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/9.0/sys/net80211/ieee80211_scan_sta.c 224717 2011-08-08 16:29:07Z bschmidt $");
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 ieee80211_scan_table_lock_t 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 IEEE80211_SCAN_TABLE_LOCK_INIT(st, "scantable");
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 IEEE80211_SCAN_TABLE_LOCK_DESTROY(st);
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 IEEE80211_SCAN_TABLE_LOCK(st);
200 sta_flush_table(st);
201 IEEE80211_SCAN_TABLE_UNLOCK(st);
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 ieee80211_channel *c;
242 struct sta_entry *se;
243 struct ieee80211_scan_entry *ise;
244 int hash;
245
246 hash = STA_HASH(macaddr);
247
248 IEEE80211_SCAN_TABLE_LOCK(st);
249 LIST_FOREACH(se, &st->st_hash[hash], se_hash)
250 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr))
251 goto found;
252 se = (struct sta_entry *) malloc(sizeof(struct sta_entry),
253 M_80211_SCAN, M_NOWAIT | M_ZERO);
254 if (se == NULL) {
255 IEEE80211_SCAN_TABLE_UNLOCK(st);
256 return 0;
257 }
258 se->se_scangen = st->st_scaniter-1;
259 se->se_avgrssi = IEEE80211_RSSI_DUMMY_MARKER;
260 IEEE80211_ADDR_COPY(se->base.se_macaddr, macaddr);
261 TAILQ_INSERT_TAIL(&st->st_entry, se, se_list);
262 LIST_INSERT_HEAD(&st->st_hash[hash], se, se_hash);
263 found:
264 ise = &se->base;
265 /* XXX ap beaconing multiple ssid w/ same bssid */
266 if (sp->ssid[1] != 0 &&
267 (ISPROBE(subtype) || ise->se_ssid[1] == 0))
268 memcpy(ise->se_ssid, sp->ssid, 2+sp->ssid[1]);
269 KASSERT(sp->rates[1] <= IEEE80211_RATE_MAXSIZE,
270 ("rate set too large: %u", sp->rates[1]));
271 memcpy(ise->se_rates, sp->rates, 2+sp->rates[1]);
272 if (sp->xrates != NULL) {
273 /* XXX validate xrates[1] */
274 KASSERT(sp->xrates[1] <= IEEE80211_RATE_MAXSIZE,
275 ("xrate set too large: %u", sp->xrates[1]));
276 memcpy(ise->se_xrates, sp->xrates, 2+sp->xrates[1]);
277 } else
278 ise->se_xrates[1] = 0;
279 IEEE80211_ADDR_COPY(ise->se_bssid, wh->i_addr3);
280 if ((sp->status & IEEE80211_BPARSE_OFFCHAN) == 0) {
281 /*
282 * Record rssi data using extended precision LPF filter.
283 *
284 * NB: use only on-channel data to insure we get a good
285 * estimate of the signal we'll see when associated.
286 */
287 IEEE80211_RSSI_LPF(se->se_avgrssi, rssi);
288 ise->se_rssi = IEEE80211_RSSI_GET(se->se_avgrssi);
289 ise->se_noise = noise;
290 }
291 memcpy(ise->se_tstamp.data, sp->tstamp, sizeof(ise->se_tstamp));
292 ise->se_intval = sp->bintval;
293 ise->se_capinfo = sp->capinfo;
294 #ifdef IEEE80211_SUPPORT_MESH
295 if (sp->meshid != NULL && sp->meshid[1] != 0)
296 memcpy(ise->se_meshid, sp->meshid, 2+sp->meshid[1]);
297 #endif
298 /*
299 * Beware of overriding se_chan for frames seen
300 * off-channel; this can cause us to attempt an
301 * association on the wrong channel.
302 */
303 if (sp->status & IEEE80211_BPARSE_OFFCHAN) {
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 if (IEEE80211_IS_CHAN_HT(ise->se_chan) && sp->htcap == NULL) {
321 /* Demote legacy networks to a non-HT channel. */
322 c = ieee80211_find_channel(ic, ise->se_chan->ic_freq,
323 ise->se_chan->ic_flags & ~IEEE80211_CHAN_HT);
324 KASSERT(c != NULL,
325 ("no legacy channel %u", ise->se_chan->ic_ieee));
326 ise->se_chan = c;
327 }
328 ise->se_fhdwell = sp->fhdwell;
329 ise->se_fhindex = sp->fhindex;
330 ise->se_erp = sp->erp;
331 ise->se_timoff = sp->timoff;
332 if (sp->tim != NULL) {
333 const struct ieee80211_tim_ie *tim =
334 (const struct ieee80211_tim_ie *) sp->tim;
335 ise->se_dtimperiod = tim->tim_period;
336 }
337 if (sp->country != NULL) {
338 const struct ieee80211_country_ie *cie =
339 (const struct ieee80211_country_ie *) sp->country;
340 /*
341 * If 11d is enabled and we're attempting to join a bss
342 * that advertises it's country code then compare our
343 * current settings to what we fetched from the country ie.
344 * If our country code is unspecified or different then
345 * dispatch an event to user space that identifies the
346 * country code so our regdomain config can be changed.
347 */
348 /* XXX only for STA mode? */
349 if ((IEEE80211_IS_CHAN_11D(ise->se_chan) ||
350 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) &&
351 (ic->ic_regdomain.country == CTRY_DEFAULT ||
352 !isocmp(cie->cc, ic->ic_regdomain.isocc))) {
353 /* only issue one notify event per scan */
354 if (se->se_countrygen != st->st_scangen) {
355 ieee80211_notify_country(vap, ise->se_bssid,
356 cie->cc);
357 se->se_countrygen = st->st_scangen;
358 }
359 }
360 ise->se_cc[0] = cie->cc[0];
361 ise->se_cc[1] = cie->cc[1];
362 }
363 /* NB: no need to setup ie ptrs; they are not (currently) used */
364 (void) ieee80211_ies_init(&ise->se_ies, sp->ies, sp->ies_len);
365
366 /* clear failure count after STA_FAIL_AGE passes */
367 if (se->se_fails && (ticks - se->se_lastfail) > STA_FAILS_AGE*hz) {
368 se->se_fails = 0;
369 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, macaddr,
370 "%s: fails %u", __func__, se->se_fails);
371 }
372
373 se->se_lastupdate = ticks; /* update time */
374 se->se_seen = 1;
375 se->se_notseen = 0;
376
377 KASSERT(sizeof(sp->bchan) == 1, ("bchan size"));
378 if (rssi > st->st_maxrssi[sp->bchan])
379 st->st_maxrssi[sp->bchan] = rssi;
380
381 IEEE80211_SCAN_TABLE_UNLOCK(st);
382
383 /*
384 * If looking for a quick choice and nothing's
385 * been found check here.
386 */
387 if (PICK1ST(ss) && match_bss(vap, ss, se, IEEE80211_MSG_SCAN) == 0)
388 ss->ss_flags |= IEEE80211_SCAN_GOTPICK;
389
390 return 1;
391 #undef PICK1ST
392 #undef ISPROBE
393 }
394
395 /*
396 * Check if a channel is excluded by user request.
397 */
398 static int
399 isexcluded(struct ieee80211vap *vap, const struct ieee80211_channel *c)
400 {
401 return (isclr(vap->iv_ic->ic_chan_active, c->ic_ieee) ||
402 (vap->iv_des_chan != IEEE80211_CHAN_ANYC &&
403 c->ic_freq != vap->iv_des_chan->ic_freq));
404 }
405
406 static struct ieee80211_channel *
407 find11gchannel(struct ieee80211com *ic, int i, int freq)
408 {
409 struct ieee80211_channel *c;
410 int j;
411
412 /*
413 * The normal ordering in the channel list is b channel
414 * immediately followed by g so optimize the search for
415 * this. We'll still do a full search just in case.
416 */
417 for (j = i+1; j < ic->ic_nchans; j++) {
418 c = &ic->ic_channels[j];
419 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c))
420 return c;
421 }
422 for (j = 0; j < i; j++) {
423 c = &ic->ic_channels[j];
424 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c))
425 return c;
426 }
427 return NULL;
428 }
429
430 static const u_int chanflags[IEEE80211_MODE_MAX] = {
431 [IEEE80211_MODE_AUTO] = IEEE80211_CHAN_B,
432 [IEEE80211_MODE_11A] = IEEE80211_CHAN_A,
433 [IEEE80211_MODE_11B] = IEEE80211_CHAN_B,
434 [IEEE80211_MODE_11G] = IEEE80211_CHAN_G,
435 [IEEE80211_MODE_FH] = IEEE80211_CHAN_FHSS,
436 /* check base channel */
437 [IEEE80211_MODE_TURBO_A] = IEEE80211_CHAN_A,
438 [IEEE80211_MODE_TURBO_G] = IEEE80211_CHAN_G,
439 [IEEE80211_MODE_STURBO_A] = IEEE80211_CHAN_ST,
440 [IEEE80211_MODE_HALF] = IEEE80211_CHAN_HALF,
441 [IEEE80211_MODE_QUARTER] = IEEE80211_CHAN_QUARTER,
442 /* check legacy */
443 [IEEE80211_MODE_11NA] = IEEE80211_CHAN_A,
444 [IEEE80211_MODE_11NG] = IEEE80211_CHAN_G,
445 };
446
447 static void
448 add_channels(struct ieee80211vap *vap,
449 struct ieee80211_scan_state *ss,
450 enum ieee80211_phymode mode, const uint16_t freq[], int nfreq)
451 {
452 #define N(a) (sizeof(a) / sizeof(a[0]))
453 struct ieee80211com *ic = vap->iv_ic;
454 struct ieee80211_channel *c, *cg;
455 u_int modeflags;
456 int i;
457
458 KASSERT(mode < N(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 #undef N
479 }
480
481 struct scanlist {
482 uint16_t mode;
483 uint16_t count;
484 const uint16_t *list;
485 };
486
487 static int
488 checktable(const struct scanlist *scan, const struct ieee80211_channel *c)
489 {
490 int i;
491
492 for (; scan->list != NULL; scan++) {
493 for (i = 0; i < scan->count; i++)
494 if (scan->list[i] == c->ic_freq)
495 return 1;
496 }
497 return 0;
498 }
499
500 static int
501 onscanlist(const struct ieee80211_scan_state *ss,
502 const struct ieee80211_channel *c)
503 {
504 int i;
505
506 for (i = 0; i < ss->ss_last; i++)
507 if (ss->ss_chans[i] == c)
508 return 1;
509 return 0;
510 }
511
512 static void
513 sweepchannels(struct ieee80211_scan_state *ss, struct ieee80211vap *vap,
514 const struct scanlist table[])
515 {
516 struct ieee80211com *ic = vap->iv_ic;
517 struct ieee80211_channel *c;
518 int i;
519
520 for (i = 0; i < ic->ic_nchans; i++) {
521 if (ss->ss_last >= IEEE80211_SCAN_MAX)
522 break;
523
524 c = &ic->ic_channels[i];
525 /*
526 * Ignore dynamic turbo channels; we scan them
527 * in normal mode (i.e. not boosted). Likewise
528 * for HT channels, they get scanned using
529 * legacy rates.
530 */
531 if (IEEE80211_IS_CHAN_DTURBO(c) || IEEE80211_IS_CHAN_HT(c))
532 continue;
533
534 /*
535 * If a desired mode was specified, scan only
536 * channels that satisfy that constraint.
537 */
538 if (vap->iv_des_mode != IEEE80211_MODE_AUTO &&
539 vap->iv_des_mode != ieee80211_chan2mode(c))
540 continue;
541
542 /*
543 * Skip channels excluded by user request.
544 */
545 if (isexcluded(vap, c))
546 continue;
547
548 /*
549 * Add the channel unless it is listed in the
550 * fixed scan order tables. This insures we
551 * don't sweep back in channels we filtered out
552 * above.
553 */
554 if (checktable(table, c))
555 continue;
556
557 /* Add channel to scanning list. */
558 ss->ss_chans[ss->ss_last++] = c;
559 }
560 /*
561 * Explicitly add any desired channel if:
562 * - not already on the scan list
563 * - allowed by any desired mode constraint
564 * - there is space in the scan list
565 * This allows the channel to be used when the filtering
566 * mechanisms would otherwise elide it (e.g HT, turbo).
567 */
568 c = vap->iv_des_chan;
569 if (c != IEEE80211_CHAN_ANYC &&
570 !onscanlist(ss, c) &&
571 (vap->iv_des_mode == IEEE80211_MODE_AUTO ||
572 vap->iv_des_mode == ieee80211_chan2mode(c)) &&
573 ss->ss_last < IEEE80211_SCAN_MAX)
574 ss->ss_chans[ss->ss_last++] = c;
575 }
576
577 static void
578 makescanlist(struct ieee80211_scan_state *ss, struct ieee80211vap *vap,
579 const struct scanlist table[])
580 {
581 const struct scanlist *scan;
582 enum ieee80211_phymode mode;
583
584 ss->ss_last = 0;
585 /*
586 * Use the table of ordered channels to construct the list
587 * of channels for scanning. Any channels in the ordered
588 * list not in the master list will be discarded.
589 */
590 for (scan = table; scan->list != NULL; scan++) {
591 mode = scan->mode;
592 if (vap->iv_des_mode != IEEE80211_MODE_AUTO) {
593 /*
594 * If a desired mode was specified, scan only
595 * channels that satisfy that constraint.
596 */
597 if (vap->iv_des_mode != mode) {
598 /*
599 * The scan table marks 2.4Ghz channels as b
600 * so if the desired mode is 11g, then use
601 * the 11b channel list but upgrade the mode.
602 */
603 if (vap->iv_des_mode != IEEE80211_MODE_11G ||
604 mode != IEEE80211_MODE_11B)
605 continue;
606 mode = IEEE80211_MODE_11G; /* upgrade */
607 }
608 } else {
609 /*
610 * This lets add_channels upgrade an 11b channel
611 * to 11g if available.
612 */
613 if (mode == IEEE80211_MODE_11B)
614 mode = IEEE80211_MODE_AUTO;
615 }
616 #ifdef IEEE80211_F_XR
617 /* XR does not operate on turbo channels */
618 if ((vap->iv_flags & IEEE80211_F_XR) &&
619 (mode == IEEE80211_MODE_TURBO_A ||
620 mode == IEEE80211_MODE_TURBO_G ||
621 mode == IEEE80211_MODE_STURBO_A))
622 continue;
623 #endif
624 /*
625 * Add the list of the channels; any that are not
626 * in the master channel list will be discarded.
627 */
628 add_channels(vap, ss, mode, scan->list, scan->count);
629 }
630
631 /*
632 * Add the channels from the ic that are not present
633 * in the table.
634 */
635 sweepchannels(ss, vap, table);
636 }
637
638 static const uint16_t rcl1[] = /* 8 FCC channel: 52, 56, 60, 64, 36, 40, 44, 48 */
639 { 5260, 5280, 5300, 5320, 5180, 5200, 5220, 5240 };
640 static const uint16_t rcl2[] = /* 4 MKK channels: 34, 38, 42, 46 */
641 { 5170, 5190, 5210, 5230 };
642 static const uint16_t rcl3[] = /* 2.4Ghz ch: 1,6,11,7,13 */
643 { 2412, 2437, 2462, 2442, 2472 };
644 static const uint16_t rcl4[] = /* 5 FCC channel: 149, 153, 161, 165 */
645 { 5745, 5765, 5785, 5805, 5825 };
646 static const uint16_t rcl7[] = /* 11 ETSI channel: 100,104,108,112,116,120,124,128,132,136,140 */
647 { 5500, 5520, 5540, 5560, 5580, 5600, 5620, 5640, 5660, 5680, 5700 };
648 static const uint16_t rcl8[] = /* 2.4Ghz ch: 2,3,4,5,8,9,10,12 */
649 { 2417, 2422, 2427, 2432, 2447, 2452, 2457, 2467 };
650 static const uint16_t rcl9[] = /* 2.4Ghz ch: 14 */
651 { 2484 };
652 static const uint16_t rcl10[] = /* Added Korean channels 2312-2372 */
653 { 2312, 2317, 2322, 2327, 2332, 2337, 2342, 2347, 2352, 2357, 2362, 2367, 2372 };
654 static const uint16_t rcl11[] = /* Added Japan channels in 4.9/5.0 spectrum */
655 { 5040, 5060, 5080, 4920, 4940, 4960, 4980 };
656 #ifdef ATH_TURBO_SCAN
657 static const uint16_t rcl5[] = /* 3 static turbo channels */
658 { 5210, 5250, 5290 };
659 static const uint16_t rcl6[] = /* 2 static turbo channels */
660 { 5760, 5800 };
661 static const uint16_t rcl6x[] = /* 4 FCC3 turbo channels */
662 { 5540, 5580, 5620, 5660 };
663 static const uint16_t rcl12[] = /* 2.4Ghz Turbo channel 6 */
664 { 2437 };
665 static const uint16_t rcl13[] = /* dynamic Turbo channels */
666 { 5200, 5240, 5280, 5765, 5805 };
667 #endif /* ATH_TURBO_SCAN */
668
669 #define X(a) .count = sizeof(a)/sizeof(a[0]), .list = a
670
671 static const struct scanlist staScanTable[] = {
672 { IEEE80211_MODE_11B, X(rcl3) },
673 { IEEE80211_MODE_11A, X(rcl1) },
674 { IEEE80211_MODE_11A, X(rcl2) },
675 { IEEE80211_MODE_11B, X(rcl8) },
676 { IEEE80211_MODE_11B, X(rcl9) },
677 { IEEE80211_MODE_11A, X(rcl4) },
678 #ifdef ATH_TURBO_SCAN
679 { IEEE80211_MODE_STURBO_A, X(rcl5) },
680 { IEEE80211_MODE_STURBO_A, X(rcl6) },
681 { IEEE80211_MODE_TURBO_A, X(rcl6x) },
682 { IEEE80211_MODE_TURBO_A, X(rcl13) },
683 #endif /* ATH_TURBO_SCAN */
684 { IEEE80211_MODE_11A, X(rcl7) },
685 { IEEE80211_MODE_11B, X(rcl10) },
686 { IEEE80211_MODE_11A, X(rcl11) },
687 #ifdef ATH_TURBO_SCAN
688 { IEEE80211_MODE_TURBO_G, X(rcl12) },
689 #endif /* ATH_TURBO_SCAN */
690 { .list = NULL }
691 };
692
693 /*
694 * Start a station-mode scan by populating the channel list.
695 */
696 static int
697 sta_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
698 {
699 struct sta_table *st = ss->ss_priv;
700
701 makescanlist(ss, vap, staScanTable);
702
703 if (ss->ss_mindwell == 0)
704 ss->ss_mindwell = msecs_to_ticks(20); /* 20ms */
705 if (ss->ss_maxdwell == 0)
706 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
707
708 st->st_scangen++;
709 st->st_newscan = 1;
710
711 return 0;
712 }
713
714 /*
715 * Restart a scan, typically a bg scan but can
716 * also be a fg scan that came up empty.
717 */
718 static int
719 sta_restart(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
720 {
721 struct sta_table *st = ss->ss_priv;
722
723 st->st_newscan = 1;
724 return 0;
725 }
726
727 /*
728 * Cancel an ongoing scan.
729 */
730 static int
731 sta_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
732 {
733 return 0;
734 }
735
736 /* unalligned little endian access */
737 #define LE_READ_2(p) \
738 ((uint16_t) \
739 ((((const uint8_t *)(p))[0] ) | \
740 (((const uint8_t *)(p))[1] << 8)))
741
742 /*
743 * Demote any supplied 11g channel to 11b. There should
744 * always be an 11b channel but we check anyway...
745 */
746 static struct ieee80211_channel *
747 demote11b(struct ieee80211vap *vap, struct ieee80211_channel *chan)
748 {
749 struct ieee80211_channel *c;
750
751 if (IEEE80211_IS_CHAN_ANYG(chan) &&
752 vap->iv_des_mode == IEEE80211_MODE_AUTO) {
753 c = ieee80211_find_channel(vap->iv_ic, chan->ic_freq,
754 (chan->ic_flags &~ (IEEE80211_CHAN_PUREG | IEEE80211_CHAN_G)) |
755 IEEE80211_CHAN_B);
756 if (c != NULL)
757 chan = c;
758 }
759 return chan;
760 }
761
762 static int
763 maxrate(const struct ieee80211_scan_entry *se)
764 {
765 const struct ieee80211_ie_htcap *htcap =
766 (const struct ieee80211_ie_htcap *) se->se_ies.htcap_ie;
767 int rmax, r, i, txstream;
768 uint16_t caps;
769 uint8_t txparams;
770
771 rmax = 0;
772 if (htcap != NULL) {
773 /*
774 * HT station; inspect supported MCS and then adjust
775 * rate by channel width.
776 */
777 txparams = htcap->hc_mcsset[12];
778 if (txparams & 0x3) {
779 /*
780 * TX MCS parameters defined and not equal to RX,
781 * extract the number of spartial streams and
782 * map it to the highest MCS rate.
783 */
784 txstream = ((txparams & 0xc) >> 2) + 1;
785 i = txstream * 8 - 1;
786 } else
787 for (i = 31; i >= 0 && isclr(htcap->hc_mcsset, i); i--);
788 if (i >= 0) {
789 caps = LE_READ_2(&htcap->hc_cap);
790 if ((caps & IEEE80211_HTCAP_CHWIDTH40) &&
791 (caps & IEEE80211_HTCAP_SHORTGI40))
792 rmax = ieee80211_htrates[i].ht40_rate_400ns;
793 else if (caps & IEEE80211_HTCAP_CHWIDTH40)
794 rmax = ieee80211_htrates[i].ht40_rate_800ns;
795 else if (caps & IEEE80211_HTCAP_SHORTGI20)
796 rmax = ieee80211_htrates[i].ht20_rate_400ns;
797 else
798 rmax = ieee80211_htrates[i].ht20_rate_800ns;
799 }
800 }
801 for (i = 0; i < se->se_rates[1]; i++) {
802 r = se->se_rates[2+i] & IEEE80211_RATE_VAL;
803 if (r > rmax)
804 rmax = r;
805 }
806 for (i = 0; i < se->se_xrates[1]; i++) {
807 r = se->se_xrates[2+i] & IEEE80211_RATE_VAL;
808 if (r > rmax)
809 rmax = r;
810 }
811 return rmax;
812 }
813
814 /*
815 * Compare the capabilities of two entries and decide which is
816 * more desirable (return >0 if a is considered better). Note
817 * that we assume compatibility/usability has already been checked
818 * so we don't need to (e.g. validate whether privacy is supported).
819 * Used to select the best scan candidate for association in a BSS.
820 */
821 static int
822 sta_compare(const struct sta_entry *a, const struct sta_entry *b)
823 {
824 #define PREFER(_a,_b,_what) do { \
825 if (((_a) ^ (_b)) & (_what)) \
826 return ((_a) & (_what)) ? 1 : -1; \
827 } while (0)
828 int maxa, maxb;
829 int8_t rssia, rssib;
830 int weight;
831
832 /* privacy support */
833 PREFER(a->base.se_capinfo, b->base.se_capinfo,
834 IEEE80211_CAPINFO_PRIVACY);
835
836 /* compare count of previous failures */
837 weight = b->se_fails - a->se_fails;
838 if (abs(weight) > 1)
839 return weight;
840
841 /*
842 * Compare rssi. If the two are considered equivalent
843 * then fallback to other criteria. We threshold the
844 * comparisons to avoid selecting an ap purely by rssi
845 * when both values may be good but one ap is otherwise
846 * more desirable (e.g. an 11b-only ap with stronger
847 * signal than an 11g ap).
848 */
849 rssia = MIN(a->base.se_rssi, STA_RSSI_MAX);
850 rssib = MIN(b->base.se_rssi, STA_RSSI_MAX);
851 if (abs(rssib - rssia) < 5) {
852 /* best/max rate preferred if signal level close enough XXX */
853 maxa = maxrate(&a->base);
854 maxb = maxrate(&b->base);
855 if (maxa != maxb)
856 return maxa - maxb;
857 /* XXX use freq for channel preference */
858 /* for now just prefer 5Ghz band to all other bands */
859 PREFER(IEEE80211_IS_CHAN_5GHZ(a->base.se_chan),
860 IEEE80211_IS_CHAN_5GHZ(b->base.se_chan), 1);
861 }
862 /* all things being equal, use signal level */
863 return a->base.se_rssi - b->base.se_rssi;
864 #undef PREFER
865 }
866
867 /*
868 * Check rate set suitability and return the best supported rate.
869 * XXX inspect MCS for HT
870 */
871 static int
872 check_rate(struct ieee80211vap *vap, const struct ieee80211_channel *chan,
873 const struct ieee80211_scan_entry *se)
874 {
875 #define RV(v) ((v) & IEEE80211_RATE_VAL)
876 const struct ieee80211_rateset *srs;
877 int i, j, nrs, r, okrate, badrate, fixedrate, ucastrate;
878 const uint8_t *rs;
879
880 okrate = badrate = 0;
881
882 srs = ieee80211_get_suprates(vap->iv_ic, chan);
883 nrs = se->se_rates[1];
884 rs = se->se_rates+2;
885 /* XXX MCS */
886 ucastrate = vap->iv_txparms[ieee80211_chan2mode(chan)].ucastrate;
887 fixedrate = IEEE80211_FIXED_RATE_NONE;
888 again:
889 for (i = 0; i < nrs; i++) {
890 r = RV(rs[i]);
891 badrate = r;
892 /*
893 * Check any fixed rate is included.
894 */
895 if (r == ucastrate)
896 fixedrate = r;
897 /*
898 * Check against our supported rates.
899 */
900 for (j = 0; j < srs->rs_nrates; j++)
901 if (r == RV(srs->rs_rates[j])) {
902 if (r > okrate) /* NB: track max */
903 okrate = r;
904 break;
905 }
906
907 if (j == srs->rs_nrates && (rs[i] & IEEE80211_RATE_BASIC)) {
908 /*
909 * Don't try joining a BSS, if we don't support
910 * one of its basic rates.
911 */
912 okrate = 0;
913 goto back;
914 }
915 }
916 if (rs == se->se_rates+2) {
917 /* scan xrates too; sort of an algol68-style for loop */
918 nrs = se->se_xrates[1];
919 rs = se->se_xrates+2;
920 goto again;
921 }
922
923 back:
924 if (okrate == 0 || ucastrate != fixedrate)
925 return badrate | IEEE80211_RATE_BASIC;
926 else
927 return RV(okrate);
928 #undef RV
929 }
930
931 static __inline int
932 match_id(const uint8_t *ie, const uint8_t *val, int len)
933 {
934 return (ie[1] == len && memcmp(ie+2, val, len) == 0);
935 }
936
937 static int
938 match_ssid(const uint8_t *ie,
939 int nssid, const struct ieee80211_scan_ssid ssids[])
940 {
941 int i;
942
943 for (i = 0; i < nssid; i++) {
944 if (match_id(ie, ssids[i].ssid, ssids[i].len))
945 return 1;
946 }
947 return 0;
948 }
949
950 #ifdef IEEE80211_SUPPORT_TDMA
951 static int
952 tdma_isfull(const struct ieee80211_tdma_param *tdma)
953 {
954 int slot, slotcnt;
955
956 slotcnt = tdma->tdma_slotcnt;
957 for (slot = slotcnt-1; slot >= 0; slot--)
958 if (isclr(tdma->tdma_inuse, slot))
959 return 0;
960 return 1;
961 }
962 #endif /* IEEE80211_SUPPORT_TDMA */
963
964 /*
965 * Test a scan candidate for suitability/compatibility.
966 */
967 static int
968 match_bss(struct ieee80211vap *vap,
969 const struct ieee80211_scan_state *ss, struct sta_entry *se0,
970 int debug)
971 {
972 struct ieee80211com *ic = vap->iv_ic;
973 struct ieee80211_scan_entry *se = &se0->base;
974 uint8_t rate;
975 int fail;
976
977 fail = 0;
978 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, se->se_chan)))
979 fail |= MATCH_CHANNEL;
980 /*
981 * NB: normally the desired mode is used to construct
982 * the channel list, but it's possible for the scan
983 * cache to include entries for stations outside this
984 * list so we check the desired mode here to weed them
985 * out.
986 */
987 if (vap->iv_des_mode != IEEE80211_MODE_AUTO &&
988 (se->se_chan->ic_flags & IEEE80211_CHAN_ALLTURBO) !=
989 chanflags[vap->iv_des_mode])
990 fail |= MATCH_CHANNEL;
991 if (vap->iv_opmode == IEEE80211_M_IBSS) {
992 if ((se->se_capinfo & IEEE80211_CAPINFO_IBSS) == 0)
993 fail |= MATCH_CAPINFO;
994 #ifdef IEEE80211_SUPPORT_TDMA
995 } else if (vap->iv_opmode == IEEE80211_M_AHDEMO) {
996 /*
997 * Adhoc demo network setup shouldn't really be scanning
998 * but just in case skip stations operating in IBSS or
999 * BSS mode.
1000 */
1001 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS))
1002 fail |= MATCH_CAPINFO;
1003 /*
1004 * TDMA operation cannot coexist with a normal 802.11 network;
1005 * skip if IBSS or ESS capabilities are marked and require
1006 * the beacon have a TDMA ie present.
1007 */
1008 if (vap->iv_caps & IEEE80211_C_TDMA) {
1009 const struct ieee80211_tdma_param *tdma =
1010 (const struct ieee80211_tdma_param *)se->se_ies.tdma_ie;
1011 const struct ieee80211_tdma_state *ts = vap->iv_tdma;
1012
1013 if (tdma == NULL)
1014 fail |= MATCH_TDMA_NOIE;
1015 else if (tdma->tdma_version != ts->tdma_version)
1016 fail |= MATCH_TDMA_VERSION;
1017 else if (tdma->tdma_slot != 0)
1018 fail |= MATCH_TDMA_NOTMASTER;
1019 else if (tdma_isfull(tdma))
1020 fail |= MATCH_TDMA_NOSLOT;
1021 #if 0
1022 else if (ieee80211_local_address(se->se_macaddr))
1023 fail |= MATCH_TDMA_LOCAL;
1024 #endif
1025 }
1026 #endif /* IEEE80211_SUPPORT_TDMA */
1027 #ifdef IEEE80211_SUPPORT_MESH
1028 } else if (vap->iv_opmode == IEEE80211_M_MBSS) {
1029 const struct ieee80211_mesh_state *ms = vap->iv_mesh;
1030 /*
1031 * Mesh nodes have IBSS & ESS bits in capinfo turned off
1032 * and two special ie's that must be present.
1033 */
1034 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS))
1035 fail |= MATCH_CAPINFO;
1036 else if (se->se_meshid[0] != IEEE80211_ELEMID_MESHID)
1037 fail |= MATCH_MESH_NOID;
1038 else if (ms->ms_idlen != 0 &&
1039 match_id(se->se_meshid, ms->ms_id, ms->ms_idlen))
1040 fail |= MATCH_MESHID;
1041 #endif
1042 } else {
1043 if ((se->se_capinfo & IEEE80211_CAPINFO_ESS) == 0)
1044 fail |= MATCH_CAPINFO;
1045 /*
1046 * If 11d is enabled and we're attempting to join a bss
1047 * that advertises it's country code then compare our
1048 * current settings to what we fetched from the country ie.
1049 * If our country code is unspecified or different then do
1050 * not attempt to join the bss. We should have already
1051 * dispatched an event to user space that identifies the
1052 * new country code so our regdomain config should match.
1053 */
1054 if ((IEEE80211_IS_CHAN_11D(se->se_chan) ||
1055 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) &&
1056 se->se_cc[0] != 0 &&
1057 (ic->ic_regdomain.country == CTRY_DEFAULT ||
1058 !isocmp(se->se_cc, ic->ic_regdomain.isocc)))
1059 fail |= MATCH_CC;
1060 }
1061 if (vap->iv_flags & IEEE80211_F_PRIVACY) {
1062 if ((se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0)
1063 fail |= MATCH_PRIVACY;
1064 } else {
1065 /* XXX does this mean privacy is supported or required? */
1066 if (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY)
1067 fail |= MATCH_PRIVACY;
1068 }
1069 se0->se_flags &= ~STA_DEMOTE11B;
1070 rate = check_rate(vap, se->se_chan, se);
1071 if (rate & IEEE80211_RATE_BASIC) {
1072 fail |= MATCH_RATE;
1073 /*
1074 * An 11b-only ap will give a rate mismatch if there is an
1075 * OFDM fixed tx rate for 11g. Try downgrading the channel
1076 * in the scan list to 11b and retry the rate check.
1077 */
1078 if (IEEE80211_IS_CHAN_ANYG(se->se_chan)) {
1079 rate = check_rate(vap, demote11b(vap, se->se_chan), se);
1080 if ((rate & IEEE80211_RATE_BASIC) == 0) {
1081 fail &= ~MATCH_RATE;
1082 se0->se_flags |= STA_DEMOTE11B;
1083 }
1084 }
1085 } else if (rate < 2*24) {
1086 /*
1087 * This is an 11b-only ap. Check the desired mode in
1088 * case that needs to be honored (mode 11g filters out
1089 * 11b-only ap's). Otherwise force any 11g channel used
1090 * in scanning to be demoted.
1091 *
1092 * NB: we cheat a bit here by looking at the max rate;
1093 * we could/should check the rates.
1094 */
1095 if (!(vap->iv_des_mode == IEEE80211_MODE_AUTO ||
1096 vap->iv_des_mode == IEEE80211_MODE_11B))
1097 fail |= MATCH_RATE;
1098 else
1099 se0->se_flags |= STA_DEMOTE11B;
1100 }
1101 if (ss->ss_nssid != 0 &&
1102 !match_ssid(se->se_ssid, ss->ss_nssid, ss->ss_ssid))
1103 fail |= MATCH_SSID;
1104 if ((vap->iv_flags & IEEE80211_F_DESBSSID) &&
1105 !IEEE80211_ADDR_EQ(vap->iv_des_bssid, se->se_bssid))
1106 fail |= MATCH_BSSID;
1107 if (se0->se_fails >= STA_FAILS_MAX)
1108 fail |= MATCH_FAILS;
1109 if (se0->se_notseen >= STA_PURGE_SCANS)
1110 fail |= MATCH_NOTSEEN;
1111 if (se->se_rssi < STA_RSSI_MIN)
1112 fail |= MATCH_RSSI;
1113 #ifdef IEEE80211_DEBUG
1114 if (ieee80211_msg(vap, debug)) {
1115 printf(" %c %s",
1116 fail & MATCH_FAILS ? '=' :
1117 fail & MATCH_NOTSEEN ? '^' :
1118 fail & MATCH_CC ? '$' :
1119 #ifdef IEEE80211_SUPPORT_TDMA
1120 fail & MATCH_TDMA_NOIE ? '&' :
1121 fail & MATCH_TDMA_VERSION ? 'v' :
1122 fail & MATCH_TDMA_NOTMASTER ? 's' :
1123 fail & MATCH_TDMA_NOSLOT ? 'f' :
1124 fail & MATCH_TDMA_LOCAL ? 'l' :
1125 #endif
1126 fail & MATCH_MESH_NOID ? 'm' :
1127 fail ? '-' : '+', ether_sprintf(se->se_macaddr));
1128 printf(" %s%c", ether_sprintf(se->se_bssid),
1129 fail & MATCH_BSSID ? '!' : ' ');
1130 printf(" %3d%c", ieee80211_chan2ieee(ic, se->se_chan),
1131 fail & MATCH_CHANNEL ? '!' : ' ');
1132 printf(" %+4d%c", se->se_rssi, fail & MATCH_RSSI ? '!' : ' ');
1133 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2,
1134 fail & MATCH_RATE ? '!' : ' ');
1135 printf(" %4s%c",
1136 (se->se_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" :
1137 (se->se_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : "",
1138 fail & MATCH_CAPINFO ? '!' : ' ');
1139 printf(" %3s%c ",
1140 (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) ?
1141 "wep" : "no",
1142 fail & MATCH_PRIVACY ? '!' : ' ');
1143 ieee80211_print_essid(se->se_ssid+2, se->se_ssid[1]);
1144 printf("%s\n", fail & (MATCH_SSID | MATCH_MESHID) ? "!" : "");
1145 }
1146 #endif
1147 return fail;
1148 }
1149
1150 static void
1151 sta_update_notseen(struct sta_table *st)
1152 {
1153 struct sta_entry *se;
1154
1155 IEEE80211_SCAN_TABLE_LOCK(st);
1156 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1157 /*
1158 * If seen the reset and don't bump the count;
1159 * otherwise bump the ``not seen'' count. Note
1160 * that this insures that stations for which we
1161 * see frames while not scanning but not during
1162 * this scan will not be penalized.
1163 */
1164 if (se->se_seen)
1165 se->se_seen = 0;
1166 else
1167 se->se_notseen++;
1168 }
1169 IEEE80211_SCAN_TABLE_UNLOCK(st);
1170 }
1171
1172 static void
1173 sta_dec_fails(struct sta_table *st)
1174 {
1175 struct sta_entry *se;
1176
1177 IEEE80211_SCAN_TABLE_LOCK(st);
1178 TAILQ_FOREACH(se, &st->st_entry, se_list)
1179 if (se->se_fails)
1180 se->se_fails--;
1181 IEEE80211_SCAN_TABLE_UNLOCK(st);
1182 }
1183
1184 static struct sta_entry *
1185 select_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, int debug)
1186 {
1187 struct sta_table *st = ss->ss_priv;
1188 struct sta_entry *se, *selbs = NULL;
1189
1190 IEEE80211_DPRINTF(vap, debug, " %s\n",
1191 "macaddr bssid chan rssi rate flag wep essid");
1192 IEEE80211_SCAN_TABLE_LOCK(st);
1193 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1194 ieee80211_ies_expand(&se->base.se_ies);
1195 if (match_bss(vap, ss, se, debug) == 0) {
1196 if (selbs == NULL)
1197 selbs = se;
1198 else if (sta_compare(se, selbs) > 0)
1199 selbs = se;
1200 }
1201 }
1202 IEEE80211_SCAN_TABLE_UNLOCK(st);
1203
1204 return selbs;
1205 }
1206
1207 /*
1208 * Pick an ap or ibss network to join or find a channel
1209 * to use to start an ibss network.
1210 */
1211 static int
1212 sta_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1213 {
1214 struct sta_table *st = ss->ss_priv;
1215 struct sta_entry *selbs;
1216 struct ieee80211_channel *chan;
1217
1218 KASSERT(vap->iv_opmode == IEEE80211_M_STA,
1219 ("wrong mode %u", vap->iv_opmode));
1220
1221 if (st->st_newscan) {
1222 sta_update_notseen(st);
1223 st->st_newscan = 0;
1224 }
1225 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1226 /*
1227 * Manual/background scan, don't select+join the
1228 * bss, just return. The scanning framework will
1229 * handle notification that this has completed.
1230 */
1231 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1232 return 1;
1233 }
1234 /*
1235 * Automatic sequencing; look for a candidate and
1236 * if found join the network.
1237 */
1238 /* NB: unlocked read should be ok */
1239 if (TAILQ_FIRST(&st->st_entry) == NULL) {
1240 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1241 "%s: no scan candidate\n", __func__);
1242 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1243 return 0;
1244 notfound:
1245 /*
1246 * If nothing suitable was found decrement
1247 * the failure counts so entries will be
1248 * reconsidered the next time around. We
1249 * really want to do this only for sta's
1250 * where we've previously had some success.
1251 */
1252 sta_dec_fails(st);
1253 st->st_newscan = 1;
1254 return 0; /* restart scan */
1255 }
1256 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1257 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1258 return (selbs != NULL);
1259 if (selbs == NULL)
1260 goto notfound;
1261 chan = selbs->base.se_chan;
1262 if (selbs->se_flags & STA_DEMOTE11B)
1263 chan = demote11b(vap, chan);
1264 if (!ieee80211_sta_join(vap, chan, &selbs->base))
1265 goto notfound;
1266 return 1; /* terminate scan */
1267 }
1268
1269 /*
1270 * Lookup an entry in the scan cache. We assume we're
1271 * called from the bottom half or such that we don't need
1272 * to block the bottom half so that it's safe to return
1273 * a reference to an entry w/o holding the lock on the table.
1274 */
1275 static struct sta_entry *
1276 sta_lookup(struct sta_table *st, const uint8_t macaddr[IEEE80211_ADDR_LEN])
1277 {
1278 struct sta_entry *se;
1279 int hash = STA_HASH(macaddr);
1280
1281 IEEE80211_SCAN_TABLE_LOCK(st);
1282 LIST_FOREACH(se, &st->st_hash[hash], se_hash)
1283 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr))
1284 break;
1285 IEEE80211_SCAN_TABLE_UNLOCK(st);
1286
1287 return se; /* NB: unlocked */
1288 }
1289
1290 static void
1291 sta_roam_check(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1292 {
1293 struct ieee80211com *ic = vap->iv_ic;
1294 struct ieee80211_node *ni = vap->iv_bss;
1295 struct sta_table *st = ss->ss_priv;
1296 enum ieee80211_phymode mode;
1297 struct sta_entry *se, *selbs;
1298 uint8_t roamRate, curRate, ucastRate;
1299 int8_t roamRssi, curRssi;
1300
1301 se = sta_lookup(st, ni->ni_macaddr);
1302 if (se == NULL) {
1303 /* XXX something is wrong */
1304 return;
1305 }
1306
1307 mode = ieee80211_chan2mode(ic->ic_bsschan);
1308 roamRate = vap->iv_roamparms[mode].rate;
1309 roamRssi = vap->iv_roamparms[mode].rssi;
1310 ucastRate = vap->iv_txparms[mode].ucastrate;
1311 /* NB: the most up to date rssi is in the node, not the scan cache */
1312 curRssi = ic->ic_node_getrssi(ni);
1313 if (ucastRate == IEEE80211_FIXED_RATE_NONE) {
1314 curRate = ni->ni_txrate;
1315 roamRate &= IEEE80211_RATE_VAL;
1316 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM,
1317 "%s: currssi %d currate %u roamrssi %d roamrate %u\n",
1318 __func__, curRssi, curRate, roamRssi, roamRate);
1319 } else {
1320 curRate = roamRate; /* NB: insure compare below fails */
1321 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM,
1322 "%s: currssi %d roamrssi %d\n", __func__, curRssi, roamRssi);
1323 }
1324 /*
1325 * Check if a new ap should be used and switch.
1326 * XXX deauth current ap
1327 */
1328 if (curRate < roamRate || curRssi < roamRssi) {
1329 if (time_after(ticks, ic->ic_lastscan + vap->iv_scanvalid)) {
1330 /*
1331 * Scan cache contents are too old; force a scan now
1332 * if possible so we have current state to make a
1333 * decision with. We don't kick off a bg scan if
1334 * we're using dynamic turbo and boosted or if the
1335 * channel is busy.
1336 * XXX force immediate switch on scan complete
1337 */
1338 if (!IEEE80211_IS_CHAN_DTURBO(ic->ic_curchan) &&
1339 time_after(ticks, ic->ic_lastdata + vap->iv_bgscanidle))
1340 ieee80211_bg_scan(vap, 0);
1341 return;
1342 }
1343 se->base.se_rssi = curRssi;
1344 selbs = select_bss(ss, vap, IEEE80211_MSG_ROAM);
1345 if (selbs != NULL && selbs != se) {
1346 struct ieee80211_channel *chan;
1347
1348 IEEE80211_DPRINTF(vap,
1349 IEEE80211_MSG_ROAM | IEEE80211_MSG_DEBUG,
1350 "%s: ROAM: curRate %u, roamRate %u, "
1351 "curRssi %d, roamRssi %d\n", __func__,
1352 curRate, roamRate, curRssi, roamRssi);
1353
1354 chan = selbs->base.se_chan;
1355 if (selbs->se_flags & STA_DEMOTE11B)
1356 chan = demote11b(vap, chan);
1357 (void) ieee80211_sta_join(vap, chan, &selbs->base);
1358 }
1359 }
1360 }
1361
1362 /*
1363 * Age entries in the scan cache.
1364 * XXX also do roaming since it's convenient
1365 */
1366 static void
1367 sta_age(struct ieee80211_scan_state *ss)
1368 {
1369 struct ieee80211vap *vap = ss->ss_vap;
1370
1371 adhoc_age(ss);
1372 /*
1373 * If rate control is enabled check periodically to see if
1374 * we should roam from our current connection to one that
1375 * might be better. This only applies when we're operating
1376 * in sta mode and automatic roaming is set.
1377 * XXX defer if busy
1378 * XXX repeater station
1379 * XXX do when !bgscan?
1380 */
1381 KASSERT(vap->iv_opmode == IEEE80211_M_STA,
1382 ("wrong mode %u", vap->iv_opmode));
1383 if (vap->iv_roaming == IEEE80211_ROAMING_AUTO &&
1384 (vap->iv_flags & IEEE80211_F_BGSCAN) &&
1385 vap->iv_state >= IEEE80211_S_RUN)
1386 /* XXX vap is implicit */
1387 sta_roam_check(ss, vap);
1388 }
1389
1390 /*
1391 * Iterate over the entries in the scan cache, invoking
1392 * the callback function on each one.
1393 */
1394 static void
1395 sta_iterate(struct ieee80211_scan_state *ss,
1396 ieee80211_scan_iter_func *f, void *arg)
1397 {
1398 struct sta_table *st = ss->ss_priv;
1399 struct sta_entry *se;
1400 u_int gen;
1401
1402 mtx_lock(&st->st_scanlock);
1403 gen = st->st_scaniter++;
1404 restart:
1405 IEEE80211_SCAN_TABLE_LOCK(st);
1406 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1407 if (se->se_scangen != gen) {
1408 se->se_scangen = gen;
1409 /* update public state */
1410 se->base.se_age = ticks - se->se_lastupdate;
1411 IEEE80211_SCAN_TABLE_UNLOCK(st);
1412 (*f)(arg, &se->base);
1413 goto restart;
1414 }
1415 }
1416 IEEE80211_SCAN_TABLE_UNLOCK(st);
1417
1418 mtx_unlock(&st->st_scanlock);
1419 }
1420
1421 static void
1422 sta_assoc_fail(struct ieee80211_scan_state *ss,
1423 const uint8_t macaddr[IEEE80211_ADDR_LEN], int reason)
1424 {
1425 struct sta_table *st = ss->ss_priv;
1426 struct sta_entry *se;
1427
1428 se = sta_lookup(st, macaddr);
1429 if (se != NULL) {
1430 se->se_fails++;
1431 se->se_lastfail = ticks;
1432 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN,
1433 macaddr, "%s: reason %u fails %u",
1434 __func__, reason, se->se_fails);
1435 }
1436 }
1437
1438 static void
1439 sta_assoc_success(struct ieee80211_scan_state *ss,
1440 const uint8_t macaddr[IEEE80211_ADDR_LEN])
1441 {
1442 struct sta_table *st = ss->ss_priv;
1443 struct sta_entry *se;
1444
1445 se = sta_lookup(st, macaddr);
1446 if (se != NULL) {
1447 #if 0
1448 se->se_fails = 0;
1449 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN,
1450 macaddr, "%s: fails %u",
1451 __func__, se->se_fails);
1452 #endif
1453 se->se_lastassoc = ticks;
1454 }
1455 }
1456
1457 static const struct ieee80211_scanner sta_default = {
1458 .scan_name = "default",
1459 .scan_attach = sta_attach,
1460 .scan_detach = sta_detach,
1461 .scan_start = sta_start,
1462 .scan_restart = sta_restart,
1463 .scan_cancel = sta_cancel,
1464 .scan_end = sta_pick_bss,
1465 .scan_flush = sta_flush,
1466 .scan_add = sta_add,
1467 .scan_age = sta_age,
1468 .scan_iterate = sta_iterate,
1469 .scan_assoc_fail = sta_assoc_fail,
1470 .scan_assoc_success = sta_assoc_success,
1471 };
1472 IEEE80211_SCANNER_ALG(sta, IEEE80211_M_STA, sta_default);
1473
1474 /*
1475 * Adhoc mode-specific support.
1476 */
1477
1478 static const uint16_t adhocWorld[] = /* 36, 40, 44, 48 */
1479 { 5180, 5200, 5220, 5240 };
1480 static const uint16_t adhocFcc3[] = /* 36, 40, 44, 48 145, 149, 153, 157, 161, 165 */
1481 { 5180, 5200, 5220, 5240, 5725, 5745, 5765, 5785, 5805, 5825 };
1482 static const uint16_t adhocMkk[] = /* 34, 38, 42, 46 */
1483 { 5170, 5190, 5210, 5230 };
1484 static const uint16_t adhoc11b[] = /* 10, 11 */
1485 { 2457, 2462 };
1486
1487 static const struct scanlist adhocScanTable[] = {
1488 { IEEE80211_MODE_11B, X(adhoc11b) },
1489 { IEEE80211_MODE_11A, X(adhocWorld) },
1490 { IEEE80211_MODE_11A, X(adhocFcc3) },
1491 { IEEE80211_MODE_11B, X(adhocMkk) },
1492 { .list = NULL }
1493 };
1494 #undef X
1495
1496 /*
1497 * Start an adhoc-mode scan by populating the channel list.
1498 */
1499 static int
1500 adhoc_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1501 {
1502 struct sta_table *st = ss->ss_priv;
1503
1504 makescanlist(ss, vap, adhocScanTable);
1505
1506 if (ss->ss_mindwell == 0)
1507 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */
1508 if (ss->ss_maxdwell == 0)
1509 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
1510
1511 st->st_scangen++;
1512 st->st_newscan = 1;
1513
1514 return 0;
1515 }
1516
1517 /*
1518 * Select a channel to start an adhoc network on.
1519 * The channel list was populated with appropriate
1520 * channels so select one that looks least occupied.
1521 */
1522 static struct ieee80211_channel *
1523 adhoc_pick_channel(struct ieee80211_scan_state *ss, int flags)
1524 {
1525 struct sta_table *st = ss->ss_priv;
1526 struct sta_entry *se;
1527 struct ieee80211_channel *c, *bestchan;
1528 int i, bestrssi, maxrssi;
1529
1530 bestchan = NULL;
1531 bestrssi = -1;
1532
1533 IEEE80211_SCAN_TABLE_LOCK(st);
1534 for (i = 0; i < ss->ss_last; i++) {
1535 c = ss->ss_chans[i];
1536 /* never consider a channel with radar */
1537 if (IEEE80211_IS_CHAN_RADAR(c))
1538 continue;
1539 /* skip channels disallowed by regulatory settings */
1540 if (IEEE80211_IS_CHAN_NOADHOC(c))
1541 continue;
1542 /* check channel attributes for band compatibility */
1543 if (flags != 0 && (c->ic_flags & flags) != flags)
1544 continue;
1545 maxrssi = 0;
1546 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1547 if (se->base.se_chan != c)
1548 continue;
1549 if (se->base.se_rssi > maxrssi)
1550 maxrssi = se->base.se_rssi;
1551 }
1552 if (bestchan == NULL || maxrssi < bestrssi)
1553 bestchan = c;
1554 }
1555 IEEE80211_SCAN_TABLE_UNLOCK(st);
1556
1557 return bestchan;
1558 }
1559
1560 /*
1561 * Pick an ibss network to join or find a channel
1562 * to use to start an ibss network.
1563 */
1564 static int
1565 adhoc_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1566 {
1567 struct sta_table *st = ss->ss_priv;
1568 struct sta_entry *selbs;
1569 struct ieee80211_channel *chan;
1570
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 struct ieee80211com *ic = vap->iv_ic;
1616
1617 chan = adhoc_pick_channel(ss, 0);
1618 if (chan != NULL)
1619 chan = ieee80211_ht_adjust_channel(ic,
1620 chan, vap->iv_flags_ht);
1621 } else
1622 chan = vap->iv_des_chan;
1623 if (chan != NULL) {
1624 ieee80211_create_ibss(vap, chan);
1625 return 1;
1626 }
1627 }
1628 /*
1629 * If nothing suitable was found decrement
1630 * the failure counts so entries will be
1631 * reconsidered the next time around. We
1632 * really want to do this only for sta's
1633 * where we've previously had some success.
1634 */
1635 sta_dec_fails(st);
1636 st->st_newscan = 1;
1637 return 0; /* restart scan */
1638 }
1639 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1640 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1641 return (selbs != NULL);
1642 if (selbs == NULL)
1643 goto notfound;
1644 chan = selbs->base.se_chan;
1645 if (selbs->se_flags & STA_DEMOTE11B)
1646 chan = demote11b(vap, chan);
1647 if (!ieee80211_sta_join(vap, chan, &selbs->base))
1648 goto notfound;
1649 return 1; /* terminate scan */
1650 }
1651
1652 /*
1653 * Age entries in the scan cache.
1654 */
1655 static void
1656 adhoc_age(struct ieee80211_scan_state *ss)
1657 {
1658 struct sta_table *st = ss->ss_priv;
1659 struct sta_entry *se, *next;
1660
1661 IEEE80211_SCAN_TABLE_LOCK(st);
1662 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) {
1663 if (se->se_notseen > STA_PURGE_SCANS) {
1664 TAILQ_REMOVE(&st->st_entry, se, se_list);
1665 LIST_REMOVE(se, se_hash);
1666 ieee80211_ies_cleanup(&se->base.se_ies);
1667 free(se, M_80211_SCAN);
1668 }
1669 }
1670 IEEE80211_SCAN_TABLE_UNLOCK(st);
1671 }
1672
1673 static const struct ieee80211_scanner adhoc_default = {
1674 .scan_name = "default",
1675 .scan_attach = sta_attach,
1676 .scan_detach = sta_detach,
1677 .scan_start = adhoc_start,
1678 .scan_restart = sta_restart,
1679 .scan_cancel = sta_cancel,
1680 .scan_end = adhoc_pick_bss,
1681 .scan_flush = sta_flush,
1682 .scan_pickchan = adhoc_pick_channel,
1683 .scan_add = sta_add,
1684 .scan_age = adhoc_age,
1685 .scan_iterate = sta_iterate,
1686 .scan_assoc_fail = sta_assoc_fail,
1687 .scan_assoc_success = sta_assoc_success,
1688 };
1689 IEEE80211_SCANNER_ALG(ibss, IEEE80211_M_IBSS, adhoc_default);
1690 IEEE80211_SCANNER_ALG(ahdemo, IEEE80211_M_AHDEMO, adhoc_default);
1691
1692 static void
1693 ap_force_promisc(struct ieee80211com *ic)
1694 {
1695 struct ifnet *ifp = ic->ic_ifp;
1696
1697 IEEE80211_LOCK(ic);
1698 /* set interface into promiscuous mode */
1699 ifp->if_flags |= IFF_PROMISC;
1700 ieee80211_runtask(ic, &ic->ic_promisc_task);
1701 IEEE80211_UNLOCK(ic);
1702 }
1703
1704 static void
1705 ap_reset_promisc(struct ieee80211com *ic)
1706 {
1707 IEEE80211_LOCK(ic);
1708 ieee80211_syncifflag_locked(ic, IFF_PROMISC);
1709 IEEE80211_UNLOCK(ic);
1710 }
1711
1712 static int
1713 ap_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1714 {
1715 struct sta_table *st = ss->ss_priv;
1716
1717 makescanlist(ss, vap, staScanTable);
1718
1719 if (ss->ss_mindwell == 0)
1720 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */
1721 if (ss->ss_maxdwell == 0)
1722 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
1723
1724 st->st_scangen++;
1725 st->st_newscan = 1;
1726
1727 ap_force_promisc(vap->iv_ic);
1728 return 0;
1729 }
1730
1731 /*
1732 * Cancel an ongoing scan.
1733 */
1734 static int
1735 ap_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1736 {
1737 ap_reset_promisc(vap->iv_ic);
1738 return 0;
1739 }
1740
1741 /*
1742 * Pick a quiet channel to use for ap operation.
1743 */
1744 static struct ieee80211_channel *
1745 ap_pick_channel(struct ieee80211_scan_state *ss, int flags)
1746 {
1747 struct sta_table *st = ss->ss_priv;
1748 struct ieee80211_channel *bestchan = NULL;
1749 int i;
1750
1751 /* XXX select channel more intelligently, e.g. channel spread, power */
1752 /* NB: use scan list order to preserve channel preference */
1753 for (i = 0; i < ss->ss_last; i++) {
1754 struct ieee80211_channel *chan = ss->ss_chans[i];
1755 /*
1756 * If the channel is unoccupied the max rssi
1757 * should be zero; just take it. Otherwise
1758 * track the channel with the lowest rssi and
1759 * use that when all channels appear occupied.
1760 */
1761 if (IEEE80211_IS_CHAN_RADAR(chan))
1762 continue;
1763 if (IEEE80211_IS_CHAN_NOHOSTAP(chan))
1764 continue;
1765 /* check channel attributes for band compatibility */
1766 if (flags != 0 && (chan->ic_flags & flags) != flags)
1767 continue;
1768 KASSERT(sizeof(chan->ic_ieee) == 1, ("ic_chan size"));
1769 /* XXX channel have interference */
1770 if (st->st_maxrssi[chan->ic_ieee] == 0) {
1771 /* XXX use other considerations */
1772 return chan;
1773 }
1774 if (bestchan == NULL ||
1775 st->st_maxrssi[chan->ic_ieee] < st->st_maxrssi[bestchan->ic_ieee])
1776 bestchan = chan;
1777 }
1778 return bestchan;
1779 }
1780
1781 /*
1782 * Pick a quiet channel to use for ap operation.
1783 */
1784 static int
1785 ap_end(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1786 {
1787 struct ieee80211com *ic = vap->iv_ic;
1788 struct ieee80211_channel *bestchan;
1789
1790 KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP,
1791 ("wrong opmode %u", vap->iv_opmode));
1792 bestchan = ap_pick_channel(ss, 0);
1793 if (bestchan == NULL) {
1794 /* no suitable channel, should not happen */
1795 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1796 "%s: no suitable channel! (should not happen)\n", __func__);
1797 /* XXX print something? */
1798 return 0; /* restart scan */
1799 }
1800 /*
1801 * If this is a dynamic turbo channel, start with the unboosted one.
1802 */
1803 if (IEEE80211_IS_CHAN_TURBO(bestchan)) {
1804 bestchan = ieee80211_find_channel(ic, bestchan->ic_freq,
1805 bestchan->ic_flags & ~IEEE80211_CHAN_TURBO);
1806 if (bestchan == NULL) {
1807 /* should never happen ?? */
1808 return 0;
1809 }
1810 }
1811 ap_reset_promisc(ic);
1812 if (ss->ss_flags & (IEEE80211_SCAN_NOPICK | IEEE80211_SCAN_NOJOIN)) {
1813 /*
1814 * Manual/background scan, don't select+join the
1815 * bss, just return. The scanning framework will
1816 * handle notification that this has completed.
1817 */
1818 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1819 return 1;
1820 }
1821 ieee80211_create_ibss(vap,
1822 ieee80211_ht_adjust_channel(ic, bestchan, vap->iv_flags_ht));
1823 return 1;
1824 }
1825
1826 static const struct ieee80211_scanner ap_default = {
1827 .scan_name = "default",
1828 .scan_attach = sta_attach,
1829 .scan_detach = sta_detach,
1830 .scan_start = ap_start,
1831 .scan_restart = sta_restart,
1832 .scan_cancel = ap_cancel,
1833 .scan_end = ap_end,
1834 .scan_flush = sta_flush,
1835 .scan_pickchan = ap_pick_channel,
1836 .scan_add = sta_add,
1837 .scan_age = adhoc_age,
1838 .scan_iterate = sta_iterate,
1839 .scan_assoc_success = sta_assoc_success,
1840 .scan_assoc_fail = sta_assoc_fail,
1841 };
1842 IEEE80211_SCANNER_ALG(ap, IEEE80211_M_HOSTAP, ap_default);
1843
1844 #ifdef IEEE80211_SUPPORT_MESH
1845 /*
1846 * Pick an mbss network to join or find a channel
1847 * to use to start an mbss network.
1848 */
1849 static int
1850 mesh_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1851 {
1852 struct sta_table *st = ss->ss_priv;
1853 struct ieee80211_mesh_state *ms = vap->iv_mesh;
1854 struct sta_entry *selbs;
1855 struct ieee80211_channel *chan;
1856
1857 KASSERT(vap->iv_opmode == IEEE80211_M_MBSS,
1858 ("wrong opmode %u", vap->iv_opmode));
1859
1860 if (st->st_newscan) {
1861 sta_update_notseen(st);
1862 st->st_newscan = 0;
1863 }
1864 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1865 /*
1866 * Manual/background scan, don't select+join the
1867 * bss, just return. The scanning framework will
1868 * handle notification that this has completed.
1869 */
1870 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1871 return 1;
1872 }
1873 /*
1874 * Automatic sequencing; look for a candidate and
1875 * if found join the network.
1876 */
1877 /* NB: unlocked read should be ok */
1878 if (TAILQ_FIRST(&st->st_entry) == NULL) {
1879 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1880 "%s: no scan candidate\n", __func__);
1881 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1882 return 0;
1883 notfound:
1884 if (ms->ms_idlen != 0) {
1885 /*
1886 * No existing mbss network to join and we have
1887 * a meshid; start one up. If no channel was
1888 * specified, try to select a channel.
1889 */
1890 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC ||
1891 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
1892 struct ieee80211com *ic = vap->iv_ic;
1893
1894 chan = adhoc_pick_channel(ss, 0);
1895 if (chan != NULL)
1896 chan = ieee80211_ht_adjust_channel(ic,
1897 chan, vap->iv_flags_ht);
1898 } else
1899 chan = vap->iv_des_chan;
1900 if (chan != NULL) {
1901 ieee80211_create_ibss(vap, chan);
1902 return 1;
1903 }
1904 }
1905 /*
1906 * If nothing suitable was found decrement
1907 * the failure counts so entries will be
1908 * reconsidered the next time around. We
1909 * really want to do this only for sta's
1910 * where we've previously had some success.
1911 */
1912 sta_dec_fails(st);
1913 st->st_newscan = 1;
1914 return 0; /* restart scan */
1915 }
1916 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1917 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1918 return (selbs != NULL);
1919 if (selbs == NULL)
1920 goto notfound;
1921 chan = selbs->base.se_chan;
1922 if (selbs->se_flags & STA_DEMOTE11B)
1923 chan = demote11b(vap, chan);
1924 if (!ieee80211_sta_join(vap, chan, &selbs->base))
1925 goto notfound;
1926 return 1; /* terminate scan */
1927 }
1928
1929 static const struct ieee80211_scanner mesh_default = {
1930 .scan_name = "default",
1931 .scan_attach = sta_attach,
1932 .scan_detach = sta_detach,
1933 .scan_start = adhoc_start,
1934 .scan_restart = sta_restart,
1935 .scan_cancel = sta_cancel,
1936 .scan_end = mesh_pick_bss,
1937 .scan_flush = sta_flush,
1938 .scan_pickchan = adhoc_pick_channel,
1939 .scan_add = sta_add,
1940 .scan_age = adhoc_age,
1941 .scan_iterate = sta_iterate,
1942 .scan_assoc_fail = sta_assoc_fail,
1943 .scan_assoc_success = sta_assoc_success,
1944 };
1945 IEEE80211_SCANNER_ALG(mesh, IEEE80211_M_MBSS, mesh_default);
1946 #endif /* IEEE80211_SUPPORT_MESH */
Cache object: fea3ac2e4d08bb2090dfe5fbf6c67fdc
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