "
1350 "curRssi %d, roamRssi %d\n", __func__,
1351 curRate, roamRate, curRssi, roamRssi);
1352
1353 chan = selbs->base.se_chan;
1354 if (selbs->se_flags & STA_DEMOTE11B)
1355 chan = demote11b(vap, chan);
1356 (void) ieee80211_sta_join(vap, chan, &selbs->base);
1357 }
1358 }
1359 }
1360
1361 /*
1362 * Age entries in the scan cache.
1363 * XXX also do roaming since it's convenient
1364 */
1365 static void
1366 sta_age(struct ieee80211_scan_state *ss)
1367 {
1368 struct ieee80211vap *vap = ss->ss_vap;
1369
1370 adhoc_age(ss);
1371 /*
1372 * If rate control is enabled check periodically to see if
1373 * we should roam from our current connection to one that
1374 * might be better. This only applies when we're operating
1375 * in sta mode and automatic roaming is set.
1376 * XXX defer if busy
1377 * XXX repeater station
1378 * XXX do when !bgscan?
1379 */
1380 KASSERT(vap->iv_opmode == IEEE80211_M_STA,
1381 ("wrong mode %u", vap->iv_opmode));
1382 if (vap->iv_roaming == IEEE80211_ROAMING_AUTO &&
1383 (vap->iv_flags & IEEE80211_F_BGSCAN) &&
1384 vap->iv_state >= IEEE80211_S_RUN)
1385 /* XXX vap is implicit */
1386 sta_roam_check(ss, vap);
1387 }
1388
1389 /*
1390 * Iterate over the entries in the scan cache, invoking
1391 * the callback function on each one.
1392 */
1393 static void
1394 sta_iterate(struct ieee80211_scan_state *ss,
1395 ieee80211_scan_iter_func *f, void *arg)
1396 {
1397 struct sta_table *st = ss->ss_priv;
1398 struct sta_entry *se;
1399 u_int gen;
1400
1401 mtx_lock(&st->st_scanlock);
1402 gen = st->st_scaniter++;
1403 restart:
1404 IEEE80211_SCAN_TABLE_LOCK(st);
1405 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1406 if (se->se_scangen != gen) {
1407 se->se_scangen = gen;
1408 /* update public state */
1409 se->base.se_age = ticks - se->se_lastupdate;
1410 IEEE80211_SCAN_TABLE_UNLOCK(st);
1411 (*f)(arg, &se->base);
1412 goto restart;
1413 }
1414 }
1415 IEEE80211_SCAN_TABLE_UNLOCK(st);
1416
1417 mtx_unlock(&st->st_scanlock);
1418 }
1419
1420 static void
1421 sta_assoc_fail(struct ieee80211_scan_state *ss,
1422 const uint8_t macaddr[IEEE80211_ADDR_LEN], int reason)
1423 {
1424 struct sta_table *st = ss->ss_priv;
1425 struct sta_entry *se;
1426
1427 se = sta_lookup(st, macaddr);
1428 if (se != NULL) {
1429 se->se_fails++;
1430 se->se_lastfail = ticks;
1431 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN,
1432 macaddr, "%s: reason %u fails %u",
1433 __func__, reason, se->se_fails);
1434 }
1435 }
1436
1437 static void
1438 sta_assoc_success(struct ieee80211_scan_state *ss,
1439 const uint8_t macaddr[IEEE80211_ADDR_LEN])
1440 {
1441 struct sta_table *st = ss->ss_priv;
1442 struct sta_entry *se;
1443
1444 se = sta_lookup(st, macaddr);
1445 if (se != NULL) {
1446 #if 0
1447 se->se_fails = 0;
1448 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN,
1449 macaddr, "%s: fails %u",
1450 __func__, se->se_fails);
1451 #endif
1452 se->se_lastassoc = ticks;
1453 }
1454 }
1455
1456 static const struct ieee80211_scanner sta_default = {
1457 .scan_name = "default",
1458 .scan_attach = sta_attach,
1459 .scan_detach = sta_detach,
1460 .scan_start = sta_start,
1461 .scan_restart = sta_restart,
1462 .scan_cancel = sta_cancel,
1463 .scan_end = sta_pick_bss,
1464 .scan_flush = sta_flush,
1465 .scan_add = sta_add,
1466 .scan_age = sta_age,
1467 .scan_iterate = sta_iterate,
1468 .scan_assoc_fail = sta_assoc_fail,
1469 .scan_assoc_success = sta_assoc_success,
1470 };
1471 IEEE80211_SCANNER_ALG(sta, IEEE80211_M_STA, sta_default);
1472
1473 /*
1474 * Adhoc mode-specific support.
1475 */
1476
1477 static const uint16_t adhocWorld[] = /* 36, 40, 44, 48 */
1478 { 5180, 5200, 5220, 5240 };
1479 static const uint16_t adhocFcc3[] = /* 36, 40, 44, 48 145, 149, 153, 157, 161, 165 */
1480 { 5180, 5200, 5220, 5240, 5725, 5745, 5765, 5785, 5805, 5825 };
1481 static const uint16_t adhocMkk[] = /* 34, 38, 42, 46 */
1482 { 5170, 5190, 5210, 5230 };
1483 static const uint16_t adhoc11b[] = /* 10, 11 */
1484 { 2457, 2462 };
1485
1486 static const struct scanlist adhocScanTable[] = {
1487 { IEEE80211_MODE_11B, X(adhoc11b) },
1488 { IEEE80211_MODE_11A, X(adhocWorld) },
1489 { IEEE80211_MODE_11A, X(adhocFcc3) },
1490 { IEEE80211_MODE_11B, X(adhocMkk) },
1491 { .list = NULL }
1492 };
1493 #undef X
1494
1495 /*
1496 * Start an adhoc-mode scan by populating the channel list.
1497 */
1498 static int
1499 adhoc_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1500 {
1501 struct sta_table *st = ss->ss_priv;
1502
1503 makescanlist(ss, vap, adhocScanTable);
1504
1505 if (ss->ss_mindwell == 0)
1506 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */
1507 if (ss->ss_maxdwell == 0)
1508 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
1509
1510 st->st_scangen++;
1511 st->st_newscan = 1;
1512
1513 return 0;
1514 }
1515
1516 /*
1517 * Select a channel to start an adhoc network on.
1518 * The channel list was populated with appropriate
1519 * channels so select one that looks least occupied.
1520 */
1521 static struct ieee80211_channel *
1522 adhoc_pick_channel(struct ieee80211_scan_state *ss, int flags)
1523 {
1524 struct sta_table *st = ss->ss_priv;
1525 struct sta_entry *se;
1526 struct ieee80211_channel *c, *bestchan;
1527 int i, bestrssi, maxrssi;
1528
1529 bestchan = NULL;
1530 bestrssi = -1;
1531
1532 IEEE80211_SCAN_TABLE_LOCK(st);
1533 for (i = 0; i < ss->ss_last; i++) {
1534 c = ss->ss_chans[i];
1535 /* never consider a channel with radar */
1536 if (IEEE80211_IS_CHAN_RADAR(c))
1537 continue;
1538 /* skip channels disallowed by regulatory settings */
1539 if (IEEE80211_IS_CHAN_NOADHOC(c))
1540 continue;
1541 /* check channel attributes for band compatibility */
1542 if (flags != 0 && (c->ic_flags & flags) != flags)
1543 continue;
1544 maxrssi = 0;
1545 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1546 if (se->base.se_chan != c)
1547 continue;
1548 if (se->base.se_rssi > maxrssi)
1549 maxrssi = se->base.se_rssi;
1550 }
1551 if (bestchan == NULL || maxrssi < bestrssi)
1552 bestchan = c;
1553 }
1554 IEEE80211_SCAN_TABLE_UNLOCK(st);
1555
1556 return bestchan;
1557 }
1558
1559 /*
1560 * Pick an ibss network to join or find a channel
1561 * to use to start an ibss network.
1562 */
1563 static int
1564 adhoc_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1565 {
1566 struct sta_table *st = ss->ss_priv;
1567 struct sta_entry *selbs;
1568 struct ieee80211_channel *chan;
1569 struct ieee80211com *ic = vap->iv_ic;
1570
1571 KASSERT(vap->iv_opmode == IEEE80211_M_IBSS ||
1572 vap->iv_opmode == IEEE80211_M_AHDEMO ||
1573 vap->iv_opmode == IEEE80211_M_MBSS,
1574 ("wrong opmode %u", vap->iv_opmode));
1575
1576 if (st->st_newscan) {
1577 sta_update_notseen(st);
1578 st->st_newscan = 0;
1579 }
1580 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1581 /*
1582 * Manual/background scan, don't select+join the
1583 * bss, just return. The scanning framework will
1584 * handle notification that this has completed.
1585 */
1586 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1587 return 1;
1588 }
1589 /*
1590 * Automatic sequencing; look for a candidate and
1591 * if found join the network.
1592 */
1593 /* NB: unlocked read should be ok */
1594 if (TAILQ_FIRST(&st->st_entry) == NULL) {
1595 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1596 "%s: no scan candidate\n", __func__);
1597 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1598 return 0;
1599 notfound:
1600 /* NB: never auto-start a tdma network for slot !0 */
1601 #ifdef IEEE80211_SUPPORT_TDMA
1602 if (vap->iv_des_nssid &&
1603 ((vap->iv_caps & IEEE80211_C_TDMA) == 0 ||
1604 ieee80211_tdma_getslot(vap) == 0)) {
1605 #else
1606 if (vap->iv_des_nssid) {
1607 #endif
1608 /*
1609 * No existing adhoc network to join and we have
1610 * an ssid; start one up. If no channel was
1611 * specified, try to select a channel.
1612 */
1613 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC ||
1614 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
1615 chan = adhoc_pick_channel(ss, 0);
1616 } else
1617 chan = vap->iv_des_chan;
1618 if (chan != NULL) {
1619 struct ieee80211com *ic = vap->iv_ic;
1620 /*
1621 * Create a HT capable IBSS; the per-node
1622 * probe request/response will result in
1623 * "correct" rate control capabilities being
1624 * negotiated.
1625 */
1626 chan = ieee80211_ht_adjust_channel(ic,
1627 chan, vap->iv_flags_ht);
1628 ieee80211_create_ibss(vap, chan);
1629 return 1;
1630 }
1631 }
1632 /*
1633 * If nothing suitable was found decrement
1634 * the failure counts so entries will be
1635 * reconsidered the next time around. We
1636 * really want to do this only for sta's
1637 * where we've previously had some success.
1638 */
1639 sta_dec_fails(st);
1640 st->st_newscan = 1;
1641 return 0; /* restart scan */
1642 }
1643 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1644 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1645 return (selbs != NULL);
1646 if (selbs == NULL)
1647 goto notfound;
1648 chan = selbs->base.se_chan;
1649 if (selbs->se_flags & STA_DEMOTE11B)
1650 chan = demote11b(vap, chan);
1651 /*
1652 * If HT is available, make it a possibility here.
1653 * The intent is to enable HT20/HT40 when joining a non-HT
1654 * IBSS node; we can then advertise HT IEs and speak HT
1655 * to any subsequent nodes that support it.
1656 */
1657 chan = ieee80211_ht_adjust_channel(ic,
1658 chan, vap->iv_flags_ht);
1659 if (!ieee80211_sta_join(vap, chan, &selbs->base))
1660 goto notfound;
1661 return 1; /* terminate scan */
1662 }
1663
1664 /*
1665 * Age entries in the scan cache.
1666 */
1667 static void
1668 adhoc_age(struct ieee80211_scan_state *ss)
1669 {
1670 struct sta_table *st = ss->ss_priv;
1671 struct sta_entry *se, *next;
1672
1673 IEEE80211_SCAN_TABLE_LOCK(st);
1674 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) {
1675 if (se->se_notseen > STA_PURGE_SCANS) {
1676 TAILQ_REMOVE(&st->st_entry, se, se_list);
1677 LIST_REMOVE(se, se_hash);
1678 ieee80211_ies_cleanup(&se->base.se_ies);
1679 free(se, M_80211_SCAN);
1680 }
1681 }
1682 IEEE80211_SCAN_TABLE_UNLOCK(st);
1683 }
1684
1685 static const struct ieee80211_scanner adhoc_default = {
1686 .scan_name = "default",
1687 .scan_attach = sta_attach,
1688 .scan_detach = sta_detach,
1689 .scan_start = adhoc_start,
1690 .scan_restart = sta_restart,
1691 .scan_cancel = sta_cancel,
1692 .scan_end = adhoc_pick_bss,
1693 .scan_flush = sta_flush,
1694 .scan_pickchan = adhoc_pick_channel,
1695 .scan_add = sta_add,
1696 .scan_age = adhoc_age,
1697 .scan_iterate = sta_iterate,
1698 .scan_assoc_fail = sta_assoc_fail,
1699 .scan_assoc_success = sta_assoc_success,
1700 };
1701 IEEE80211_SCANNER_ALG(ibss, IEEE80211_M_IBSS, adhoc_default);
1702 IEEE80211_SCANNER_ALG(ahdemo, IEEE80211_M_AHDEMO, adhoc_default);
1703
1704 static void
1705 ap_force_promisc(struct ieee80211com *ic)
1706 {
1707 struct ifnet *ifp = ic->ic_ifp;
1708
1709 IEEE80211_LOCK(ic);
1710 /* set interface into promiscuous mode */
1711 ifp->if_flags |= IFF_PROMISC;
1712 ieee80211_runtask(ic, &ic->ic_promisc_task);
1713 IEEE80211_UNLOCK(ic);
1714 }
1715
1716 static void
1717 ap_reset_promisc(struct ieee80211com *ic)
1718 {
1719 IEEE80211_LOCK(ic);
1720 ieee80211_syncifflag_locked(ic, IFF_PROMISC);
1721 IEEE80211_UNLOCK(ic);
1722 }
1723
1724 static int
1725 ap_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1726 {
1727 struct sta_table *st = ss->ss_priv;
1728
1729 makescanlist(ss, vap, staScanTable);
1730
1731 if (ss->ss_mindwell == 0)
1732 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */
1733 if (ss->ss_maxdwell == 0)
1734 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
1735
1736 st->st_scangen++;
1737 st->st_newscan = 1;
1738
1739 ap_force_promisc(vap->iv_ic);
1740 return 0;
1741 }
1742
1743 /*
1744 * Cancel an ongoing scan.
1745 */
1746 static int
1747 ap_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1748 {
1749 ap_reset_promisc(vap->iv_ic);
1750 return 0;
1751 }
1752
1753 /*
1754 * Pick a quiet channel to use for ap operation.
1755 */
1756 static struct ieee80211_channel *
1757 ap_pick_channel(struct ieee80211_scan_state *ss, int flags)
1758 {
1759 struct sta_table *st = ss->ss_priv;
1760 struct ieee80211_channel *bestchan = NULL;
1761 int i;
1762
1763 /* XXX select channel more intelligently, e.g. channel spread, power */
1764 /* NB: use scan list order to preserve channel preference */
1765 for (i = 0; i < ss->ss_last; i++) {
1766 struct ieee80211_channel *chan = ss->ss_chans[i];
1767 /*
1768 * If the channel is unoccupied the max rssi
1769 * should be zero; just take it. Otherwise
1770 * track the channel with the lowest rssi and
1771 * use that when all channels appear occupied.
1772 */
1773 if (IEEE80211_IS_CHAN_RADAR(chan))
1774 continue;
1775 if (IEEE80211_IS_CHAN_NOHOSTAP(chan))
1776 continue;
1777 /* check channel attributes for band compatibility */
1778 if (flags != 0 && (chan->ic_flags & flags) != flags)
1779 continue;
1780 KASSERT(sizeof(chan->ic_ieee) == 1, ("ic_chan size"));
1781 /* XXX channel have interference */
1782 if (st->st_maxrssi[chan->ic_ieee] == 0) {
1783 /* XXX use other considerations */
1784 return chan;
1785 }
1786 if (bestchan == NULL ||
1787 st->st_maxrssi[chan->ic_ieee] < st->st_maxrssi[bestchan->ic_ieee])
1788 bestchan = chan;
1789 }
1790 return bestchan;
1791 }
1792
1793 /*
1794 * Pick a quiet channel to use for ap operation.
1795 */
1796 static int
1797 ap_end(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1798 {
1799 struct ieee80211com *ic = vap->iv_ic;
1800 struct ieee80211_channel *bestchan;
1801
1802 KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP,
1803 ("wrong opmode %u", vap->iv_opmode));
1804 bestchan = ap_pick_channel(ss, 0);
1805 if (bestchan == NULL) {
1806 /* no suitable channel, should not happen */
1807 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1808 "%s: no suitable channel! (should not happen)\n", __func__);
1809 /* XXX print something? */
1810 return 0; /* restart scan */
1811 }
1812 /*
1813 * If this is a dynamic turbo channel, start with the unboosted one.
1814 */
1815 if (IEEE80211_IS_CHAN_TURBO(bestchan)) {
1816 bestchan = ieee80211_find_channel(ic, bestchan->ic_freq,
1817 bestchan->ic_flags & ~IEEE80211_CHAN_TURBO);
1818 if (bestchan == NULL) {
1819 /* should never happen ?? */
1820 return 0;
1821 }
1822 }
1823 ap_reset_promisc(ic);
1824 if (ss->ss_flags & (IEEE80211_SCAN_NOPICK | IEEE80211_SCAN_NOJOIN)) {
1825 /*
1826 * Manual/background scan, don't select+join the
1827 * bss, just return. The scanning framework will
1828 * handle notification that this has completed.
1829 */
1830 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1831 return 1;
1832 }
1833 ieee80211_create_ibss(vap,
1834 ieee80211_ht_adjust_channel(ic, bestchan, vap->iv_flags_ht));
1835 return 1;
1836 }
1837
1838 static const struct ieee80211_scanner ap_default = {
1839 .scan_name = "default",
1840 .scan_attach = sta_attach,
1841 .scan_detach = sta_detach,
1842 .scan_start = ap_start,
1843 .scan_restart = sta_restart,
1844 .scan_cancel = ap_cancel,
1845 .scan_end = ap_end,
1846 .scan_flush = sta_flush,
1847 .scan_pickchan = ap_pick_channel,
1848 .scan_add = sta_add,
1849 .scan_age = adhoc_age,
1850 .scan_iterate = sta_iterate,
1851 .scan_assoc_success = sta_assoc_success,
1852 .scan_assoc_fail = sta_assoc_fail,
1853 };
1854 IEEE80211_SCANNER_ALG(ap, IEEE80211_M_HOSTAP, ap_default);
1855
1856 #ifdef IEEE80211_SUPPORT_MESH
1857 /*
1858 * Pick an mbss network to join or find a channel
1859 * to use to start an mbss network.
1860 */
1861 static int
1862 mesh_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1863 {
1864 struct sta_table *st = ss->ss_priv;
1865 struct ieee80211_mesh_state *ms = vap->iv_mesh;
1866 struct sta_entry *selbs;
1867 struct ieee80211_channel *chan;
1868
1869 KASSERT(vap->iv_opmode == IEEE80211_M_MBSS,
1870 ("wrong opmode %u", vap->iv_opmode));
1871
1872 if (st->st_newscan) {
1873 sta_update_notseen(st);
1874 st->st_newscan = 0;
1875 }
1876 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1877 /*
1878 * Manual/background scan, don't select+join the
1879 * bss, just return. The scanning framework will
1880 * handle notification that this has completed.
1881 */
1882 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1883 return 1;
1884 }
1885 /*
1886 * Automatic sequencing; look for a candidate and
1887 * if found join the network.
1888 */
1889 /* NB: unlocked read should be ok */
1890 if (TAILQ_FIRST(&st->st_entry) == NULL) {
1891 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1892 "%s: no scan candidate\n", __func__);
1893 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1894 return 0;
1895 notfound:
1896 if (ms->ms_idlen != 0) {
1897 /*
1898 * No existing mbss network to join and we have
1899 * a meshid; start one up. If no channel was
1900 * specified, try to select a channel.
1901 */
1902 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC ||
1903 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
1904 struct ieee80211com *ic = vap->iv_ic;
1905
1906 chan = adhoc_pick_channel(ss, 0);
1907 if (chan != NULL)
1908 chan = ieee80211_ht_adjust_channel(ic,
1909 chan, vap->iv_flags_ht);
1910 } else
1911 chan = vap->iv_des_chan;
1912 if (chan != NULL) {
1913 ieee80211_create_ibss(vap, chan);
1914 return 1;
1915 }
1916 }
1917 /*
1918 * If nothing suitable was found decrement
1919 * the failure counts so entries will be
1920 * reconsidered the next time around. We
1921 * really want to do this only for sta's
1922 * where we've previously had some success.
1923 */
1924 sta_dec_fails(st);
1925 st->st_newscan = 1;
1926 return 0; /* restart scan */
1927 }
1928 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1929 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1930 return (selbs != NULL);
1931 if (selbs == NULL)
1932 goto notfound;
1933 chan = selbs->base.se_chan;
1934 if (selbs->se_flags & STA_DEMOTE11B)
1935 chan = demote11b(vap, chan);
1936 if (!ieee80211_sta_join(vap, chan, &selbs->base))
1937 goto notfound;
1938 return 1; /* terminate scan */
1939 }
1940
1941 static const struct ieee80211_scanner mesh_default = {
1942 .scan_name = "default",
1943 .scan_attach = sta_attach,
1944 .scan_detach = sta_detach,
1945 .scan_start = adhoc_start,
1946 .scan_restart = sta_restart,
1947 .scan_cancel = sta_cancel,
1948 .scan_end = mesh_pick_bss,
1949 .scan_flush = sta_flush,
1950 .scan_pickchan = adhoc_pick_channel,
1951 .scan_add = sta_add,
1952 .scan_age = adhoc_age,
1953 .scan_iterate = sta_iterate,
1954 .scan_assoc_fail = sta_assoc_fail,
1955 .scan_assoc_success = sta_assoc_success,
1956 };
1957 IEEE80211_SCANNER_ALG(mesh, IEEE80211_M_MBSS, mesh_default);
1958 #endif /* IEEE80211_SUPPORT_MESH */
Cache object: 46b0b81a458a742494f2f67624b36c1e
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