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/8.0/sys/net80211/ieee80211_scan_sta.c 196005 2009-07-31 19:13:16Z sam $");
28
29 /*
30 * IEEE 802.11 station scanning support.
31 */
32 #include "opt_wlan.h"
33
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/module.h>
38
39 #include <sys/socket.h>
40
41 #include <net/if.h>
42 #include <net/if_media.h>
43 #include <net/ethernet.h>
44
45 #include <net80211/ieee80211_var.h>
46 #include <net80211/ieee80211_input.h>
47 #include <net80211/ieee80211_regdomain.h>
48 #ifdef IEEE80211_SUPPORT_TDMA
49 #include <net80211/ieee80211_tdma.h>
50 #endif
51 #ifdef IEEE80211_SUPPORT_MESH
52 #include <net80211/ieee80211_mesh.h>
53 #endif
54
55 #include <net/bpf.h>
56
57 /*
58 * Parameters for managing cache entries:
59 *
60 * o a station with STA_FAILS_MAX failures is not considered
61 * when picking a candidate
62 * o a station that hasn't had an update in STA_PURGE_SCANS
63 * (background) scans is discarded
64 * o after STA_FAILS_AGE seconds we clear the failure count
65 */
66 #define STA_FAILS_MAX 2 /* assoc failures before ignored */
67 #define STA_FAILS_AGE (2*60) /* time before clearing fails (secs) */
68 #define STA_PURGE_SCANS 2 /* age for purging entries (scans) */
69
70 /* XXX tunable */
71 #define STA_RSSI_MIN 8 /* min acceptable rssi */
72 #define STA_RSSI_MAX 40 /* max rssi for comparison */
73
74 struct sta_entry {
75 struct ieee80211_scan_entry base;
76 TAILQ_ENTRY(sta_entry) se_list;
77 LIST_ENTRY(sta_entry) se_hash;
78 uint8_t se_fails; /* failure to associate count */
79 uint8_t se_seen; /* seen during current scan */
80 uint8_t se_notseen; /* not seen in previous scans */
81 uint8_t se_flags;
82 #define STA_DEMOTE11B 0x01 /* match w/ demoted 11b chan */
83 uint32_t se_avgrssi; /* LPF rssi state */
84 unsigned long se_lastupdate; /* time of last update */
85 unsigned long se_lastfail; /* time of last failure */
86 unsigned long se_lastassoc; /* time of last association */
87 u_int se_scangen; /* iterator scan gen# */
88 u_int se_countrygen; /* gen# of last cc notify */
89 };
90
91 #define STA_HASHSIZE 32
92 /* simple hash is enough for variation of macaddr */
93 #define STA_HASH(addr) \
94 (((const uint8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % STA_HASHSIZE)
95
96 #define MAX_IEEE_CHAN 256 /* max acceptable IEEE chan # */
97 CTASSERT(MAX_IEEE_CHAN >= 256);
98
99 struct sta_table {
100 struct mtx st_lock; /* on scan table */
101 TAILQ_HEAD(, sta_entry) st_entry; /* all entries */
102 LIST_HEAD(, sta_entry) st_hash[STA_HASHSIZE];
103 struct mtx st_scanlock; /* on st_scaniter */
104 u_int st_scaniter; /* gen# for iterator */
105 u_int st_scangen; /* scan generation # */
106 int st_newscan;
107 /* ap-related state */
108 int st_maxrssi[MAX_IEEE_CHAN];
109 };
110
111 static void sta_flush_table(struct sta_table *);
112 /*
113 * match_bss returns a bitmask describing if an entry is suitable
114 * for use. If non-zero the entry was deemed not suitable and it's
115 * contents explains why. The following flags are or'd to to this
116 * mask and can be used to figure out why the entry was rejected.
117 */
118 #define MATCH_CHANNEL 0x00001 /* channel mismatch */
119 #define MATCH_CAPINFO 0x00002 /* capabilities mismatch, e.g. no ess */
120 #define MATCH_PRIVACY 0x00004 /* privacy mismatch */
121 #define MATCH_RATE 0x00008 /* rate set mismatch */
122 #define MATCH_SSID 0x00010 /* ssid mismatch */
123 #define MATCH_BSSID 0x00020 /* bssid mismatch */
124 #define MATCH_FAILS 0x00040 /* too many failed auth attempts */
125 #define MATCH_NOTSEEN 0x00080 /* not seen in recent scans */
126 #define MATCH_RSSI 0x00100 /* rssi deemed too low to use */
127 #define MATCH_CC 0x00200 /* country code mismatch */
128 #define MATCH_TDMA_NOIE 0x00400 /* no TDMA ie */
129 #define MATCH_TDMA_NOTMASTER 0x00800 /* not TDMA master */
130 #define MATCH_TDMA_NOSLOT 0x01000 /* all TDMA slots occupied */
131 #define MATCH_TDMA_LOCAL 0x02000 /* local address */
132 #define MATCH_TDMA_VERSION 0x04000 /* protocol version mismatch */
133 #define MATCH_MESH_NOID 0x10000 /* no MESHID ie */
134 #define MATCH_MESHID 0x20000 /* meshid mismatch */
135 static int match_bss(struct ieee80211vap *,
136 const struct ieee80211_scan_state *, struct sta_entry *, int);
137 static void adhoc_age(struct ieee80211_scan_state *);
138
139 static __inline int
140 isocmp(const uint8_t cc1[], const uint8_t cc2[])
141 {
142 return (cc1[0] == cc2[0] && cc1[1] == cc2[1]);
143 }
144
145 /* number of references from net80211 layer */
146 static int nrefs = 0;
147 /*
148 * Module glue.
149 */
150 IEEE80211_SCANNER_MODULE(sta, 1);
151
152 /*
153 * Attach prior to any scanning work.
154 */
155 static int
156 sta_attach(struct ieee80211_scan_state *ss)
157 {
158 struct sta_table *st;
159
160 st = (struct sta_table *) malloc(sizeof(struct sta_table),
161 M_80211_SCAN, M_NOWAIT | M_ZERO);
162 if (st == NULL)
163 return 0;
164 mtx_init(&st->st_lock, "scantable", "802.11 scan table", MTX_DEF);
165 mtx_init(&st->st_scanlock, "scangen", "802.11 scangen", MTX_DEF);
166 TAILQ_INIT(&st->st_entry);
167 ss->ss_priv = st;
168 nrefs++; /* NB: we assume caller locking */
169 return 1;
170 }
171
172 /*
173 * Cleanup any private state.
174 */
175 static int
176 sta_detach(struct ieee80211_scan_state *ss)
177 {
178 struct sta_table *st = ss->ss_priv;
179
180 if (st != NULL) {
181 sta_flush_table(st);
182 mtx_destroy(&st->st_lock);
183 mtx_destroy(&st->st_scanlock);
184 free(st, M_80211_SCAN);
185 KASSERT(nrefs > 0, ("imbalanced attach/detach"));
186 nrefs--; /* NB: we assume caller locking */
187 }
188 return 1;
189 }
190
191 /*
192 * Flush all per-scan state.
193 */
194 static int
195 sta_flush(struct ieee80211_scan_state *ss)
196 {
197 struct sta_table *st = ss->ss_priv;
198
199 mtx_lock(&st->st_lock);
200 sta_flush_table(st);
201 mtx_unlock(&st->st_lock);
202 ss->ss_last = 0;
203 return 0;
204 }
205
206 /*
207 * Flush all entries in the scan cache.
208 */
209 static void
210 sta_flush_table(struct sta_table *st)
211 {
212 struct sta_entry *se, *next;
213
214 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) {
215 TAILQ_REMOVE(&st->st_entry, se, se_list);
216 LIST_REMOVE(se, se_hash);
217 ieee80211_ies_cleanup(&se->base.se_ies);
218 free(se, M_80211_SCAN);
219 }
220 memset(st->st_maxrssi, 0, sizeof(st->st_maxrssi));
221 }
222
223 /*
224 * Process a beacon or probe response frame; create an
225 * entry in the scan cache or update any previous entry.
226 */
227 static int
228 sta_add(struct ieee80211_scan_state *ss,
229 const struct ieee80211_scanparams *sp,
230 const struct ieee80211_frame *wh,
231 int subtype, int rssi, int noise)
232 {
233 #define ISPROBE(_st) ((_st) == IEEE80211_FC0_SUBTYPE_PROBE_RESP)
234 #define PICK1ST(_ss) \
235 ((ss->ss_flags & (IEEE80211_SCAN_PICK1ST | IEEE80211_SCAN_GOTPICK)) == \
236 IEEE80211_SCAN_PICK1ST)
237 struct sta_table *st = ss->ss_priv;
238 const uint8_t *macaddr = wh->i_addr2;
239 struct ieee80211vap *vap = ss->ss_vap;
240 struct ieee80211com *ic = vap->iv_ic;
241 struct sta_entry *se;
242 struct ieee80211_scan_entry *ise;
243 int hash;
244
245 hash = STA_HASH(macaddr);
246
247 mtx_lock(&st->st_lock);
248 LIST_FOREACH(se, &st->st_hash[hash], se_hash)
249 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr))
250 goto found;
251 se = (struct sta_entry *) malloc(sizeof(struct sta_entry),
252 M_80211_SCAN, M_NOWAIT | M_ZERO);
253 if (se == NULL) {
254 mtx_unlock(&st->st_lock);
255 return 0;
256 }
257 se->se_scangen = st->st_scaniter-1;
258 se->se_avgrssi = IEEE80211_RSSI_DUMMY_MARKER;
259 IEEE80211_ADDR_COPY(se->base.se_macaddr, macaddr);
260 TAILQ_INSERT_TAIL(&st->st_entry, se, se_list);
261 LIST_INSERT_HEAD(&st->st_hash[hash], se, se_hash);
262 found:
263 ise = &se->base;
264 /* XXX ap beaconing multiple ssid w/ same bssid */
265 if (sp->ssid[1] != 0 &&
266 (ISPROBE(subtype) || ise->se_ssid[1] == 0))
267 memcpy(ise->se_ssid, sp->ssid, 2+sp->ssid[1]);
268 KASSERT(sp->rates[1] <= IEEE80211_RATE_MAXSIZE,
269 ("rate set too large: %u", sp->rates[1]));
270 memcpy(ise->se_rates, sp->rates, 2+sp->rates[1]);
271 if (sp->xrates != NULL) {
272 /* XXX validate xrates[1] */
273 KASSERT(sp->xrates[1] <= IEEE80211_RATE_MAXSIZE,
274 ("xrate set too large: %u", sp->xrates[1]));
275 memcpy(ise->se_xrates, sp->xrates, 2+sp->xrates[1]);
276 } else
277 ise->se_xrates[1] = 0;
278 IEEE80211_ADDR_COPY(ise->se_bssid, wh->i_addr3);
279 if ((sp->status & IEEE80211_BPARSE_OFFCHAN) == 0) {
280 /*
281 * Record rssi data using extended precision LPF filter.
282 *
283 * NB: use only on-channel data to insure we get a good
284 * estimate of the signal we'll see when associated.
285 */
286 IEEE80211_RSSI_LPF(se->se_avgrssi, rssi);
287 ise->se_rssi = IEEE80211_RSSI_GET(se->se_avgrssi);
288 ise->se_noise = noise;
289 }
290 memcpy(ise->se_tstamp.data, sp->tstamp, sizeof(ise->se_tstamp));
291 ise->se_intval = sp->bintval;
292 ise->se_capinfo = sp->capinfo;
293 #ifdef IEEE80211_SUPPORT_MESH
294 if (sp->meshid != NULL && sp->meshid[1] != 0)
295 memcpy(ise->se_meshid, sp->meshid, 2+sp->meshid[1]);
296 #endif
297 /*
298 * Beware of overriding se_chan for frames seen
299 * off-channel; this can cause us to attempt an
300 * association on the wrong channel.
301 */
302 if (sp->status & IEEE80211_BPARSE_OFFCHAN) {
303 struct ieee80211_channel *c;
304 /*
305 * Off-channel, locate the home/bss channel for the sta
306 * using the value broadcast in the DSPARMS ie. We know
307 * sp->chan has this value because it's used to calculate
308 * IEEE80211_BPARSE_OFFCHAN.
309 */
310 c = ieee80211_find_channel_byieee(ic, sp->chan,
311 ic->ic_curchan->ic_flags);
312 if (c != NULL) {
313 ise->se_chan = c;
314 } else if (ise->se_chan == NULL) {
315 /* should not happen, pick something */
316 ise->se_chan = ic->ic_curchan;
317 }
318 } else
319 ise->se_chan = ic->ic_curchan;
320 ise->se_fhdwell = sp->fhdwell;
321 ise->se_fhindex = sp->fhindex;
322 ise->se_erp = sp->erp;
323 ise->se_timoff = sp->timoff;
324 if (sp->tim != NULL) {
325 const struct ieee80211_tim_ie *tim =
326 (const struct ieee80211_tim_ie *) sp->tim;
327 ise->se_dtimperiod = tim->tim_period;
328 }
329 if (sp->country != NULL) {
330 const struct ieee80211_country_ie *cie =
331 (const struct ieee80211_country_ie *) sp->country;
332 /*
333 * If 11d is enabled and we're attempting to join a bss
334 * that advertises it's country code then compare our
335 * current settings to what we fetched from the country ie.
336 * If our country code is unspecified or different then
337 * dispatch an event to user space that identifies the
338 * country code so our regdomain config can be changed.
339 */
340 /* XXX only for STA mode? */
341 if ((IEEE80211_IS_CHAN_11D(ise->se_chan) ||
342 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) &&
343 (ic->ic_regdomain.country == CTRY_DEFAULT ||
344 !isocmp(cie->cc, ic->ic_regdomain.isocc))) {
345 /* only issue one notify event per scan */
346 if (se->se_countrygen != st->st_scangen) {
347 ieee80211_notify_country(vap, ise->se_bssid,
348 cie->cc);
349 se->se_countrygen = st->st_scangen;
350 }
351 }
352 ise->se_cc[0] = cie->cc[0];
353 ise->se_cc[1] = cie->cc[1];
354 }
355 /* NB: no need to setup ie ptrs; they are not (currently) used */
356 (void) ieee80211_ies_init(&ise->se_ies, sp->ies, sp->ies_len);
357
358 /* clear failure count after STA_FAIL_AGE passes */
359 if (se->se_fails && (ticks - se->se_lastfail) > STA_FAILS_AGE*hz) {
360 se->se_fails = 0;
361 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, macaddr,
362 "%s: fails %u", __func__, se->se_fails);
363 }
364
365 se->se_lastupdate = ticks; /* update time */
366 se->se_seen = 1;
367 se->se_notseen = 0;
368
369 KASSERT(sizeof(sp->bchan) == 1, ("bchan size"));
370 if (rssi > st->st_maxrssi[sp->bchan])
371 st->st_maxrssi[sp->bchan] = rssi;
372
373 mtx_unlock(&st->st_lock);
374
375 /*
376 * If looking for a quick choice and nothing's
377 * been found check here.
378 */
379 if (PICK1ST(ss) && match_bss(vap, ss, se, IEEE80211_MSG_SCAN) == 0)
380 ss->ss_flags |= IEEE80211_SCAN_GOTPICK;
381
382 return 1;
383 #undef PICK1ST
384 #undef ISPROBE
385 }
386
387 /*
388 * Check if a channel is excluded by user request.
389 */
390 static int
391 isexcluded(struct ieee80211vap *vap, const struct ieee80211_channel *c)
392 {
393 return (isclr(vap->iv_ic->ic_chan_active, c->ic_ieee) ||
394 (vap->iv_des_chan != IEEE80211_CHAN_ANYC &&
395 c->ic_freq != vap->iv_des_chan->ic_freq));
396 }
397
398 static struct ieee80211_channel *
399 find11gchannel(struct ieee80211com *ic, int i, int freq)
400 {
401 struct ieee80211_channel *c;
402 int j;
403
404 /*
405 * The normal ordering in the channel list is b channel
406 * immediately followed by g so optimize the search for
407 * this. We'll still do a full search just in case.
408 */
409 for (j = i+1; j < ic->ic_nchans; j++) {
410 c = &ic->ic_channels[j];
411 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c))
412 return c;
413 }
414 for (j = 0; j < i; j++) {
415 c = &ic->ic_channels[j];
416 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c))
417 return c;
418 }
419 return NULL;
420 }
421
422 static const u_int chanflags[IEEE80211_MODE_MAX] = {
423 [IEEE80211_MODE_AUTO] = IEEE80211_CHAN_B,
424 [IEEE80211_MODE_11A] = IEEE80211_CHAN_A,
425 [IEEE80211_MODE_11B] = IEEE80211_CHAN_B,
426 [IEEE80211_MODE_11G] = IEEE80211_CHAN_G,
427 [IEEE80211_MODE_FH] = IEEE80211_CHAN_FHSS,
428 /* check base channel */
429 [IEEE80211_MODE_TURBO_A] = IEEE80211_CHAN_A,
430 [IEEE80211_MODE_TURBO_G] = IEEE80211_CHAN_G,
431 [IEEE80211_MODE_STURBO_A] = IEEE80211_CHAN_ST,
432 [IEEE80211_MODE_HALF] = IEEE80211_CHAN_HALF,
433 [IEEE80211_MODE_QUARTER] = IEEE80211_CHAN_QUARTER,
434 /* check legacy */
435 [IEEE80211_MODE_11NA] = IEEE80211_CHAN_A,
436 [IEEE80211_MODE_11NG] = IEEE80211_CHAN_G,
437 };
438
439 static void
440 add_channels(struct ieee80211vap *vap,
441 struct ieee80211_scan_state *ss,
442 enum ieee80211_phymode mode, const uint16_t freq[], int nfreq)
443 {
444 #define N(a) (sizeof(a) / sizeof(a[0]))
445 struct ieee80211com *ic = vap->iv_ic;
446 struct ieee80211_channel *c, *cg;
447 u_int modeflags;
448 int i;
449
450 KASSERT(mode < N(chanflags), ("Unexpected mode %u", mode));
451 modeflags = chanflags[mode];
452 for (i = 0; i < nfreq; i++) {
453 if (ss->ss_last >= IEEE80211_SCAN_MAX)
454 break;
455
456 c = ieee80211_find_channel(ic, freq[i], modeflags);
457 if (c == NULL || isexcluded(vap, c))
458 continue;
459 if (mode == IEEE80211_MODE_AUTO) {
460 /*
461 * XXX special-case 11b/g channels so we select
462 * the g channel if both are present.
463 */
464 if (IEEE80211_IS_CHAN_B(c) &&
465 (cg = find11gchannel(ic, i, c->ic_freq)) != NULL)
466 c = cg;
467 }
468 ss->ss_chans[ss->ss_last++] = c;
469 }
470 #undef N
471 }
472
473 struct scanlist {
474 uint16_t mode;
475 uint16_t count;
476 const uint16_t *list;
477 };
478
479 static int
480 checktable(const struct scanlist *scan, const struct ieee80211_channel *c)
481 {
482 int i;
483
484 for (; scan->list != NULL; scan++) {
485 for (i = 0; i < scan->count; i++)
486 if (scan->list[i] == c->ic_freq)
487 return 1;
488 }
489 return 0;
490 }
491
492 static int
493 onscanlist(const struct ieee80211_scan_state *ss,
494 const struct ieee80211_channel *c)
495 {
496 int i;
497
498 for (i = 0; i < ss->ss_last; i++)
499 if (ss->ss_chans[i] == c)
500 return 1;
501 return 0;
502 }
503
504 static void
505 sweepchannels(struct ieee80211_scan_state *ss, struct ieee80211vap *vap,
506 const struct scanlist table[])
507 {
508 struct ieee80211com *ic = vap->iv_ic;
509 struct ieee80211_channel *c;
510 int i;
511
512 for (i = 0; i < ic->ic_nchans; i++) {
513 if (ss->ss_last >= IEEE80211_SCAN_MAX)
514 break;
515
516 c = &ic->ic_channels[i];
517 /*
518 * Ignore dynamic turbo channels; we scan them
519 * in normal mode (i.e. not boosted). Likewise
520 * for HT channels, they get scanned using
521 * legacy rates.
522 */
523 if (IEEE80211_IS_CHAN_DTURBO(c) || IEEE80211_IS_CHAN_HT(c))
524 continue;
525
526 /*
527 * If a desired mode was specified, scan only
528 * channels that satisfy that constraint.
529 */
530 if (vap->iv_des_mode != IEEE80211_MODE_AUTO &&
531 vap->iv_des_mode != ieee80211_chan2mode(c))
532 continue;
533
534 /*
535 * Skip channels excluded by user request.
536 */
537 if (isexcluded(vap, c))
538 continue;
539
540 /*
541 * Add the channel unless it is listed in the
542 * fixed scan order tables. This insures we
543 * don't sweep back in channels we filtered out
544 * above.
545 */
546 if (checktable(table, c))
547 continue;
548
549 /* Add channel to scanning list. */
550 ss->ss_chans[ss->ss_last++] = c;
551 }
552 /*
553 * Explicitly add any desired channel if:
554 * - not already on the scan list
555 * - allowed by any desired mode constraint
556 * - there is space in the scan list
557 * This allows the channel to be used when the filtering
558 * mechanisms would otherwise elide it (e.g HT, turbo).
559 */
560 c = vap->iv_des_chan;
561 if (c != IEEE80211_CHAN_ANYC &&
562 !onscanlist(ss, c) &&
563 (vap->iv_des_mode == IEEE80211_MODE_AUTO ||
564 vap->iv_des_mode == ieee80211_chan2mode(c)) &&
565 ss->ss_last < IEEE80211_SCAN_MAX)
566 ss->ss_chans[ss->ss_last++] = c;
567 }
568
569 static void
570 makescanlist(struct ieee80211_scan_state *ss, struct ieee80211vap *vap,
571 const struct scanlist table[])
572 {
573 const struct scanlist *scan;
574 enum ieee80211_phymode mode;
575
576 ss->ss_last = 0;
577 /*
578 * Use the table of ordered channels to construct the list
579 * of channels for scanning. Any channels in the ordered
580 * list not in the master list will be discarded.
581 */
582 for (scan = table; scan->list != NULL; scan++) {
583 mode = scan->mode;
584 if (vap->iv_des_mode != IEEE80211_MODE_AUTO) {
585 /*
586 * If a desired mode was specified, scan only
587 * channels that satisfy that constraint.
588 */
589 if (vap->iv_des_mode != mode) {
590 /*
591 * The scan table marks 2.4Ghz channels as b
592 * so if the desired mode is 11g, then use
593 * the 11b channel list but upgrade the mode.
594 */
595 if (vap->iv_des_mode != IEEE80211_MODE_11G ||
596 mode != IEEE80211_MODE_11B)
597 continue;
598 mode = IEEE80211_MODE_11G; /* upgrade */
599 }
600 } else {
601 /*
602 * This lets add_channels upgrade an 11b channel
603 * to 11g if available.
604 */
605 if (mode == IEEE80211_MODE_11B)
606 mode = IEEE80211_MODE_AUTO;
607 }
608 #ifdef IEEE80211_F_XR
609 /* XR does not operate on turbo channels */
610 if ((vap->iv_flags & IEEE80211_F_XR) &&
611 (mode == IEEE80211_MODE_TURBO_A ||
612 mode == IEEE80211_MODE_TURBO_G ||
613 mode == IEEE80211_MODE_STURBO_A))
614 continue;
615 #endif
616 /*
617 * Add the list of the channels; any that are not
618 * in the master channel list will be discarded.
619 */
620 add_channels(vap, ss, mode, scan->list, scan->count);
621 }
622
623 /*
624 * Add the channels from the ic that are not present
625 * in the table.
626 */
627 sweepchannels(ss, vap, table);
628 }
629
630 static const uint16_t rcl1[] = /* 8 FCC channel: 52, 56, 60, 64, 36, 40, 44, 48 */
631 { 5260, 5280, 5300, 5320, 5180, 5200, 5220, 5240 };
632 static const uint16_t rcl2[] = /* 4 MKK channels: 34, 38, 42, 46 */
633 { 5170, 5190, 5210, 5230 };
634 static const uint16_t rcl3[] = /* 2.4Ghz ch: 1,6,11,7,13 */
635 { 2412, 2437, 2462, 2442, 2472 };
636 static const uint16_t rcl4[] = /* 5 FCC channel: 149, 153, 161, 165 */
637 { 5745, 5765, 5785, 5805, 5825 };
638 static const uint16_t rcl7[] = /* 11 ETSI channel: 100,104,108,112,116,120,124,128,132,136,140 */
639 { 5500, 5520, 5540, 5560, 5580, 5600, 5620, 5640, 5660, 5680, 5700 };
640 static const uint16_t rcl8[] = /* 2.4Ghz ch: 2,3,4,5,8,9,10,12 */
641 { 2417, 2422, 2427, 2432, 2447, 2452, 2457, 2467 };
642 static const uint16_t rcl9[] = /* 2.4Ghz ch: 14 */
643 { 2484 };
644 static const uint16_t rcl10[] = /* Added Korean channels 2312-2372 */
645 { 2312, 2317, 2322, 2327, 2332, 2337, 2342, 2347, 2352, 2357, 2362, 2367, 2372 };
646 static const uint16_t rcl11[] = /* Added Japan channels in 4.9/5.0 spectrum */
647 { 5040, 5060, 5080, 4920, 4940, 4960, 4980 };
648 #ifdef ATH_TURBO_SCAN
649 static const uint16_t rcl5[] = /* 3 static turbo channels */
650 { 5210, 5250, 5290 };
651 static const uint16_t rcl6[] = /* 2 static turbo channels */
652 { 5760, 5800 };
653 static const uint16_t rcl6x[] = /* 4 FCC3 turbo channels */
654 { 5540, 5580, 5620, 5660 };
655 static const uint16_t rcl12[] = /* 2.4Ghz Turbo channel 6 */
656 { 2437 };
657 static const uint16_t rcl13[] = /* dynamic Turbo channels */
658 { 5200, 5240, 5280, 5765, 5805 };
659 #endif /* ATH_TURBO_SCAN */
660
661 #define X(a) .count = sizeof(a)/sizeof(a[0]), .list = a
662
663 static const struct scanlist staScanTable[] = {
664 { IEEE80211_MODE_11B, X(rcl3) },
665 { IEEE80211_MODE_11A, X(rcl1) },
666 { IEEE80211_MODE_11A, X(rcl2) },
667 { IEEE80211_MODE_11B, X(rcl8) },
668 { IEEE80211_MODE_11B, X(rcl9) },
669 { IEEE80211_MODE_11A, X(rcl4) },
670 #ifdef ATH_TURBO_SCAN
671 { IEEE80211_MODE_STURBO_A, X(rcl5) },
672 { IEEE80211_MODE_STURBO_A, X(rcl6) },
673 { IEEE80211_MODE_TURBO_A, X(rcl6x) },
674 { IEEE80211_MODE_TURBO_A, X(rcl13) },
675 #endif /* ATH_TURBO_SCAN */
676 { IEEE80211_MODE_11A, X(rcl7) },
677 { IEEE80211_MODE_11B, X(rcl10) },
678 { IEEE80211_MODE_11A, X(rcl11) },
679 #ifdef ATH_TURBO_SCAN
680 { IEEE80211_MODE_TURBO_G, X(rcl12) },
681 #endif /* ATH_TURBO_SCAN */
682 { .list = NULL }
683 };
684
685 /*
686 * Start a station-mode scan by populating the channel list.
687 */
688 static int
689 sta_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
690 {
691 struct sta_table *st = ss->ss_priv;
692
693 makescanlist(ss, vap, staScanTable);
694
695 if (ss->ss_mindwell == 0)
696 ss->ss_mindwell = msecs_to_ticks(20); /* 20ms */
697 if (ss->ss_maxdwell == 0)
698 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
699
700 st->st_scangen++;
701 st->st_newscan = 1;
702
703 return 0;
704 }
705
706 /*
707 * Restart a scan, typically a bg scan but can
708 * also be a fg scan that came up empty.
709 */
710 static int
711 sta_restart(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
712 {
713 struct sta_table *st = ss->ss_priv;
714
715 st->st_newscan = 1;
716 return 0;
717 }
718
719 /*
720 * Cancel an ongoing scan.
721 */
722 static int
723 sta_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
724 {
725 return 0;
726 }
727
728 /* unalligned little endian access */
729 #define LE_READ_2(p) \
730 ((uint16_t) \
731 ((((const uint8_t *)(p))[0] ) | \
732 (((const uint8_t *)(p))[1] << 8)))
733
734 /*
735 * Demote any supplied 11g channel to 11b. There should
736 * always be an 11b channel but we check anyway...
737 */
738 static struct ieee80211_channel *
739 demote11b(struct ieee80211vap *vap, struct ieee80211_channel *chan)
740 {
741 struct ieee80211_channel *c;
742
743 if (IEEE80211_IS_CHAN_ANYG(chan) &&
744 vap->iv_des_mode == IEEE80211_MODE_AUTO) {
745 c = ieee80211_find_channel(vap->iv_ic, chan->ic_freq,
746 (chan->ic_flags &~ (IEEE80211_CHAN_PUREG | IEEE80211_CHAN_G)) |
747 IEEE80211_CHAN_B);
748 if (c != NULL)
749 chan = c;
750 }
751 return chan;
752 }
753
754 static int
755 maxrate(const struct ieee80211_scan_entry *se)
756 {
757 const struct ieee80211_ie_htcap *htcap =
758 (const struct ieee80211_ie_htcap *) se->se_ies.htcap_ie;
759 int rmax, r, i;
760 uint16_t caps;
761
762 rmax = 0;
763 if (htcap != NULL) {
764 /*
765 * HT station; inspect supported MCS and then adjust
766 * rate by channel width. Could also include short GI
767 * in this if we want to be extra accurate.
768 */
769 /* XXX assumes MCS15 is max */
770 for (i = 15; i >= 0 && isclr(htcap->hc_mcsset, i); i--)
771 ;
772 if (i >= 0) {
773 caps = LE_READ_2(&htcap->hc_cap);
774 /* XXX short/long GI */
775 if (caps & IEEE80211_HTCAP_CHWIDTH40)
776 rmax = ieee80211_htrates[i].ht40_rate_400ns;
777 else
778 rmax = ieee80211_htrates[i].ht40_rate_800ns;
779 }
780 }
781 for (i = 0; i < se->se_rates[1]; i++) {
782 r = se->se_rates[2+i] & IEEE80211_RATE_VAL;
783 if (r > rmax)
784 rmax = r;
785 }
786 for (i = 0; i < se->se_xrates[1]; i++) {
787 r = se->se_xrates[2+i] & IEEE80211_RATE_VAL;
788 if (r > rmax)
789 rmax = r;
790 }
791 return rmax;
792 }
793
794 /*
795 * Compare the capabilities of two entries and decide which is
796 * more desirable (return >0 if a is considered better). Note
797 * that we assume compatibility/usability has already been checked
798 * so we don't need to (e.g. validate whether privacy is supported).
799 * Used to select the best scan candidate for association in a BSS.
800 */
801 static int
802 sta_compare(const struct sta_entry *a, const struct sta_entry *b)
803 {
804 #define PREFER(_a,_b,_what) do { \
805 if (((_a) ^ (_b)) & (_what)) \
806 return ((_a) & (_what)) ? 1 : -1; \
807 } while (0)
808 int maxa, maxb;
809 int8_t rssia, rssib;
810 int weight;
811
812 /* privacy support */
813 PREFER(a->base.se_capinfo, b->base.se_capinfo,
814 IEEE80211_CAPINFO_PRIVACY);
815
816 /* compare count of previous failures */
817 weight = b->se_fails - a->se_fails;
818 if (abs(weight) > 1)
819 return weight;
820
821 /*
822 * Compare rssi. If the two are considered equivalent
823 * then fallback to other criteria. We threshold the
824 * comparisons to avoid selecting an ap purely by rssi
825 * when both values may be good but one ap is otherwise
826 * more desirable (e.g. an 11b-only ap with stronger
827 * signal than an 11g ap).
828 */
829 rssia = MIN(a->base.se_rssi, STA_RSSI_MAX);
830 rssib = MIN(b->base.se_rssi, STA_RSSI_MAX);
831 if (abs(rssib - rssia) < 5) {
832 /* best/max rate preferred if signal level close enough XXX */
833 maxa = maxrate(&a->base);
834 maxb = maxrate(&b->base);
835 if (maxa != maxb)
836 return maxa - maxb;
837 /* XXX use freq for channel preference */
838 /* for now just prefer 5Ghz band to all other bands */
839 PREFER(IEEE80211_IS_CHAN_5GHZ(a->base.se_chan),
840 IEEE80211_IS_CHAN_5GHZ(b->base.se_chan), 1);
841 }
842 /* all things being equal, use signal level */
843 return a->base.se_rssi - b->base.se_rssi;
844 #undef PREFER
845 }
846
847 /*
848 * Check rate set suitability and return the best supported rate.
849 * XXX inspect MCS for HT
850 */
851 static int
852 check_rate(struct ieee80211vap *vap, const struct ieee80211_channel *chan,
853 const struct ieee80211_scan_entry *se)
854 {
855 #define RV(v) ((v) & IEEE80211_RATE_VAL)
856 const struct ieee80211_rateset *srs;
857 int i, j, nrs, r, okrate, badrate, fixedrate, ucastrate;
858 const uint8_t *rs;
859
860 okrate = badrate = 0;
861
862 srs = ieee80211_get_suprates(vap->iv_ic, chan);
863 nrs = se->se_rates[1];
864 rs = se->se_rates+2;
865 /* XXX MCS */
866 ucastrate = vap->iv_txparms[ieee80211_chan2mode(chan)].ucastrate;
867 fixedrate = IEEE80211_FIXED_RATE_NONE;
868 again:
869 for (i = 0; i < nrs; i++) {
870 r = RV(rs[i]);
871 badrate = r;
872 /*
873 * Check any fixed rate is included.
874 */
875 if (r == ucastrate)
876 fixedrate = r;
877 /*
878 * Check against our supported rates.
879 */
880 for (j = 0; j < srs->rs_nrates; j++)
881 if (r == RV(srs->rs_rates[j])) {
882 if (r > okrate) /* NB: track max */
883 okrate = r;
884 break;
885 }
886
887 if (j == srs->rs_nrates && (rs[i] & IEEE80211_RATE_BASIC)) {
888 /*
889 * Don't try joining a BSS, if we don't support
890 * one of its basic rates.
891 */
892 okrate = 0;
893 goto back;
894 }
895 }
896 if (rs == se->se_rates+2) {
897 /* scan xrates too; sort of an algol68-style for loop */
898 nrs = se->se_xrates[1];
899 rs = se->se_xrates+2;
900 goto again;
901 }
902
903 back:
904 if (okrate == 0 || ucastrate != fixedrate)
905 return badrate | IEEE80211_RATE_BASIC;
906 else
907 return RV(okrate);
908 #undef RV
909 }
910
911 static __inline int
912 match_id(const uint8_t *ie, const uint8_t *val, int len)
913 {
914 return (ie[1] == len && memcmp(ie+2, val, len) == 0);
915 }
916
917 static int
918 match_ssid(const uint8_t *ie,
919 int nssid, const struct ieee80211_scan_ssid ssids[])
920 {
921 int i;
922
923 for (i = 0; i < nssid; i++) {
924 if (match_id(ie, ssids[i].ssid, ssids[i].len))
925 return 1;
926 }
927 return 0;
928 }
929
930 #ifdef IEEE80211_SUPPORT_TDMA
931 static int
932 tdma_isfull(const struct ieee80211_tdma_param *tdma)
933 {
934 int slot, slotcnt;
935
936 slotcnt = tdma->tdma_slotcnt;
937 for (slot = slotcnt-1; slot >= 0; slot--)
938 if (isclr(tdma->tdma_inuse, slot))
939 return 0;
940 return 1;
941 }
942 #endif /* IEEE80211_SUPPORT_TDMA */
943
944 /*
945 * Test a scan candidate for suitability/compatibility.
946 */
947 static int
948 match_bss(struct ieee80211vap *vap,
949 const struct ieee80211_scan_state *ss, struct sta_entry *se0,
950 int debug)
951 {
952 struct ieee80211com *ic = vap->iv_ic;
953 struct ieee80211_scan_entry *se = &se0->base;
954 uint8_t rate;
955 int fail;
956
957 fail = 0;
958 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, se->se_chan)))
959 fail |= MATCH_CHANNEL;
960 /*
961 * NB: normally the desired mode is used to construct
962 * the channel list, but it's possible for the scan
963 * cache to include entries for stations outside this
964 * list so we check the desired mode here to weed them
965 * out.
966 */
967 if (vap->iv_des_mode != IEEE80211_MODE_AUTO &&
968 (se->se_chan->ic_flags & IEEE80211_CHAN_ALLTURBO) !=
969 chanflags[vap->iv_des_mode])
970 fail |= MATCH_CHANNEL;
971 if (vap->iv_opmode == IEEE80211_M_IBSS) {
972 if ((se->se_capinfo & IEEE80211_CAPINFO_IBSS) == 0)
973 fail |= MATCH_CAPINFO;
974 #ifdef IEEE80211_SUPPORT_TDMA
975 } else if (vap->iv_opmode == IEEE80211_M_AHDEMO) {
976 /*
977 * Adhoc demo network setup shouldn't really be scanning
978 * but just in case skip stations operating in IBSS or
979 * BSS mode.
980 */
981 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS))
982 fail |= MATCH_CAPINFO;
983 /*
984 * TDMA operation cannot coexist with a normal 802.11 network;
985 * skip if IBSS or ESS capabilities are marked and require
986 * the beacon have a TDMA ie present.
987 */
988 if (vap->iv_caps & IEEE80211_C_TDMA) {
989 const struct ieee80211_tdma_param *tdma =
990 (const struct ieee80211_tdma_param *)se->se_ies.tdma_ie;
991 const struct ieee80211_tdma_state *ts = vap->iv_tdma;
992
993 if (tdma == NULL)
994 fail |= MATCH_TDMA_NOIE;
995 else if (tdma->tdma_version != ts->tdma_version)
996 fail |= MATCH_TDMA_VERSION;
997 else if (tdma->tdma_slot != 0)
998 fail |= MATCH_TDMA_NOTMASTER;
999 else if (tdma_isfull(tdma))
1000 fail |= MATCH_TDMA_NOSLOT;
1001 #if 0
1002 else if (ieee80211_local_address(se->se_macaddr))
1003 fail |= MATCH_TDMA_LOCAL;
1004 #endif
1005 }
1006 #endif /* IEEE80211_SUPPORT_TDMA */
1007 #ifdef IEEE80211_SUPPORT_MESH
1008 } else if (vap->iv_opmode == IEEE80211_M_MBSS) {
1009 const struct ieee80211_mesh_state *ms = vap->iv_mesh;
1010 /*
1011 * Mesh nodes have IBSS & ESS bits in capinfo turned off
1012 * and two special ie's that must be present.
1013 */
1014 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS))
1015 fail |= MATCH_CAPINFO;
1016 else if (se->se_meshid == NULL)
1017 fail |= MATCH_MESH_NOID;
1018 else if (ms->ms_idlen != 0 &&
1019 match_id(se->se_meshid, ms->ms_id, ms->ms_idlen))
1020 fail |= MATCH_MESHID;
1021 #endif
1022 } else {
1023 if ((se->se_capinfo & IEEE80211_CAPINFO_ESS) == 0)
1024 fail |= MATCH_CAPINFO;
1025 /*
1026 * If 11d is enabled and we're attempting to join a bss
1027 * that advertises it's country code then compare our
1028 * current settings to what we fetched from the country ie.
1029 * If our country code is unspecified or different then do
1030 * not attempt to join the bss. We should have already
1031 * dispatched an event to user space that identifies the
1032 * new country code so our regdomain config should match.
1033 */
1034 if ((IEEE80211_IS_CHAN_11D(se->se_chan) ||
1035 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) &&
1036 se->se_cc[0] != 0 &&
1037 (ic->ic_regdomain.country == CTRY_DEFAULT ||
1038 !isocmp(se->se_cc, ic->ic_regdomain.isocc)))
1039 fail |= MATCH_CC;
1040 }
1041 if (vap->iv_flags & IEEE80211_F_PRIVACY) {
1042 if ((se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0)
1043 fail |= MATCH_PRIVACY;
1044 } else {
1045 /* XXX does this mean privacy is supported or required? */
1046 if (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY)
1047 fail |= MATCH_PRIVACY;
1048 }
1049 se0->se_flags &= ~STA_DEMOTE11B;
1050 rate = check_rate(vap, se->se_chan, se);
1051 if (rate & IEEE80211_RATE_BASIC) {
1052 fail |= MATCH_RATE;
1053 /*
1054 * An 11b-only ap will give a rate mismatch if there is an
1055 * OFDM fixed tx rate for 11g. Try downgrading the channel
1056 * in the scan list to 11b and retry the rate check.
1057 */
1058 if (IEEE80211_IS_CHAN_ANYG(se->se_chan)) {
1059 rate = check_rate(vap, demote11b(vap, se->se_chan), se);
1060 if ((rate & IEEE80211_RATE_BASIC) == 0) {
1061 fail &= ~MATCH_RATE;
1062 se0->se_flags |= STA_DEMOTE11B;
1063 }
1064 }
1065 } else if (rate < 2*24) {
1066 /*
1067 * This is an 11b-only ap. Check the desired mode in
1068 * case that needs to be honored (mode 11g filters out
1069 * 11b-only ap's). Otherwise force any 11g channel used
1070 * in scanning to be demoted.
1071 *
1072 * NB: we cheat a bit here by looking at the max rate;
1073 * we could/should check the rates.
1074 */
1075 if (!(vap->iv_des_mode == IEEE80211_MODE_AUTO ||
1076 vap->iv_des_mode == IEEE80211_MODE_11B))
1077 fail |= MATCH_RATE;
1078 else
1079 se0->se_flags |= STA_DEMOTE11B;
1080 }
1081 if (ss->ss_nssid != 0 &&
1082 !match_ssid(se->se_ssid, ss->ss_nssid, ss->ss_ssid))
1083 fail |= MATCH_SSID;
1084 if ((vap->iv_flags & IEEE80211_F_DESBSSID) &&
1085 !IEEE80211_ADDR_EQ(vap->iv_des_bssid, se->se_bssid))
1086 fail |= MATCH_BSSID;
1087 if (se0->se_fails >= STA_FAILS_MAX)
1088 fail |= MATCH_FAILS;
1089 if (se0->se_notseen >= STA_PURGE_SCANS)
1090 fail |= MATCH_NOTSEEN;
1091 if (se->se_rssi < STA_RSSI_MIN)
1092 fail |= MATCH_RSSI;
1093 #ifdef IEEE80211_DEBUG
1094 if (ieee80211_msg(vap, debug)) {
1095 printf(" %c %s",
1096 fail & MATCH_FAILS ? '=' :
1097 fail & MATCH_NOTSEEN ? '^' :
1098 fail & MATCH_CC ? '$' :
1099 #ifdef IEEE80211_SUPPORT_TDMA
1100 fail & MATCH_TDMA_NOIE ? '&' :
1101 fail & MATCH_TDMA_VERSION ? 'v' :
1102 fail & MATCH_TDMA_NOTMASTER ? 's' :
1103 fail & MATCH_TDMA_NOSLOT ? 'f' :
1104 fail & MATCH_TDMA_LOCAL ? 'l' :
1105 #endif
1106 fail & MATCH_MESH_NOID ? 'm' :
1107 fail ? '-' : '+', ether_sprintf(se->se_macaddr));
1108 printf(" %s%c", ether_sprintf(se->se_bssid),
1109 fail & MATCH_BSSID ? '!' : ' ');
1110 printf(" %3d%c", ieee80211_chan2ieee(ic, se->se_chan),
1111 fail & MATCH_CHANNEL ? '!' : ' ');
1112 printf(" %+4d%c", se->se_rssi, fail & MATCH_RSSI ? '!' : ' ');
1113 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2,
1114 fail & MATCH_RATE ? '!' : ' ');
1115 printf(" %4s%c",
1116 (se->se_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" :
1117 (se->se_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : "",
1118 fail & MATCH_CAPINFO ? '!' : ' ');
1119 printf(" %3s%c ",
1120 (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) ?
1121 "wep" : "no",
1122 fail & MATCH_PRIVACY ? '!' : ' ');
1123 ieee80211_print_essid(se->se_ssid+2, se->se_ssid[1]);
1124 printf("%s\n", fail & (MATCH_SSID | MATCH_MESHID) ? "!" : "");
1125 }
1126 #endif
1127 return fail;
1128 }
1129
1130 static void
1131 sta_update_notseen(struct sta_table *st)
1132 {
1133 struct sta_entry *se;
1134
1135 mtx_lock(&st->st_lock);
1136 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1137 /*
1138 * If seen the reset and don't bump the count;
1139 * otherwise bump the ``not seen'' count. Note
1140 * that this insures that stations for which we
1141 * see frames while not scanning but not during
1142 * this scan will not be penalized.
1143 */
1144 if (se->se_seen)
1145 se->se_seen = 0;
1146 else
1147 se->se_notseen++;
1148 }
1149 mtx_unlock(&st->st_lock);
1150 }
1151
1152 static void
1153 sta_dec_fails(struct sta_table *st)
1154 {
1155 struct sta_entry *se;
1156
1157 mtx_lock(&st->st_lock);
1158 TAILQ_FOREACH(se, &st->st_entry, se_list)
1159 if (se->se_fails)
1160 se->se_fails--;
1161 mtx_unlock(&st->st_lock);
1162 }
1163
1164 static struct sta_entry *
1165 select_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, int debug)
1166 {
1167 struct sta_table *st = ss->ss_priv;
1168 struct sta_entry *se, *selbs = NULL;
1169
1170 IEEE80211_DPRINTF(vap, debug, " %s\n",
1171 "macaddr bssid chan rssi rate flag wep essid");
1172 mtx_lock(&st->st_lock);
1173 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1174 ieee80211_ies_expand(&se->base.se_ies);
1175 if (match_bss(vap, ss, se, debug) == 0) {
1176 if (selbs == NULL)
1177 selbs = se;
1178 else if (sta_compare(se, selbs) > 0)
1179 selbs = se;
1180 }
1181 }
1182 mtx_unlock(&st->st_lock);
1183
1184 return selbs;
1185 }
1186
1187 /*
1188 * Pick an ap or ibss network to join or find a channel
1189 * to use to start an ibss network.
1190 */
1191 static int
1192 sta_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1193 {
1194 struct sta_table *st = ss->ss_priv;
1195 struct sta_entry *selbs;
1196 struct ieee80211_channel *chan;
1197
1198 KASSERT(vap->iv_opmode == IEEE80211_M_STA,
1199 ("wrong mode %u", vap->iv_opmode));
1200
1201 if (st->st_newscan) {
1202 sta_update_notseen(st);
1203 st->st_newscan = 0;
1204 }
1205 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1206 /*
1207 * Manual/background scan, don't select+join the
1208 * bss, just return. The scanning framework will
1209 * handle notification that this has completed.
1210 */
1211 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1212 return 1;
1213 }
1214 /*
1215 * Automatic sequencing; look for a candidate and
1216 * if found join the network.
1217 */
1218 /* NB: unlocked read should be ok */
1219 if (TAILQ_FIRST(&st->st_entry) == NULL) {
1220 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1221 "%s: no scan candidate\n", __func__);
1222 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1223 return 0;
1224 notfound:
1225 /*
1226 * If nothing suitable was found decrement
1227 * the failure counts so entries will be
1228 * reconsidered the next time around. We
1229 * really want to do this only for sta's
1230 * where we've previously had some success.
1231 */
1232 sta_dec_fails(st);
1233 st->st_newscan = 1;
1234 return 0; /* restart scan */
1235 }
1236 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1237 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1238 return (selbs != NULL);
1239 if (selbs == NULL)
1240 goto notfound;
1241 chan = selbs->base.se_chan;
1242 if (selbs->se_flags & STA_DEMOTE11B)
1243 chan = demote11b(vap, chan);
1244 if (!ieee80211_sta_join(vap, chan, &selbs->base))
1245 goto notfound;
1246 return 1; /* terminate scan */
1247 }
1248
1249 /*
1250 * Lookup an entry in the scan cache. We assume we're
1251 * called from the bottom half or such that we don't need
1252 * to block the bottom half so that it's safe to return
1253 * a reference to an entry w/o holding the lock on the table.
1254 */
1255 static struct sta_entry *
1256 sta_lookup(struct sta_table *st, const uint8_t macaddr[IEEE80211_ADDR_LEN])
1257 {
1258 struct sta_entry *se;
1259 int hash = STA_HASH(macaddr);
1260
1261 mtx_lock(&st->st_lock);
1262 LIST_FOREACH(se, &st->st_hash[hash], se_hash)
1263 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr))
1264 break;
1265 mtx_unlock(&st->st_lock);
1266
1267 return se; /* NB: unlocked */
1268 }
1269
1270 static void
1271 sta_roam_check(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1272 {
1273 struct ieee80211com *ic = vap->iv_ic;
1274 struct ieee80211_node *ni = vap->iv_bss;
1275 struct sta_table *st = ss->ss_priv;
1276 enum ieee80211_phymode mode;
1277 struct sta_entry *se, *selbs;
1278 uint8_t roamRate, curRate, ucastRate;
1279 int8_t roamRssi, curRssi;
1280
1281 se = sta_lookup(st, ni->ni_macaddr);
1282 if (se == NULL) {
1283 /* XXX something is wrong */
1284 return;
1285 }
1286
1287 mode = ieee80211_chan2mode(ic->ic_bsschan);
1288 roamRate = vap->iv_roamparms[mode].rate;
1289 roamRssi = vap->iv_roamparms[mode].rssi;
1290 ucastRate = vap->iv_txparms[mode].ucastrate;
1291 /* NB: the most up to date rssi is in the node, not the scan cache */
1292 curRssi = ic->ic_node_getrssi(ni);
1293 if (ucastRate == IEEE80211_FIXED_RATE_NONE) {
1294 curRate = ni->ni_txrate;
1295 roamRate &= IEEE80211_RATE_VAL;
1296 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM,
1297 "%s: currssi %d currate %u roamrssi %d roamrate %u\n",
1298 __func__, curRssi, curRate, roamRssi, roamRate);
1299 } else {
1300 curRate = roamRate; /* NB: insure compare below fails */
1301 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM,
1302 "%s: currssi %d roamrssi %d\n", __func__, curRssi, roamRssi);
1303 }
1304 /*
1305 * Check if a new ap should be used and switch.
1306 * XXX deauth current ap
1307 */
1308 if (curRate < roamRate || curRssi < roamRssi) {
1309 if (time_after(ticks, ic->ic_lastscan + vap->iv_scanvalid)) {
1310 /*
1311 * Scan cache contents are too old; force a scan now
1312 * if possible so we have current state to make a
1313 * decision with. We don't kick off a bg scan if
1314 * we're using dynamic turbo and boosted or if the
1315 * channel is busy.
1316 * XXX force immediate switch on scan complete
1317 */
1318 if (!IEEE80211_IS_CHAN_DTURBO(ic->ic_curchan) &&
1319 time_after(ticks, ic->ic_lastdata + vap->iv_bgscanidle))
1320 ieee80211_bg_scan(vap, 0);
1321 return;
1322 }
1323 se->base.se_rssi = curRssi;
1324 selbs = select_bss(ss, vap, IEEE80211_MSG_ROAM);
1325 if (selbs != NULL && selbs != se) {
1326 struct ieee80211_channel *chan;
1327
1328 IEEE80211_DPRINTF(vap,
1329 IEEE80211_MSG_ROAM | IEEE80211_MSG_DEBUG,
1330 "%s: ROAM: curRate %u, roamRate %u, "
1331 "curRssi %d, roamRssi %d\n", __func__,
1332 curRate, roamRate, curRssi, roamRssi);
1333
1334 chan = selbs->base.se_chan;
1335 if (selbs->se_flags & STA_DEMOTE11B)
1336 chan = demote11b(vap, chan);
1337 (void) ieee80211_sta_join(vap, chan, &selbs->base);
1338 }
1339 }
1340 }
1341
1342 /*
1343 * Age entries in the scan cache.
1344 * XXX also do roaming since it's convenient
1345 */
1346 static void
1347 sta_age(struct ieee80211_scan_state *ss)
1348 {
1349 struct ieee80211vap *vap = ss->ss_vap;
1350
1351 adhoc_age(ss);
1352 /*
1353 * If rate control is enabled check periodically to see if
1354 * we should roam from our current connection to one that
1355 * might be better. This only applies when we're operating
1356 * in sta mode and automatic roaming is set.
1357 * XXX defer if busy
1358 * XXX repeater station
1359 * XXX do when !bgscan?
1360 */
1361 KASSERT(vap->iv_opmode == IEEE80211_M_STA,
1362 ("wrong mode %u", vap->iv_opmode));
1363 if (vap->iv_roaming == IEEE80211_ROAMING_AUTO &&
1364 (vap->iv_ic->ic_flags & IEEE80211_F_BGSCAN) &&
1365 vap->iv_state >= IEEE80211_S_RUN)
1366 /* XXX vap is implicit */
1367 sta_roam_check(ss, vap);
1368 }
1369
1370 /*
1371 * Iterate over the entries in the scan cache, invoking
1372 * the callback function on each one.
1373 */
1374 static void
1375 sta_iterate(struct ieee80211_scan_state *ss,
1376 ieee80211_scan_iter_func *f, void *arg)
1377 {
1378 struct sta_table *st = ss->ss_priv;
1379 struct sta_entry *se;
1380 u_int gen;
1381
1382 mtx_lock(&st->st_scanlock);
1383 gen = st->st_scaniter++;
1384 restart:
1385 mtx_lock(&st->st_lock);
1386 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1387 if (se->se_scangen != gen) {
1388 se->se_scangen = gen;
1389 /* update public state */
1390 se->base.se_age = ticks - se->se_lastupdate;
1391 mtx_unlock(&st->st_lock);
1392 (*f)(arg, &se->base);
1393 goto restart;
1394 }
1395 }
1396 mtx_unlock(&st->st_lock);
1397
1398 mtx_unlock(&st->st_scanlock);
1399 }
1400
1401 static void
1402 sta_assoc_fail(struct ieee80211_scan_state *ss,
1403 const uint8_t macaddr[IEEE80211_ADDR_LEN], int reason)
1404 {
1405 struct sta_table *st = ss->ss_priv;
1406 struct sta_entry *se;
1407
1408 se = sta_lookup(st, macaddr);
1409 if (se != NULL) {
1410 se->se_fails++;
1411 se->se_lastfail = ticks;
1412 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN,
1413 macaddr, "%s: reason %u fails %u",
1414 __func__, reason, se->se_fails);
1415 }
1416 }
1417
1418 static void
1419 sta_assoc_success(struct ieee80211_scan_state *ss,
1420 const uint8_t macaddr[IEEE80211_ADDR_LEN])
1421 {
1422 struct sta_table *st = ss->ss_priv;
1423 struct sta_entry *se;
1424
1425 se = sta_lookup(st, macaddr);
1426 if (se != NULL) {
1427 #if 0
1428 se->se_fails = 0;
1429 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN,
1430 macaddr, "%s: fails %u",
1431 __func__, se->se_fails);
1432 #endif
1433 se->se_lastassoc = ticks;
1434 }
1435 }
1436
1437 static const struct ieee80211_scanner sta_default = {
1438 .scan_name = "default",
1439 .scan_attach = sta_attach,
1440 .scan_detach = sta_detach,
1441 .scan_start = sta_start,
1442 .scan_restart = sta_restart,
1443 .scan_cancel = sta_cancel,
1444 .scan_end = sta_pick_bss,
1445 .scan_flush = sta_flush,
1446 .scan_add = sta_add,
1447 .scan_age = sta_age,
1448 .scan_iterate = sta_iterate,
1449 .scan_assoc_fail = sta_assoc_fail,
1450 .scan_assoc_success = sta_assoc_success,
1451 };
1452 IEEE80211_SCANNER_ALG(sta, IEEE80211_M_STA, sta_default);
1453
1454 /*
1455 * Adhoc mode-specific support.
1456 */
1457
1458 static const uint16_t adhocWorld[] = /* 36, 40, 44, 48 */
1459 { 5180, 5200, 5220, 5240 };
1460 static const uint16_t adhocFcc3[] = /* 36, 40, 44, 48 145, 149, 153, 157, 161, 165 */
1461 { 5180, 5200, 5220, 5240, 5725, 5745, 5765, 5785, 5805, 5825 };
1462 static const uint16_t adhocMkk[] = /* 34, 38, 42, 46 */
1463 { 5170, 5190, 5210, 5230 };
1464 static const uint16_t adhoc11b[] = /* 10, 11 */
1465 { 2457, 2462 };
1466
1467 static const struct scanlist adhocScanTable[] = {
1468 { IEEE80211_MODE_11B, X(adhoc11b) },
1469 { IEEE80211_MODE_11A, X(adhocWorld) },
1470 { IEEE80211_MODE_11A, X(adhocFcc3) },
1471 { IEEE80211_MODE_11B, X(adhocMkk) },
1472 { .list = NULL }
1473 };
1474 #undef X
1475
1476 /*
1477 * Start an adhoc-mode scan by populating the channel list.
1478 */
1479 static int
1480 adhoc_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1481 {
1482 struct sta_table *st = ss->ss_priv;
1483
1484 makescanlist(ss, vap, adhocScanTable);
1485
1486 if (ss->ss_mindwell == 0)
1487 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */
1488 if (ss->ss_maxdwell == 0)
1489 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
1490
1491 st->st_scangen++;
1492 st->st_newscan = 1;
1493
1494 return 0;
1495 }
1496
1497 /*
1498 * Select a channel to start an adhoc network on.
1499 * The channel list was populated with appropriate
1500 * channels so select one that looks least occupied.
1501 */
1502 static struct ieee80211_channel *
1503 adhoc_pick_channel(struct ieee80211_scan_state *ss, int flags)
1504 {
1505 struct sta_table *st = ss->ss_priv;
1506 struct sta_entry *se;
1507 struct ieee80211_channel *c, *bestchan;
1508 int i, bestrssi, maxrssi;
1509
1510 bestchan = NULL;
1511 bestrssi = -1;
1512
1513 mtx_lock(&st->st_lock);
1514 for (i = 0; i < ss->ss_last; i++) {
1515 c = ss->ss_chans[i];
1516 /* never consider a channel with radar */
1517 if (IEEE80211_IS_CHAN_RADAR(c))
1518 continue;
1519 /* skip channels disallowed by regulatory settings */
1520 if (IEEE80211_IS_CHAN_NOADHOC(c))
1521 continue;
1522 /* check channel attributes for band compatibility */
1523 if (flags != 0 && (c->ic_flags & flags) != flags)
1524 continue;
1525 maxrssi = 0;
1526 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1527 if (se->base.se_chan != c)
1528 continue;
1529 if (se->base.se_rssi > maxrssi)
1530 maxrssi = se->base.se_rssi;
1531 }
1532 if (bestchan == NULL || maxrssi < bestrssi)
1533 bestchan = c;
1534 }
1535 mtx_unlock(&st->st_lock);
1536
1537 return bestchan;
1538 }
1539
1540 /*
1541 * Pick an ibss network to join or find a channel
1542 * to use to start an ibss network.
1543 */
1544 static int
1545 adhoc_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1546 {
1547 struct sta_table *st = ss->ss_priv;
1548 struct sta_entry *selbs;
1549 struct ieee80211_channel *chan;
1550
1551 KASSERT(vap->iv_opmode == IEEE80211_M_IBSS ||
1552 vap->iv_opmode == IEEE80211_M_AHDEMO ||
1553 vap->iv_opmode == IEEE80211_M_MBSS,
1554 ("wrong opmode %u", vap->iv_opmode));
1555
1556 if (st->st_newscan) {
1557 sta_update_notseen(st);
1558 st->st_newscan = 0;
1559 }
1560 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1561 /*
1562 * Manual/background scan, don't select+join the
1563 * bss, just return. The scanning framework will
1564 * handle notification that this has completed.
1565 */
1566 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1567 return 1;
1568 }
1569 /*
1570 * Automatic sequencing; look for a candidate and
1571 * if found join the network.
1572 */
1573 /* NB: unlocked read should be ok */
1574 if (TAILQ_FIRST(&st->st_entry) == NULL) {
1575 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1576 "%s: no scan candidate\n", __func__);
1577 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1578 return 0;
1579 notfound:
1580 /* NB: never auto-start a tdma network for slot !0 */
1581 #ifdef IEEE80211_SUPPORT_TDMA
1582 if (vap->iv_des_nssid &&
1583 ((vap->iv_caps & IEEE80211_C_TDMA) == 0 ||
1584 ieee80211_tdma_getslot(vap) == 0)) {
1585 #else
1586 if (vap->iv_des_nssid) {
1587 #endif
1588 /*
1589 * No existing adhoc network to join and we have
1590 * an ssid; start one up. If no channel was
1591 * specified, try to select a channel.
1592 */
1593 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC ||
1594 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
1595 struct ieee80211com *ic = vap->iv_ic;
1596
1597 chan = adhoc_pick_channel(ss, 0);
1598 if (chan != NULL)
1599 chan = ieee80211_ht_adjust_channel(ic,
1600 chan, vap->iv_flags_ht);
1601 } else
1602 chan = vap->iv_des_chan;
1603 if (chan != NULL) {
1604 ieee80211_create_ibss(vap, chan);
1605 return 1;
1606 }
1607 }
1608 /*
1609 * If nothing suitable was found decrement
1610 * the failure counts so entries will be
1611 * reconsidered the next time around. We
1612 * really want to do this only for sta's
1613 * where we've previously had some success.
1614 */
1615 sta_dec_fails(st);
1616 st->st_newscan = 1;
1617 return 0; /* restart scan */
1618 }
1619 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1620 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1621 return (selbs != NULL);
1622 if (selbs == NULL)
1623 goto notfound;
1624 chan = selbs->base.se_chan;
1625 if (selbs->se_flags & STA_DEMOTE11B)
1626 chan = demote11b(vap, chan);
1627 if (!ieee80211_sta_join(vap, chan, &selbs->base))
1628 goto notfound;
1629 return 1; /* terminate scan */
1630 }
1631
1632 /*
1633 * Age entries in the scan cache.
1634 */
1635 static void
1636 adhoc_age(struct ieee80211_scan_state *ss)
1637 {
1638 struct sta_table *st = ss->ss_priv;
1639 struct sta_entry *se, *next;
1640
1641 mtx_lock(&st->st_lock);
1642 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) {
1643 if (se->se_notseen > STA_PURGE_SCANS) {
1644 TAILQ_REMOVE(&st->st_entry, se, se_list);
1645 LIST_REMOVE(se, se_hash);
1646 ieee80211_ies_cleanup(&se->base.se_ies);
1647 free(se, M_80211_SCAN);
1648 }
1649 }
1650 mtx_unlock(&st->st_lock);
1651 }
1652
1653 static const struct ieee80211_scanner adhoc_default = {
1654 .scan_name = "default",
1655 .scan_attach = sta_attach,
1656 .scan_detach = sta_detach,
1657 .scan_start = adhoc_start,
1658 .scan_restart = sta_restart,
1659 .scan_cancel = sta_cancel,
1660 .scan_end = adhoc_pick_bss,
1661 .scan_flush = sta_flush,
1662 .scan_pickchan = adhoc_pick_channel,
1663 .scan_add = sta_add,
1664 .scan_age = adhoc_age,
1665 .scan_iterate = sta_iterate,
1666 .scan_assoc_fail = sta_assoc_fail,
1667 .scan_assoc_success = sta_assoc_success,
1668 };
1669 IEEE80211_SCANNER_ALG(ibss, IEEE80211_M_IBSS, adhoc_default);
1670 IEEE80211_SCANNER_ALG(ahdemo, IEEE80211_M_AHDEMO, adhoc_default);
1671
1672 static void
1673 ap_force_promisc(struct ieee80211com *ic)
1674 {
1675 struct ifnet *ifp = ic->ic_ifp;
1676
1677 IEEE80211_LOCK(ic);
1678 /* set interface into promiscuous mode */
1679 ifp->if_flags |= IFF_PROMISC;
1680 ieee80211_runtask(ic, &ic->ic_promisc_task);
1681 IEEE80211_UNLOCK(ic);
1682 }
1683
1684 static void
1685 ap_reset_promisc(struct ieee80211com *ic)
1686 {
1687 IEEE80211_LOCK(ic);
1688 ieee80211_syncifflag_locked(ic, IFF_PROMISC);
1689 IEEE80211_UNLOCK(ic);
1690 }
1691
1692 static int
1693 ap_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1694 {
1695 struct sta_table *st = ss->ss_priv;
1696
1697 makescanlist(ss, vap, staScanTable);
1698
1699 if (ss->ss_mindwell == 0)
1700 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */
1701 if (ss->ss_maxdwell == 0)
1702 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
1703
1704 st->st_scangen++;
1705 st->st_newscan = 1;
1706
1707 ap_force_promisc(vap->iv_ic);
1708 return 0;
1709 }
1710
1711 /*
1712 * Cancel an ongoing scan.
1713 */
1714 static int
1715 ap_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1716 {
1717 ap_reset_promisc(vap->iv_ic);
1718 return 0;
1719 }
1720
1721 /*
1722 * Pick a quiet channel to use for ap operation.
1723 */
1724 static struct ieee80211_channel *
1725 ap_pick_channel(struct ieee80211_scan_state *ss, int flags)
1726 {
1727 struct sta_table *st = ss->ss_priv;
1728 struct ieee80211_channel *bestchan = NULL;
1729 int i;
1730
1731 /* XXX select channel more intelligently, e.g. channel spread, power */
1732 /* NB: use scan list order to preserve channel preference */
1733 for (i = 0; i < ss->ss_last; i++) {
1734 struct ieee80211_channel *chan = ss->ss_chans[i];
1735 /*
1736 * If the channel is unoccupied the max rssi
1737 * should be zero; just take it. Otherwise
1738 * track the channel with the lowest rssi and
1739 * use that when all channels appear occupied.
1740 */
1741 if (IEEE80211_IS_CHAN_RADAR(chan))
1742 continue;
1743 if (IEEE80211_IS_CHAN_NOHOSTAP(chan))
1744 continue;
1745 /* check channel attributes for band compatibility */
1746 if (flags != 0 && (chan->ic_flags & flags) != flags)
1747 continue;
1748 KASSERT(sizeof(chan->ic_ieee) == 1, ("ic_chan size"));
1749 /* XXX channel have interference */
1750 if (st->st_maxrssi[chan->ic_ieee] == 0) {
1751 /* XXX use other considerations */
1752 return chan;
1753 }
1754 if (bestchan == NULL ||
1755 st->st_maxrssi[chan->ic_ieee] < st->st_maxrssi[bestchan->ic_ieee])
1756 bestchan = chan;
1757 }
1758 return bestchan;
1759 }
1760
1761 /*
1762 * Pick a quiet channel to use for ap operation.
1763 */
1764 static int
1765 ap_end(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1766 {
1767 struct ieee80211com *ic = vap->iv_ic;
1768 struct ieee80211_channel *bestchan;
1769
1770 KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP,
1771 ("wrong opmode %u", vap->iv_opmode));
1772 bestchan = ap_pick_channel(ss, 0);
1773 if (bestchan == NULL) {
1774 /* no suitable channel, should not happen */
1775 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1776 "%s: no suitable channel! (should not happen)\n", __func__);
1777 /* XXX print something? */
1778 return 0; /* restart scan */
1779 }
1780 /*
1781 * If this is a dynamic turbo channel, start with the unboosted one.
1782 */
1783 if (IEEE80211_IS_CHAN_TURBO(bestchan)) {
1784 bestchan = ieee80211_find_channel(ic, bestchan->ic_freq,
1785 bestchan->ic_flags & ~IEEE80211_CHAN_TURBO);
1786 if (bestchan == NULL) {
1787 /* should never happen ?? */
1788 return 0;
1789 }
1790 }
1791 ap_reset_promisc(ic);
1792 if (ss->ss_flags & (IEEE80211_SCAN_NOPICK | IEEE80211_SCAN_NOJOIN)) {
1793 /*
1794 * Manual/background scan, don't select+join the
1795 * bss, just return. The scanning framework will
1796 * handle notification that this has completed.
1797 */
1798 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1799 return 1;
1800 }
1801 ieee80211_create_ibss(vap,
1802 ieee80211_ht_adjust_channel(ic, bestchan, vap->iv_flags_ht));
1803 return 1;
1804 }
1805
1806 static const struct ieee80211_scanner ap_default = {
1807 .scan_name = "default",
1808 .scan_attach = sta_attach,
1809 .scan_detach = sta_detach,
1810 .scan_start = ap_start,
1811 .scan_restart = sta_restart,
1812 .scan_cancel = ap_cancel,
1813 .scan_end = ap_end,
1814 .scan_flush = sta_flush,
1815 .scan_pickchan = ap_pick_channel,
1816 .scan_add = sta_add,
1817 .scan_age = adhoc_age,
1818 .scan_iterate = sta_iterate,
1819 .scan_assoc_success = sta_assoc_success,
1820 .scan_assoc_fail = sta_assoc_fail,
1821 };
1822 IEEE80211_SCANNER_ALG(ap, IEEE80211_M_HOSTAP, ap_default);
1823
1824 #ifdef IEEE80211_SUPPORT_MESH
1825 /*
1826 * Pick an mbss network to join or find a channel
1827 * to use to start an mbss network.
1828 */
1829 static int
1830 mesh_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1831 {
1832 struct sta_table *st = ss->ss_priv;
1833 struct ieee80211_mesh_state *ms = vap->iv_mesh;
1834 struct sta_entry *selbs;
1835 struct ieee80211_channel *chan;
1836
1837 KASSERT(vap->iv_opmode == IEEE80211_M_MBSS,
1838 ("wrong opmode %u", vap->iv_opmode));
1839
1840 if (st->st_newscan) {
1841 sta_update_notseen(st);
1842 st->st_newscan = 0;
1843 }
1844 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1845 /*
1846 * Manual/background scan, don't select+join the
1847 * bss, just return. The scanning framework will
1848 * handle notification that this has completed.
1849 */
1850 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1851 return 1;
1852 }
1853 /*
1854 * Automatic sequencing; look for a candidate and
1855 * if found join the network.
1856 */
1857 /* NB: unlocked read should be ok */
1858 if (TAILQ_FIRST(&st->st_entry) == NULL) {
1859 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1860 "%s: no scan candidate\n", __func__);
1861 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1862 return 0;
1863 notfound:
1864 if (ms->ms_idlen != 0) {
1865 /*
1866 * No existing mbss network to join and we have
1867 * a meshid; start one up. If no channel was
1868 * specified, try to select a channel.
1869 */
1870 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC ||
1871 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
1872 struct ieee80211com *ic = vap->iv_ic;
1873
1874 chan = adhoc_pick_channel(ss, 0);
1875 if (chan != NULL)
1876 chan = ieee80211_ht_adjust_channel(ic,
1877 chan, vap->iv_flags_ht);
1878 } else
1879 chan = vap->iv_des_chan;
1880 if (chan != NULL) {
1881 ieee80211_create_ibss(vap, chan);
1882 return 1;
1883 }
1884 }
1885 /*
1886 * If nothing suitable was found decrement
1887 * the failure counts so entries will be
1888 * reconsidered the next time around. We
1889 * really want to do this only for sta's
1890 * where we've previously had some success.
1891 */
1892 sta_dec_fails(st);
1893 st->st_newscan = 1;
1894 return 0; /* restart scan */
1895 }
1896 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1897 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1898 return (selbs != NULL);
1899 if (selbs == NULL)
1900 goto notfound;
1901 chan = selbs->base.se_chan;
1902 if (selbs->se_flags & STA_DEMOTE11B)
1903 chan = demote11b(vap, chan);
1904 if (!ieee80211_sta_join(vap, chan, &selbs->base))
1905 goto notfound;
1906 return 1; /* terminate scan */
1907 }
1908
1909 static const struct ieee80211_scanner mesh_default = {
1910 .scan_name = "default",
1911 .scan_attach = sta_attach,
1912 .scan_detach = sta_detach,
1913 .scan_start = adhoc_start,
1914 .scan_restart = sta_restart,
1915 .scan_cancel = sta_cancel,
1916 .scan_end = mesh_pick_bss,
1917 .scan_flush = sta_flush,
1918 .scan_pickchan = adhoc_pick_channel,
1919 .scan_add = sta_add,
1920 .scan_age = adhoc_age,
1921 .scan_iterate = sta_iterate,
1922 .scan_assoc_fail = sta_assoc_fail,
1923 .scan_assoc_success = sta_assoc_success,
1924 };
1925 IEEE80211_SCANNER_ALG(mesh, IEEE80211_M_MBSS, mesh_default);
1926 #endif /* IEEE80211_SUPPORT_MESH */
Cache object: 517e1928642d9880cc9f3adf13173355
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