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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: head/sys/net80211/ieee80211_scan_sta.c 186904 2009-01-08 17:12:47Z sam $");
27__FBSDID("$FreeBSD: head/sys/net80211/ieee80211_scan_sta.c 187991 2009-02-01 22:24:08Z 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
52#include <net/bpf.h>
53
54/*
55 * Parameters for managing cache entries:
56 *
57 * o a station with STA_FAILS_MAX failures is not considered
58 * when picking a candidate
59 * o a station that hasn't had an update in STA_PURGE_SCANS
60 * (background) scans is discarded
61 * o after STA_FAILS_AGE seconds we clear the failure count
62 */
63#define STA_FAILS_MAX 2 /* assoc failures before ignored */
64#define STA_FAILS_AGE (2*60) /* time before clearing fails (secs) */
65#define STA_PURGE_SCANS 2 /* age for purging entries (scans) */
66
67/* XXX tunable */
68#define STA_RSSI_MIN 8 /* min acceptable rssi */
69#define STA_RSSI_MAX 40 /* max rssi for comparison */
70
71struct sta_entry {
72 struct ieee80211_scan_entry base;
73 TAILQ_ENTRY(sta_entry) se_list;
74 LIST_ENTRY(sta_entry) se_hash;
75 uint8_t se_fails; /* failure to associate count */
76 uint8_t se_seen; /* seen during current scan */
77 uint8_t se_notseen; /* not seen in previous scans */
78 uint8_t se_flags;
79#define STA_DEMOTE11B 0x01 /* match w/ demoted 11b chan */
80 uint32_t se_avgrssi; /* LPF rssi state */
81 unsigned long se_lastupdate; /* time of last update */
82 unsigned long se_lastfail; /* time of last failure */
83 unsigned long se_lastassoc; /* time of last association */
84 u_int se_scangen; /* iterator scan gen# */
85 u_int se_countrygen; /* gen# of last cc notify */
86};
87
88#define STA_HASHSIZE 32
89/* simple hash is enough for variation of macaddr */
90#define STA_HASH(addr) \
91 (((const uint8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % STA_HASHSIZE)
92
93#define MAX_IEEE_CHAN 256 /* max acceptable IEEE chan # */
94CTASSERT(MAX_IEEE_CHAN >= 256);
95
96struct sta_table {
97 struct mtx st_lock; /* on scan table */
98 TAILQ_HEAD(, sta_entry) st_entry; /* all entries */
99 LIST_HEAD(, sta_entry) st_hash[STA_HASHSIZE];
100 struct mtx st_scanlock; /* on st_scaniter */
101 u_int st_scaniter; /* gen# for iterator */
102 u_int st_scangen; /* scan generation # */
103 int st_newscan;
104 /* ap-related state */
105 int st_maxrssi[MAX_IEEE_CHAN];
106};
107
108static void sta_flush_table(struct sta_table *);
109/*
110 * match_bss returns a bitmask describing if an entry is suitable
111 * for use. If non-zero the entry was deemed not suitable and it's
112 * contents explains why. The following flags are or'd to to this
113 * mask and can be used to figure out why the entry was rejected.
114 */
115#define MATCH_CHANNEL 0x0001 /* channel mismatch */
116#define MATCH_CAPINFO 0x0002 /* capabilities mismatch, e.g. no ess */
117#define MATCH_PRIVACY 0x0004 /* privacy mismatch */
118#define MATCH_RATE 0x0008 /* rate set mismatch */
119#define MATCH_SSID 0x0010 /* ssid mismatch */
120#define MATCH_BSSID 0x0020 /* bssid mismatch */
121#define MATCH_FAILS 0x0040 /* too many failed auth attempts */
122#define MATCH_NOTSEEN 0x0080 /* not seen in recent scans */
123#define MATCH_RSSI 0x0100 /* rssi deemed too low to use */
124#define MATCH_CC 0x0200 /* country code mismatch */
125#define MATCH_TDMA_NOIE 0x0400 /* no TDMA ie */
126#define MATCH_TDMA_NOTMASTER 0x0800 /* not TDMA master */
127#define MATCH_TDMA_NOSLOT 0x1000 /* all TDMA slots occupied */
128#define MATCH_TDMA_LOCAL 0x2000 /* local address */
129static int match_bss(struct ieee80211vap *,
130 const struct ieee80211_scan_state *, struct sta_entry *, int);
131static void adhoc_age(struct ieee80211_scan_state *);
132
133static __inline int
134isocmp(const uint8_t cc1[], const uint8_t cc2[])
135{
136 return (cc1[0] == cc2[0] && cc1[1] == cc2[1]);
137}
138
139/* number of references from net80211 layer */
140static int nrefs = 0;
141
142/*
143 * Attach prior to any scanning work.
144 */
145static int
146sta_attach(struct ieee80211_scan_state *ss)
147{
148 struct sta_table *st;
149
150 st = (struct sta_table *) malloc(sizeof(struct sta_table),
151 M_80211_SCAN, M_NOWAIT | M_ZERO);
152 if (st == NULL)
153 return 0;
154 mtx_init(&st->st_lock, "scantable", "802.11 scan table", MTX_DEF);
155 mtx_init(&st->st_scanlock, "scangen", "802.11 scangen", MTX_DEF);
156 TAILQ_INIT(&st->st_entry);
157 ss->ss_priv = st;
158 nrefs++; /* NB: we assume caller locking */
159 return 1;
160}
161
162/*
163 * Cleanup any private state.
164 */
165static int
166sta_detach(struct ieee80211_scan_state *ss)
167{
168 struct sta_table *st = ss->ss_priv;
169
170 if (st != NULL) {
171 sta_flush_table(st);
172 mtx_destroy(&st->st_lock);
173 mtx_destroy(&st->st_scanlock);
174 free(st, M_80211_SCAN);
175 KASSERT(nrefs > 0, ("imbalanced attach/detach"));
176 nrefs--; /* NB: we assume caller locking */
177 }
178 return 1;
179}
180
181/*
182 * Flush all per-scan state.
183 */
184static int
185sta_flush(struct ieee80211_scan_state *ss)
186{
187 struct sta_table *st = ss->ss_priv;
188
189 mtx_lock(&st->st_lock);
190 sta_flush_table(st);
191 mtx_unlock(&st->st_lock);
192 ss->ss_last = 0;
193 return 0;
194}
195
196/*
197 * Flush all entries in the scan cache.
198 */
199static void
200sta_flush_table(struct sta_table *st)
201{
202 struct sta_entry *se, *next;
203
204 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) {
205 TAILQ_REMOVE(&st->st_entry, se, se_list);
206 LIST_REMOVE(se, se_hash);
207 ieee80211_ies_cleanup(&se->base.se_ies);
208 free(se, M_80211_SCAN);
209 }
210 memset(st->st_maxrssi, 0, sizeof(st->st_maxrssi));
211}
212
213/*
214 * Process a beacon or probe response frame; create an
215 * entry in the scan cache or update any previous entry.
216 */
217static int
218sta_add(struct ieee80211_scan_state *ss,
219 const struct ieee80211_scanparams *sp,
220 const struct ieee80211_frame *wh,
221 int subtype, int rssi, int noise, int rstamp)
222{
223#define ISPROBE(_st) ((_st) == IEEE80211_FC0_SUBTYPE_PROBE_RESP)
224#define PICK1ST(_ss) \
225 ((ss->ss_flags & (IEEE80211_SCAN_PICK1ST | IEEE80211_SCAN_GOTPICK)) == \
226 IEEE80211_SCAN_PICK1ST)
227 struct sta_table *st = ss->ss_priv;
228 const uint8_t *macaddr = wh->i_addr2;
229 struct ieee80211vap *vap = ss->ss_vap;
230 struct ieee80211com *ic = vap->iv_ic;
231 struct sta_entry *se;
232 struct ieee80211_scan_entry *ise;
233 int hash;
234
235 hash = STA_HASH(macaddr);
236
237 mtx_lock(&st->st_lock);
238 LIST_FOREACH(se, &st->st_hash[hash], se_hash)
239 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr))
240 goto found;
241 se = (struct sta_entry *) malloc(sizeof(struct sta_entry),
242 M_80211_SCAN, M_NOWAIT | M_ZERO);
243 if (se == NULL) {
244 mtx_unlock(&st->st_lock);
245 return 0;
246 }
247 se->se_scangen = st->st_scaniter-1;
248 se->se_avgrssi = IEEE80211_RSSI_DUMMY_MARKER;
249 IEEE80211_ADDR_COPY(se->base.se_macaddr, macaddr);
250 TAILQ_INSERT_TAIL(&st->st_entry, se, se_list);
251 LIST_INSERT_HEAD(&st->st_hash[hash], se, se_hash);
252found:
253 ise = &se->base;
254 /* XXX ap beaconing multiple ssid w/ same bssid */
255 if (sp->ssid[1] != 0 &&
256 (ISPROBE(subtype) || ise->se_ssid[1] == 0))
257 memcpy(ise->se_ssid, sp->ssid, 2+sp->ssid[1]);
258 KASSERT(sp->rates[1] <= IEEE80211_RATE_MAXSIZE,
259 ("rate set too large: %u", sp->rates[1]));
260 memcpy(ise->se_rates, sp->rates, 2+sp->rates[1]);
261 if (sp->xrates != NULL) {
262 /* XXX validate xrates[1] */
263 KASSERT(sp->xrates[1] <= IEEE80211_RATE_MAXSIZE,
264 ("xrate set too large: %u", sp->xrates[1]));
265 memcpy(ise->se_xrates, sp->xrates, 2+sp->xrates[1]);
266 } else
267 ise->se_xrates[1] = 0;
268 IEEE80211_ADDR_COPY(ise->se_bssid, wh->i_addr3);
269 if ((sp->status & IEEE80211_BPARSE_OFFCHAN) == 0) {
270 /*
271 * Record rssi data using extended precision LPF filter.
272 *
273 * NB: use only on-channel data to insure we get a good
274 * estimate of the signal we'll see when associated.
275 */
276 IEEE80211_RSSI_LPF(se->se_avgrssi, rssi);
277 ise->se_rssi = IEEE80211_RSSI_GET(se->se_avgrssi);
278 ise->se_noise = noise;
279 }
280 ise->se_rstamp = rstamp;
281 memcpy(ise->se_tstamp.data, sp->tstamp, sizeof(ise->se_tstamp));
282 ise->se_intval = sp->bintval;
283 ise->se_capinfo = sp->capinfo;
284 /*
285 * Beware of overriding se_chan for frames seen
286 * off-channel; this can cause us to attempt an
287 * association on the wrong channel.
288 */
289 if (sp->status & IEEE80211_BPARSE_OFFCHAN) {
290 struct ieee80211_channel *c;
291 /*
292 * Off-channel, locate the home/bss channel for the sta
293 * using the value broadcast in the DSPARMS ie. We know
294 * sp->chan has this value because it's used to calculate
295 * IEEE80211_BPARSE_OFFCHAN.
296 */
297 c = ieee80211_find_channel_byieee(ic, sp->chan,
298 ic->ic_curchan->ic_flags);
299 if (c != NULL) {
300 ise->se_chan = c;
301 } else if (ise->se_chan == NULL) {
302 /* should not happen, pick something */
303 ise->se_chan = ic->ic_curchan;
304 }
305 } else
306 ise->se_chan = ic->ic_curchan;
307 ise->se_fhdwell = sp->fhdwell;
308 ise->se_fhindex = sp->fhindex;
309 ise->se_erp = sp->erp;
310 ise->se_timoff = sp->timoff;
311 if (sp->tim != NULL) {
312 const struct ieee80211_tim_ie *tim =
313 (const struct ieee80211_tim_ie *) sp->tim;
314 ise->se_dtimperiod = tim->tim_period;
315 }
316 if (sp->country != NULL) {
317 const struct ieee80211_country_ie *cie =
318 (const struct ieee80211_country_ie *) sp->country;
319 /*
320 * If 11d is enabled and we're attempting to join a bss
321 * that advertises it's country code then compare our
322 * current settings to what we fetched from the country ie.
323 * If our country code is unspecified or different then
324 * dispatch an event to user space that identifies the
325 * country code so our regdomain config can be changed.
326 */
327 /* XXX only for STA mode? */
328 if ((IEEE80211_IS_CHAN_11D(ise->se_chan) ||
329 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) &&
330 (ic->ic_regdomain.country == CTRY_DEFAULT ||
331 !isocmp(cie->cc, ic->ic_regdomain.isocc))) {
332 /* only issue one notify event per scan */
333 if (se->se_countrygen != st->st_scangen) {
334 ieee80211_notify_country(vap, ise->se_bssid,
335 cie->cc);
336 se->se_countrygen = st->st_scangen;
337 }
338 }
339 ise->se_cc[0] = cie->cc[0];
340 ise->se_cc[1] = cie->cc[1];
341 }
342 /* NB: no need to setup ie ptrs; they are not (currently) used */
343 (void) ieee80211_ies_init(&ise->se_ies, sp->ies, sp->ies_len);
344
345 /* clear failure count after STA_FAIL_AGE passes */
346 if (se->se_fails && (ticks - se->se_lastfail) > STA_FAILS_AGE*hz) {
347 se->se_fails = 0;
348 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, macaddr,
349 "%s: fails %u", __func__, se->se_fails);
350 }
351
352 se->se_lastupdate = ticks; /* update time */
353 se->se_seen = 1;
354 se->se_notseen = 0;
355
356 KASSERT(sizeof(sp->bchan) == 1, ("bchan size"));
357 if (rssi > st->st_maxrssi[sp->bchan])
358 st->st_maxrssi[sp->bchan] = rssi;
359
360 mtx_unlock(&st->st_lock);
361
362 /*
363 * If looking for a quick choice and nothing's
364 * been found check here.
365 */
366 if (PICK1ST(ss) && match_bss(vap, ss, se, IEEE80211_MSG_SCAN) == 0)
367 ss->ss_flags |= IEEE80211_SCAN_GOTPICK;
368
369 return 1;
370#undef PICK1ST
371#undef ISPROBE
372}
373
374/*
375 * Check if a channel is excluded by user request.
376 */
377static int
378isexcluded(struct ieee80211vap *vap, const struct ieee80211_channel *c)
379{
380 return (isclr(vap->iv_ic->ic_chan_active, c->ic_ieee) ||
381 (vap->iv_des_chan != IEEE80211_CHAN_ANYC &&
382 c->ic_freq != vap->iv_des_chan->ic_freq));
383}
384
385static struct ieee80211_channel *
386find11gchannel(struct ieee80211com *ic, int i, int freq)
387{
388 struct ieee80211_channel *c;
389 int j;
390
391 /*
392 * The normal ordering in the channel list is b channel
393 * immediately followed by g so optimize the search for
394 * this. We'll still do a full search just in case.
395 */
396 for (j = i+1; j < ic->ic_nchans; j++) {
397 c = &ic->ic_channels[j];
398 if (c->ic_freq == freq && IEEE80211_IS_CHAN_ANYG(c))
398 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c))
399 return c;
400 }
401 for (j = 0; j < i; j++) {
402 c = &ic->ic_channels[j];
403 if (c->ic_freq == freq && IEEE80211_IS_CHAN_ANYG(c))
403 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c))
404 return c;
405 }
406 return NULL;
407}
408static const u_int chanflags[IEEE80211_MODE_MAX] = {
409 IEEE80211_CHAN_B, /* IEEE80211_MODE_AUTO */
410 IEEE80211_CHAN_A, /* IEEE80211_MODE_11A */
411 IEEE80211_CHAN_B, /* IEEE80211_MODE_11B */
412 IEEE80211_CHAN_G, /* IEEE80211_MODE_11G */
413 IEEE80211_CHAN_FHSS, /* IEEE80211_MODE_FH */
414 IEEE80211_CHAN_A, /* IEEE80211_MODE_TURBO_A (check base channel)*/
415 IEEE80211_CHAN_G, /* IEEE80211_MODE_TURBO_G */
416 IEEE80211_CHAN_ST, /* IEEE80211_MODE_STURBO_A */
417 IEEE80211_CHAN_A, /* IEEE80211_MODE_11NA (check legacy) */
418 IEEE80211_CHAN_G, /* IEEE80211_MODE_11NG (check legacy) */
419};
420
421static void
422add_channels(struct ieee80211vap *vap,
423 struct ieee80211_scan_state *ss,
424 enum ieee80211_phymode mode, const uint16_t freq[], int nfreq)
425{
426#define N(a) (sizeof(a) / sizeof(a[0]))
427 struct ieee80211com *ic = vap->iv_ic;
428 struct ieee80211_channel *c, *cg;
429 u_int modeflags;
430 int i;
431
432 KASSERT(mode < N(chanflags), ("Unexpected mode %u", mode));
433 modeflags = chanflags[mode];
434 for (i = 0; i < nfreq; i++) {
435 if (ss->ss_last >= IEEE80211_SCAN_MAX)
436 break;
437
438 c = ieee80211_find_channel(ic, freq[i], modeflags);
439 if (c == NULL || isexcluded(vap, c))
440 continue;
441 if (mode == IEEE80211_MODE_AUTO) {
442 /*
443 * XXX special-case 11b/g channels so we select
444 * the g channel if both are present.
445 */
446 if (IEEE80211_IS_CHAN_B(c) &&
447 (cg = find11gchannel(ic, i, c->ic_freq)) != NULL)
448 c = cg;
449 }
450 ss->ss_chans[ss->ss_last++] = c;
451 }
452#undef N
453}
454
455struct scanlist {
456 uint16_t mode;
457 uint16_t count;
458 const uint16_t *list;
459};
460
461static int
462checktable(const struct scanlist *scan, const struct ieee80211_channel *c)
463{
464 int i;
465
466 for (; scan->list != NULL; scan++) {
467 for (i = 0; i < scan->count; i++)
468 if (scan->list[i] == c->ic_freq)
469 return 1;
470 }
471 return 0;
472}
473
474static void
475sweepchannels(struct ieee80211_scan_state *ss, struct ieee80211vap *vap,
476 const struct scanlist table[])
477{
478 struct ieee80211com *ic = vap->iv_ic;
479 struct ieee80211_channel *c;
480 int i;
481
482 for (i = 0; i < ic->ic_nchans; i++) {
483 if (ss->ss_last >= IEEE80211_SCAN_MAX)
484 break;
485
486 c = &ic->ic_channels[i];
487 /*
488 * Ignore dynamic turbo channels; we scan them
489 * in normal mode (i.e. not boosted). Likewise
490 * for HT channels, they get scanned using
491 * legacy rates.
492 */
493 if (IEEE80211_IS_CHAN_DTURBO(c) || IEEE80211_IS_CHAN_HT(c))
494 continue;
495
496 /*
497 * If a desired mode was specified, scan only
498 * channels that satisfy that constraint.
499 */
500 if (vap->iv_des_mode != IEEE80211_MODE_AUTO &&
501 vap->iv_des_mode != ieee80211_chan2mode(c))
502 continue;
503
504 /*
505 * Skip channels excluded by user request.
506 */
507 if (isexcluded(vap, c))
508 continue;
509
510 /*
511 * Add the channel unless it is listed in the
512 * fixed scan order tables. This insures we
513 * don't sweep back in channels we filtered out
514 * above.
515 */
516 if (checktable(table, c))
517 continue;
518
519 /* Add channel to scanning list. */
520 ss->ss_chans[ss->ss_last++] = c;
521 }
522}
523
524static void
525makescanlist(struct ieee80211_scan_state *ss, struct ieee80211vap *vap,
526 const struct scanlist table[])
527{
528 const struct scanlist *scan;
529 enum ieee80211_phymode mode;
530
531 ss->ss_last = 0;
532 /*
533 * Use the table of ordered channels to construct the list
534 * of channels for scanning. Any channels in the ordered
535 * list not in the master list will be discarded.
536 */
537 for (scan = table; scan->list != NULL; scan++) {
538 mode = scan->mode;
539 if (vap->iv_des_mode != IEEE80211_MODE_AUTO) {
540 /*
541 * If a desired mode was specified, scan only
542 * channels that satisfy that constraint.
543 */
544 if (vap->iv_des_mode != mode) {
545 /*
546 * The scan table marks 2.4Ghz channels as b
547 * so if the desired mode is 11g, then use
548 * the 11b channel list but upgrade the mode.
549 */
550 if (vap->iv_des_mode != IEEE80211_MODE_11G ||
551 mode != IEEE80211_MODE_11B)
552 continue;
553 mode = IEEE80211_MODE_11G; /* upgrade */
554 }
555 } else {
556 /*
557 * This lets add_channels upgrade an 11b channel
558 * to 11g if available.
559 */
560 if (mode == IEEE80211_MODE_11B)
561 mode = IEEE80211_MODE_AUTO;
562 }
563#ifdef IEEE80211_F_XR
564 /* XR does not operate on turbo channels */
565 if ((vap->iv_flags & IEEE80211_F_XR) &&
566 (mode == IEEE80211_MODE_TURBO_A ||
567 mode == IEEE80211_MODE_TURBO_G ||
568 mode == IEEE80211_MODE_STURBO_A))
569 continue;
570#endif
571 /*
572 * Add the list of the channels; any that are not
573 * in the master channel list will be discarded.
574 */
575 add_channels(vap, ss, mode, scan->list, scan->count);
576 }
577
578 /*
579 * Add the channels from the ic that are not present
580 * in the table.
581 */
582 sweepchannels(ss, vap, table);
583}
584
585static const uint16_t rcl1[] = /* 8 FCC channel: 52, 56, 60, 64, 36, 40, 44, 48 */
586{ 5260, 5280, 5300, 5320, 5180, 5200, 5220, 5240 };
587static const uint16_t rcl2[] = /* 4 MKK channels: 34, 38, 42, 46 */
588{ 5170, 5190, 5210, 5230 };
589static const uint16_t rcl3[] = /* 2.4Ghz ch: 1,6,11,7,13 */
590{ 2412, 2437, 2462, 2442, 2472 };
591static const uint16_t rcl4[] = /* 5 FCC channel: 149, 153, 161, 165 */
592{ 5745, 5765, 5785, 5805, 5825 };
593static const uint16_t rcl7[] = /* 11 ETSI channel: 100,104,108,112,116,120,124,128,132,136,140 */
594{ 5500, 5520, 5540, 5560, 5580, 5600, 5620, 5640, 5660, 5680, 5700 };
595static const uint16_t rcl8[] = /* 2.4Ghz ch: 2,3,4,5,8,9,10,12 */
596{ 2417, 2422, 2427, 2432, 2447, 2452, 2457, 2467 };
597static const uint16_t rcl9[] = /* 2.4Ghz ch: 14 */
598{ 2484 };
599static const uint16_t rcl10[] = /* Added Korean channels 2312-2372 */
600{ 2312, 2317, 2322, 2327, 2332, 2337, 2342, 2347, 2352, 2357, 2362, 2367, 2372 };
601static const uint16_t rcl11[] = /* Added Japan channels in 4.9/5.0 spectrum */
602{ 5040, 5060, 5080, 4920, 4940, 4960, 4980 };
603#ifdef ATH_TURBO_SCAN
604static const uint16_t rcl5[] = /* 3 static turbo channels */
605{ 5210, 5250, 5290 };
606static const uint16_t rcl6[] = /* 2 static turbo channels */
607{ 5760, 5800 };
608static const uint16_t rcl6x[] = /* 4 FCC3 turbo channels */
609{ 5540, 5580, 5620, 5660 };
610static const uint16_t rcl12[] = /* 2.4Ghz Turbo channel 6 */
611{ 2437 };
612static const uint16_t rcl13[] = /* dynamic Turbo channels */
613{ 5200, 5240, 5280, 5765, 5805 };
614#endif /* ATH_TURBO_SCAN */
615
616#define X(a) .count = sizeof(a)/sizeof(a[0]), .list = a
617
618static const struct scanlist staScanTable[] = {
619 { IEEE80211_MODE_11B, X(rcl3) },
620 { IEEE80211_MODE_11A, X(rcl1) },
621 { IEEE80211_MODE_11A, X(rcl2) },
622 { IEEE80211_MODE_11B, X(rcl8) },
623 { IEEE80211_MODE_11B, X(rcl9) },
624 { IEEE80211_MODE_11A, X(rcl4) },
625#ifdef ATH_TURBO_SCAN
626 { IEEE80211_MODE_STURBO_A, X(rcl5) },
627 { IEEE80211_MODE_STURBO_A, X(rcl6) },
628 { IEEE80211_MODE_TURBO_A, X(rcl6x) },
629 { IEEE80211_MODE_TURBO_A, X(rcl13) },
630#endif /* ATH_TURBO_SCAN */
631 { IEEE80211_MODE_11A, X(rcl7) },
632 { IEEE80211_MODE_11B, X(rcl10) },
633 { IEEE80211_MODE_11A, X(rcl11) },
634#ifdef ATH_TURBO_SCAN
635 { IEEE80211_MODE_TURBO_G, X(rcl12) },
636#endif /* ATH_TURBO_SCAN */
637 { .list = NULL }
638};
639
640/*
641 * Start a station-mode scan by populating the channel list.
642 */
643static int
644sta_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
645{
646 struct sta_table *st = ss->ss_priv;
647
648 makescanlist(ss, vap, staScanTable);
649
650 if (ss->ss_mindwell == 0)
651 ss->ss_mindwell = msecs_to_ticks(20); /* 20ms */
652 if (ss->ss_maxdwell == 0)
653 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
654
655 st->st_scangen++;
656 st->st_newscan = 1;
657
658 return 0;
659}
660
661/*
662 * Restart a scan, typically a bg scan but can
663 * also be a fg scan that came up empty.
664 */
665static int
666sta_restart(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
667{
668 struct sta_table *st = ss->ss_priv;
669
670 st->st_newscan = 1;
671 return 0;
672}
673
674/*
675 * Cancel an ongoing scan.
676 */
677static int
678sta_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
679{
680 return 0;
681}
682
683/* unalligned little endian access */
684#define LE_READ_2(p) \
685 ((uint16_t) \
686 ((((const uint8_t *)(p))[0] ) | \
687 (((const uint8_t *)(p))[1] << 8)))
688
689/*
690 * Demote any supplied 11g channel to 11b. There should
691 * always be an 11b channel but we check anyway...
692 */
693static struct ieee80211_channel *
694demote11b(struct ieee80211vap *vap, struct ieee80211_channel *chan)
695{
696 struct ieee80211_channel *c;
697
698 if (IEEE80211_IS_CHAN_ANYG(chan) &&
699 vap->iv_des_mode == IEEE80211_MODE_AUTO) {
700 c = ieee80211_find_channel(vap->iv_ic, chan->ic_freq,
701 (chan->ic_flags &~ (IEEE80211_CHAN_PUREG | IEEE80211_CHAN_G)) |
702 IEEE80211_CHAN_B);
703 if (c != NULL)
704 chan = c;
705 }
706 return chan;
707}
708
709static int
710maxrate(const struct ieee80211_scan_entry *se)
711{
712 const struct ieee80211_ie_htcap *htcap =
713 (const struct ieee80211_ie_htcap *) se->se_ies.htcap_ie;
714 int rmax, r, i;
715 uint16_t caps;
716
717 rmax = 0;
718 if (htcap != NULL) {
719 /*
720 * HT station; inspect supported MCS and then adjust
721 * rate by channel width. Could also include short GI
722 * in this if we want to be extra accurate.
723 */
724 /* XXX assumes MCS15 is max */
725 for (i = 15; i >= 0 && isclr(htcap->hc_mcsset, i); i--)
726 ;
727 if (i >= 0) {
728 caps = LE_READ_2(&htcap->hc_cap);
729 /* XXX short/long GI */
730 if (caps & IEEE80211_HTCAP_CHWIDTH40)
731 rmax = ieee80211_htrates[i].ht40_rate_400ns;
732 else
733 rmax = ieee80211_htrates[i].ht40_rate_800ns;
734 }
735 }
736 for (i = 0; i < se->se_rates[1]; i++) {
737 r = se->se_rates[2+i] & IEEE80211_RATE_VAL;
738 if (r > rmax)
739 rmax = r;
740 }
741 for (i = 0; i < se->se_xrates[1]; i++) {
742 r = se->se_xrates[2+i] & IEEE80211_RATE_VAL;
743 if (r > rmax)
744 rmax = r;
745 }
746 return rmax;
747}
748
749/*
750 * Compare the capabilities of two entries and decide which is
751 * more desirable (return >0 if a is considered better). Note
752 * that we assume compatibility/usability has already been checked
753 * so we don't need to (e.g. validate whether privacy is supported).
754 * Used to select the best scan candidate for association in a BSS.
755 */
756static int
757sta_compare(const struct sta_entry *a, const struct sta_entry *b)
758{
759#define PREFER(_a,_b,_what) do { \
760 if (((_a) ^ (_b)) & (_what)) \
761 return ((_a) & (_what)) ? 1 : -1; \
762} while (0)
763 int maxa, maxb;
764 int8_t rssia, rssib;
765 int weight;
766
767 /* privacy support */
768 PREFER(a->base.se_capinfo, b->base.se_capinfo,
769 IEEE80211_CAPINFO_PRIVACY);
770
771 /* compare count of previous failures */
772 weight = b->se_fails - a->se_fails;
773 if (abs(weight) > 1)
774 return weight;
775
776 /*
777 * Compare rssi. If the two are considered equivalent
778 * then fallback to other criteria. We threshold the
779 * comparisons to avoid selecting an ap purely by rssi
780 * when both values may be good but one ap is otherwise
781 * more desirable (e.g. an 11b-only ap with stronger
782 * signal than an 11g ap).
783 */
784 rssia = MIN(a->base.se_rssi, STA_RSSI_MAX);
785 rssib = MIN(b->base.se_rssi, STA_RSSI_MAX);
786 if (abs(rssib - rssia) < 5) {
787 /* best/max rate preferred if signal level close enough XXX */
788 maxa = maxrate(&a->base);
789 maxb = maxrate(&b->base);
790 if (maxa != maxb)
791 return maxa - maxb;
792 /* XXX use freq for channel preference */
793 /* for now just prefer 5Ghz band to all other bands */
794 PREFER(IEEE80211_IS_CHAN_5GHZ(a->base.se_chan),
795 IEEE80211_IS_CHAN_5GHZ(b->base.se_chan), 1);
796 }
797 /* all things being equal, use signal level */
798 return a->base.se_rssi - b->base.se_rssi;
799#undef PREFER
800}
801
802/*
803 * Check rate set suitability and return the best supported rate.
804 * XXX inspect MCS for HT
805 */
806static int
807check_rate(struct ieee80211vap *vap, const struct ieee80211_channel *chan,
808 const struct ieee80211_scan_entry *se)
809{
810#define RV(v) ((v) & IEEE80211_RATE_VAL)
811 const struct ieee80211_rateset *srs;
812 int i, j, nrs, r, okrate, badrate, fixedrate, ucastrate;
813 const uint8_t *rs;
814
815 okrate = badrate = 0;
816
817 srs = ieee80211_get_suprates(vap->iv_ic, chan);
818 nrs = se->se_rates[1];
819 rs = se->se_rates+2;
820 /* XXX MCS */
821 ucastrate = vap->iv_txparms[ieee80211_chan2mode(chan)].ucastrate;
822 fixedrate = IEEE80211_FIXED_RATE_NONE;
823again:
824 for (i = 0; i < nrs; i++) {
825 r = RV(rs[i]);
826 badrate = r;
827 /*
828 * Check any fixed rate is included.
829 */
830 if (r == ucastrate)
831 fixedrate = r;
832 /*
833 * Check against our supported rates.
834 */
835 for (j = 0; j < srs->rs_nrates; j++)
836 if (r == RV(srs->rs_rates[j])) {
837 if (r > okrate) /* NB: track max */
838 okrate = r;
839 break;
840 }
841
842 if (j == srs->rs_nrates && (rs[i] & IEEE80211_RATE_BASIC)) {
843 /*
844 * Don't try joining a BSS, if we don't support
845 * one of its basic rates.
846 */
847 okrate = 0;
848 goto back;
849 }
850 }
851 if (rs == se->se_rates+2) {
852 /* scan xrates too; sort of an algol68-style for loop */
853 nrs = se->se_xrates[1];
854 rs = se->se_xrates+2;
855 goto again;
856 }
857
858back:
859 if (okrate == 0 || ucastrate != fixedrate)
860 return badrate | IEEE80211_RATE_BASIC;
861 else
862 return RV(okrate);
863#undef RV
864}
865
866static int
867match_ssid(const uint8_t *ie,
868 int nssid, const struct ieee80211_scan_ssid ssids[])
869{
870 int i;
871
872 for (i = 0; i < nssid; i++) {
873 if (ie[1] == ssids[i].len &&
874 memcmp(ie+2, ssids[i].ssid, ie[1]) == 0)
875 return 1;
876 }
877 return 0;
878}
879
880#ifdef IEEE80211_SUPPORT_TDMA
881static int
882tdma_isfull(const struct ieee80211_tdma_param *tdma)
883{
884 int slot, slotcnt;
885
886 slotcnt = tdma->tdma_slotcnt;
887 for (slot = slotcnt-1; slot >= 0; slot--)
888 if (isclr(tdma->tdma_inuse, slot))
889 return 0;
890 return 1;
891}
892#endif /* IEEE80211_SUPPORT_TDMA */
893
894/*
895 * Test a scan candidate for suitability/compatibility.
896 */
897static int
898match_bss(struct ieee80211vap *vap,
899 const struct ieee80211_scan_state *ss, struct sta_entry *se0,
900 int debug)
901{
902 struct ieee80211com *ic = vap->iv_ic;
903 struct ieee80211_scan_entry *se = &se0->base;
904 uint8_t rate;
905 int fail;
906
907 fail = 0;
908 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, se->se_chan)))
909 fail |= MATCH_CHANNEL;
910 /*
911 * NB: normally the desired mode is used to construct
912 * the channel list, but it's possible for the scan
913 * cache to include entries for stations outside this
914 * list so we check the desired mode here to weed them
915 * out.
916 */
917 if (vap->iv_des_mode != IEEE80211_MODE_AUTO &&
918 (se->se_chan->ic_flags & IEEE80211_CHAN_ALLTURBO) !=
919 chanflags[vap->iv_des_mode])
920 fail |= MATCH_CHANNEL;
921 if (vap->iv_opmode == IEEE80211_M_IBSS) {
922 if ((se->se_capinfo & IEEE80211_CAPINFO_IBSS) == 0)
923 fail |= MATCH_CAPINFO;
924#ifdef IEEE80211_SUPPORT_TDMA
925 } else if (vap->iv_opmode == IEEE80211_M_AHDEMO) {
926 /*
927 * Adhoc demo network setup shouldn't really be scanning
928 * but just in case skip stations operating in IBSS or
929 * BSS mode.
930 */
931 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS))
932 fail |= MATCH_CAPINFO;
933 /*
934 * TDMA operation cannot coexist with a normal 802.11 network;
935 * skip if IBSS or ESS capabilities are marked and require
936 * the beacon have a TDMA ie present.
937 */
938 if (vap->iv_caps & IEEE80211_C_TDMA) {
939 const struct ieee80211_tdma_param *tdma =
940 (const struct ieee80211_tdma_param *)se->se_ies.tdma_ie;
941
942 if (tdma == NULL)
943 fail |= MATCH_TDMA_NOIE;
944 else if (tdma->tdma_slot != 0)
945 fail |= MATCH_TDMA_NOTMASTER;
946 else if (tdma_isfull(tdma))
947 fail |= MATCH_TDMA_NOSLOT;
948#if 0
949 else if (ieee80211_local_address(se->se_macaddr))
950 fail |= MATCH_TDMA_LOCAL;
951#endif
952 }
953#endif /* IEEE80211_SUPPORT_TDMA */
954 } else {
955 if ((se->se_capinfo & IEEE80211_CAPINFO_ESS) == 0)
956 fail |= MATCH_CAPINFO;
957 /*
958 * If 11d is enabled and we're attempting to join a bss
959 * that advertises it's country code then compare our
960 * current settings to what we fetched from the country ie.
961 * If our country code is unspecified or different then do
962 * not attempt to join the bss. We should have already
963 * dispatched an event to user space that identifies the
964 * new country code so our regdomain config should match.
965 */
966 if ((IEEE80211_IS_CHAN_11D(se->se_chan) ||
967 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) &&
968 se->se_cc[0] != 0 &&
969 (ic->ic_regdomain.country == CTRY_DEFAULT ||
970 !isocmp(se->se_cc, ic->ic_regdomain.isocc)))
971 fail |= MATCH_CC;
972 }
973 if (vap->iv_flags & IEEE80211_F_PRIVACY) {
974 if ((se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0)
975 fail |= MATCH_PRIVACY;
976 } else {
977 /* XXX does this mean privacy is supported or required? */
978 if (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY)
979 fail |= MATCH_PRIVACY;
980 }
981 se0->se_flags &= ~STA_DEMOTE11B;
982 rate = check_rate(vap, se->se_chan, se);
983 if (rate & IEEE80211_RATE_BASIC) {
984 fail |= MATCH_RATE;
985 /*
986 * An 11b-only ap will give a rate mismatch if there is an
987 * OFDM fixed tx rate for 11g. Try downgrading the channel
988 * in the scan list to 11b and retry the rate check.
989 */
990 if (IEEE80211_IS_CHAN_ANYG(se->se_chan)) {
991 rate = check_rate(vap, demote11b(vap, se->se_chan), se);
992 if ((rate & IEEE80211_RATE_BASIC) == 0) {
993 fail &= ~MATCH_RATE;
994 se0->se_flags |= STA_DEMOTE11B;
995 }
996 }
997 } else if (rate < 2*24) {
998 /*
999 * This is an 11b-only ap. Check the desired mode in
1000 * case that needs to be honored (mode 11g filters out
1001 * 11b-only ap's). Otherwise force any 11g channel used
1002 * in scanning to be demoted.
1003 *
1004 * NB: we cheat a bit here by looking at the max rate;
1005 * we could/should check the rates.
1006 */
1007 if (!(vap->iv_des_mode == IEEE80211_MODE_AUTO ||
1008 vap->iv_des_mode == IEEE80211_MODE_11B))
1009 fail |= MATCH_RATE;
1010 else
1011 se0->se_flags |= STA_DEMOTE11B;
1012 }
1013 if (ss->ss_nssid != 0 &&
1014 !match_ssid(se->se_ssid, ss->ss_nssid, ss->ss_ssid))
1015 fail |= MATCH_SSID;
1016 if ((vap->iv_flags & IEEE80211_F_DESBSSID) &&
1017 !IEEE80211_ADDR_EQ(vap->iv_des_bssid, se->se_bssid))
1018 fail |= MATCH_BSSID;
1019 if (se0->se_fails >= STA_FAILS_MAX)
1020 fail |= MATCH_FAILS;
1021 if (se0->se_notseen >= STA_PURGE_SCANS)
1022 fail |= MATCH_NOTSEEN;
1023 if (se->se_rssi < STA_RSSI_MIN)
1024 fail |= MATCH_RSSI;
1025#ifdef IEEE80211_DEBUG
1026 if (ieee80211_msg(vap, debug)) {
1027 printf(" %c %s",
1028 fail & MATCH_FAILS ? '=' :
1029 fail & MATCH_NOTSEEN ? '^' :
1030 fail & MATCH_CC ? '$' :
1031#ifdef IEEE80211_SUPPORT_TDMA
1032 fail & MATCH_TDMA_NOIE ? '&' :
1033 fail & MATCH_TDMA_NOTMASTER ? ':' :
1034 fail & MATCH_TDMA_NOSLOT ? '@' :
1035 fail & MATCH_TDMA_LOCAL ? '#' :
1036#endif
1037 fail ? '-' : '+', ether_sprintf(se->se_macaddr));
1038 printf(" %s%c", ether_sprintf(se->se_bssid),
1039 fail & MATCH_BSSID ? '!' : ' ');
1040 printf(" %3d%c", ieee80211_chan2ieee(ic, se->se_chan),
1041 fail & MATCH_CHANNEL ? '!' : ' ');
1042 printf(" %+4d%c", se->se_rssi, fail & MATCH_RSSI ? '!' : ' ');
1043 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2,
1044 fail & MATCH_RATE ? '!' : ' ');
1045 printf(" %4s%c",
1046 (se->se_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" :
1047 (se->se_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" :
1048 "????",
1049 fail & MATCH_CAPINFO ? '!' : ' ');
1050 printf(" %3s%c ",
1051 (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) ?
1052 "wep" : "no",
1053 fail & MATCH_PRIVACY ? '!' : ' ');
1054 ieee80211_print_essid(se->se_ssid+2, se->se_ssid[1]);
1055 printf("%s\n", fail & MATCH_SSID ? "!" : "");
1056 }
1057#endif
1058 return fail;
1059}
1060
1061static void
1062sta_update_notseen(struct sta_table *st)
1063{
1064 struct sta_entry *se;
1065
1066 mtx_lock(&st->st_lock);
1067 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1068 /*
1069 * If seen the reset and don't bump the count;
1070 * otherwise bump the ``not seen'' count. Note
1071 * that this insures that stations for which we
1072 * see frames while not scanning but not during
1073 * this scan will not be penalized.
1074 */
1075 if (se->se_seen)
1076 se->se_seen = 0;
1077 else
1078 se->se_notseen++;
1079 }
1080 mtx_unlock(&st->st_lock);
1081}
1082
1083static void
1084sta_dec_fails(struct sta_table *st)
1085{
1086 struct sta_entry *se;
1087
1088 mtx_lock(&st->st_lock);
1089 TAILQ_FOREACH(se, &st->st_entry, se_list)
1090 if (se->se_fails)
1091 se->se_fails--;
1092 mtx_unlock(&st->st_lock);
1093}
1094
1095static struct sta_entry *
1096select_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, int debug)
1097{
1098 struct sta_table *st = ss->ss_priv;
1099 struct sta_entry *se, *selbs = NULL;
1100
1101 IEEE80211_DPRINTF(vap, debug, " %s\n",
1102 "macaddr bssid chan rssi rate flag wep essid");
1103 mtx_lock(&st->st_lock);
1104 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1105 ieee80211_ies_expand(&se->base.se_ies);
1106 if (match_bss(vap, ss, se, debug) == 0) {
1107 if (selbs == NULL)
1108 selbs = se;
1109 else if (sta_compare(se, selbs) > 0)
1110 selbs = se;
1111 }
1112 }
1113 mtx_unlock(&st->st_lock);
1114
1115 return selbs;
1116}
1117
1118/*
1119 * Pick an ap or ibss network to join or find a channel
1120 * to use to start an ibss network.
1121 */
1122static int
1123sta_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1124{
1125 struct sta_table *st = ss->ss_priv;
1126 struct sta_entry *selbs;
1127 struct ieee80211_channel *chan;
1128
1129 KASSERT(vap->iv_opmode == IEEE80211_M_STA,
1130 ("wrong mode %u", vap->iv_opmode));
1131
1132 if (st->st_newscan) {
1133 sta_update_notseen(st);
1134 st->st_newscan = 0;
1135 }
1136 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1137 /*
1138 * Manual/background scan, don't select+join the
1139 * bss, just return. The scanning framework will
1140 * handle notification that this has completed.
1141 */
1142 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1143 return 1;
1144 }
1145 /*
1146 * Automatic sequencing; look for a candidate and
1147 * if found join the network.
1148 */
1149 /* NB: unlocked read should be ok */
1150 if (TAILQ_FIRST(&st->st_entry) == NULL) {
1151 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1152 "%s: no scan candidate\n", __func__);
1153 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1154 return 0;
1155notfound:
1156 /*
1157 * If nothing suitable was found decrement
1158 * the failure counts so entries will be
1159 * reconsidered the next time around. We
1160 * really want to do this only for sta's
1161 * where we've previously had some success.
1162 */
1163 sta_dec_fails(st);
1164 st->st_newscan = 1;
1165 return 0; /* restart scan */
1166 }
1167 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1168 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1169 return (selbs != NULL);
1170 if (selbs == NULL)
1171 goto notfound;
1172 chan = selbs->base.se_chan;
1173 if (selbs->se_flags & STA_DEMOTE11B)
1174 chan = demote11b(vap, chan);
1175 if (!ieee80211_sta_join(vap, chan, &selbs->base))
1176 goto notfound;
1177 return 1; /* terminate scan */
1178}
1179
1180/*
1181 * Lookup an entry in the scan cache. We assume we're
1182 * called from the bottom half or such that we don't need
1183 * to block the bottom half so that it's safe to return
1184 * a reference to an entry w/o holding the lock on the table.
1185 */
1186static struct sta_entry *
1187sta_lookup(struct sta_table *st, const uint8_t macaddr[IEEE80211_ADDR_LEN])
1188{
1189 struct sta_entry *se;
1190 int hash = STA_HASH(macaddr);
1191
1192 mtx_lock(&st->st_lock);
1193 LIST_FOREACH(se, &st->st_hash[hash], se_hash)
1194 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr))
1195 break;
1196 mtx_unlock(&st->st_lock);
1197
1198 return se; /* NB: unlocked */
1199}
1200
1201static void
1202sta_roam_check(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1203{
1204 struct ieee80211com *ic = vap->iv_ic;
1205 struct ieee80211_node *ni = vap->iv_bss;
1206 struct sta_table *st = ss->ss_priv;
1207 enum ieee80211_phymode mode;
1208 struct sta_entry *se, *selbs;
1209 uint8_t roamRate, curRate, ucastRate;
1210 int8_t roamRssi, curRssi;
1211
1212 se = sta_lookup(st, ni->ni_macaddr);
1213 if (se == NULL) {
1214 /* XXX something is wrong */
1215 return;
1216 }
1217
1218 mode = ieee80211_chan2mode(ic->ic_bsschan);
1219 roamRate = vap->iv_roamparms[mode].rate;
1220 roamRssi = vap->iv_roamparms[mode].rssi;
1221 ucastRate = vap->iv_txparms[mode].ucastrate;
1222 /* NB: the most up to date rssi is in the node, not the scan cache */
1223 curRssi = ic->ic_node_getrssi(ni);
1224 if (ucastRate == IEEE80211_FIXED_RATE_NONE) {
1225 curRate = ni->ni_txrate;
1226 roamRate &= IEEE80211_RATE_VAL;
1227 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM,
1228 "%s: currssi %d currate %u roamrssi %d roamrate %u\n",
1229 __func__, curRssi, curRate, roamRssi, roamRate);
1230 } else {
1231 curRate = roamRate; /* NB: insure compare below fails */
1232 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM,
1233 "%s: currssi %d roamrssi %d\n", __func__, curRssi, roamRssi);
1234 }
1235 /*
1236 * Check if a new ap should be used and switch.
1237 * XXX deauth current ap
1238 */
1239 if (curRate < roamRate || curRssi < roamRssi) {
1240 if (time_after(ticks, ic->ic_lastscan + vap->iv_scanvalid)) {
1241 /*
1242 * Scan cache contents are too old; force a scan now
1243 * if possible so we have current state to make a
1244 * decision with. We don't kick off a bg scan if
1245 * we're using dynamic turbo and boosted or if the
1246 * channel is busy.
1247 * XXX force immediate switch on scan complete
1248 */
1249 if (!IEEE80211_IS_CHAN_DTURBO(ic->ic_curchan) &&
1250 time_after(ticks, ic->ic_lastdata + vap->iv_bgscanidle))
1251 ieee80211_bg_scan(vap, 0);
1252 return;
1253 }
1254 se->base.se_rssi = curRssi;
1255 selbs = select_bss(ss, vap, IEEE80211_MSG_ROAM);
1256 if (selbs != NULL && selbs != se) {
1257 struct ieee80211_channel *chan;
1258
1259 IEEE80211_DPRINTF(vap,
1260 IEEE80211_MSG_ROAM | IEEE80211_MSG_DEBUG,
1261 "%s: ROAM: curRate %u, roamRate %u, "
1262 "curRssi %d, roamRssi %d\n", __func__,
1263 curRate, roamRate, curRssi, roamRssi);
1264
1265 chan = selbs->base.se_chan;
1266 if (selbs->se_flags & STA_DEMOTE11B)
1267 chan = demote11b(vap, chan);
1268 (void) ieee80211_sta_join(vap, chan, &selbs->base);
1269 }
1270 }
1271}
1272
1273/*
1274 * Age entries in the scan cache.
1275 * XXX also do roaming since it's convenient
1276 */
1277static void
1278sta_age(struct ieee80211_scan_state *ss)
1279{
1280 struct ieee80211vap *vap = ss->ss_vap;
1281
1282 adhoc_age(ss);
1283 /*
1284 * If rate control is enabled check periodically to see if
1285 * we should roam from our current connection to one that
1286 * might be better. This only applies when we're operating
1287 * in sta mode and automatic roaming is set.
1288 * XXX defer if busy
1289 * XXX repeater station
1290 * XXX do when !bgscan?
1291 */
1292 KASSERT(vap->iv_opmode == IEEE80211_M_STA,
1293 ("wrong mode %u", vap->iv_opmode));
1294 if (vap->iv_roaming == IEEE80211_ROAMING_AUTO &&
1295 (vap->iv_ic->ic_flags & IEEE80211_F_BGSCAN) &&
1296 vap->iv_state >= IEEE80211_S_RUN)
1297 /* XXX vap is implicit */
1298 sta_roam_check(ss, vap);
1299}
1300
1301/*
1302 * Iterate over the entries in the scan cache, invoking
1303 * the callback function on each one.
1304 */
1305static void
1306sta_iterate(struct ieee80211_scan_state *ss,
1307 ieee80211_scan_iter_func *f, void *arg)
1308{
1309 struct sta_table *st = ss->ss_priv;
1310 struct sta_entry *se;
1311 u_int gen;
1312
1313 mtx_lock(&st->st_scanlock);
1314 gen = st->st_scaniter++;
1315restart:
1316 mtx_lock(&st->st_lock);
1317 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1318 if (se->se_scangen != gen) {
1319 se->se_scangen = gen;
1320 /* update public state */
1321 se->base.se_age = ticks - se->se_lastupdate;
1322 mtx_unlock(&st->st_lock);
1323 (*f)(arg, &se->base);
1324 goto restart;
1325 }
1326 }
1327 mtx_unlock(&st->st_lock);
1328
1329 mtx_unlock(&st->st_scanlock);
1330}
1331
1332static void
1333sta_assoc_fail(struct ieee80211_scan_state *ss,
1334 const uint8_t macaddr[IEEE80211_ADDR_LEN], int reason)
1335{
1336 struct sta_table *st = ss->ss_priv;
1337 struct sta_entry *se;
1338
1339 se = sta_lookup(st, macaddr);
1340 if (se != NULL) {
1341 se->se_fails++;
1342 se->se_lastfail = ticks;
1343 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN,
1344 macaddr, "%s: reason %u fails %u",
1345 __func__, reason, se->se_fails);
1346 }
1347}
1348
1349static void
1350sta_assoc_success(struct ieee80211_scan_state *ss,
1351 const uint8_t macaddr[IEEE80211_ADDR_LEN])
1352{
1353 struct sta_table *st = ss->ss_priv;
1354 struct sta_entry *se;
1355
1356 se = sta_lookup(st, macaddr);
1357 if (se != NULL) {
1358#if 0
1359 se->se_fails = 0;
1360 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN,
1361 macaddr, "%s: fails %u",
1362 __func__, se->se_fails);
1363#endif
1364 se->se_lastassoc = ticks;
1365 }
1366}
1367
1368static const struct ieee80211_scanner sta_default = {
1369 .scan_name = "default",
1370 .scan_attach = sta_attach,
1371 .scan_detach = sta_detach,
1372 .scan_start = sta_start,
1373 .scan_restart = sta_restart,
1374 .scan_cancel = sta_cancel,
1375 .scan_end = sta_pick_bss,
1376 .scan_flush = sta_flush,
1377 .scan_add = sta_add,
1378 .scan_age = sta_age,
1379 .scan_iterate = sta_iterate,
1380 .scan_assoc_fail = sta_assoc_fail,
1381 .scan_assoc_success = sta_assoc_success,
1382};
1383
1384/*
1385 * Adhoc mode-specific support.
1386 */
1387
1388static const uint16_t adhocWorld[] = /* 36, 40, 44, 48 */
1389{ 5180, 5200, 5220, 5240 };
1390static const uint16_t adhocFcc3[] = /* 36, 40, 44, 48 145, 149, 153, 157, 161, 165 */
1391{ 5180, 5200, 5220, 5240, 5725, 5745, 5765, 5785, 5805, 5825 };
1392static const uint16_t adhocMkk[] = /* 34, 38, 42, 46 */
1393{ 5170, 5190, 5210, 5230 };
1394static const uint16_t adhoc11b[] = /* 10, 11 */
1395{ 2457, 2462 };
1396
1397static const struct scanlist adhocScanTable[] = {
1398 { IEEE80211_MODE_11B, X(adhoc11b) },
1399 { IEEE80211_MODE_11A, X(adhocWorld) },
1400 { IEEE80211_MODE_11A, X(adhocFcc3) },
1401 { IEEE80211_MODE_11B, X(adhocMkk) },
1402 { .list = NULL }
1403};
1404#undef X
1405
1406/*
1407 * Start an adhoc-mode scan by populating the channel list.
1408 */
1409static int
1410adhoc_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1411{
1412 struct sta_table *st = ss->ss_priv;
1413
1414 makescanlist(ss, vap, adhocScanTable);
1415
1416 if (ss->ss_mindwell == 0)
1417 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */
1418 if (ss->ss_maxdwell == 0)
1419 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
1420
1421 st->st_scangen++;
1422 st->st_newscan = 1;
1423
1424 return 0;
1425}
1426
1427/*
1428 * Select a channel to start an adhoc network on.
1429 * The channel list was populated with appropriate
1430 * channels so select one that looks least occupied.
1431 */
1432static struct ieee80211_channel *
1433adhoc_pick_channel(struct ieee80211_scan_state *ss, int flags)
1434{
1435 struct sta_table *st = ss->ss_priv;
1436 struct sta_entry *se;
1437 struct ieee80211_channel *c, *bestchan;
1438 int i, bestrssi, maxrssi;
1439
1440 bestchan = NULL;
1441 bestrssi = -1;
1442
1443 mtx_lock(&st->st_lock);
1444 for (i = 0; i < ss->ss_last; i++) {
1445 c = ss->ss_chans[i];
1446 /* never consider a channel with radar */
1447 if (IEEE80211_IS_CHAN_RADAR(c))
1448 continue;
1449 /* skip channels disallowed by regulatory settings */
1450 if (IEEE80211_IS_CHAN_NOADHOC(c))
1451 continue;
1452 /* check channel attributes for band compatibility */
1453 if (flags != 0 && (c->ic_flags & flags) != flags)
1454 continue;
1455 maxrssi = 0;
1456 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1457 if (se->base.se_chan != c)
1458 continue;
1459 if (se->base.se_rssi > maxrssi)
1460 maxrssi = se->base.se_rssi;
1461 }
1462 if (bestchan == NULL || maxrssi < bestrssi)
1463 bestchan = c;
1464 }
1465 mtx_unlock(&st->st_lock);
1466
1467 return bestchan;
1468}
1469
1470/*
1471 * Pick an ibss network to join or find a channel
1472 * to use to start an ibss network.
1473 */
1474static int
1475adhoc_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1476{
1477 struct sta_table *st = ss->ss_priv;
1478 struct sta_entry *selbs;
1479 struct ieee80211_channel *chan;
1480
1481 KASSERT(vap->iv_opmode == IEEE80211_M_IBSS ||
1482 vap->iv_opmode == IEEE80211_M_AHDEMO,
1483 ("wrong opmode %u", vap->iv_opmode));
1484
1485 if (st->st_newscan) {
1486 sta_update_notseen(st);
1487 st->st_newscan = 0;
1488 }
1489 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1490 /*
1491 * Manual/background scan, don't select+join the
1492 * bss, just return. The scanning framework will
1493 * handle notification that this has completed.
1494 */
1495 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1496 return 1;
1497 }
1498 /*
1499 * Automatic sequencing; look for a candidate and
1500 * if found join the network.
1501 */
1502 /* NB: unlocked read should be ok */
1503 if (TAILQ_FIRST(&st->st_entry) == NULL) {
1504 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1505 "%s: no scan candidate\n", __func__);
1506 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1507 return 0;
1508notfound:
1509 /* NB: never auto-start a tdma network for slot !0 */
1510#ifdef IEEE80211_SUPPORT_TDMA
1511 if (vap->iv_des_nssid &&
1512 ((vap->iv_caps & IEEE80211_C_TDMA) == 0 ||
1513 ieee80211_tdma_getslot(vap) == 0)) {
1514#else
1515 if (vap->iv_des_nssid) {
1516#endif
1517 /*
1518 * No existing adhoc network to join and we have
1519 * an ssid; start one up. If no channel was
1520 * specified, try to select a channel.
1521 */
1522 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC ||
1523 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
1524 struct ieee80211com *ic = vap->iv_ic;
1525
1526 chan = adhoc_pick_channel(ss, 0);
1527 if (chan != NULL)
1528 chan = ieee80211_ht_adjust_channel(ic,
1529 chan, vap->iv_flags_ext);
1530 } else
1531 chan = vap->iv_des_chan;
1532 if (chan != NULL) {
1533 ieee80211_create_ibss(vap, chan);
1534 return 1;
1535 }
1536 }
1537 /*
1538 * If nothing suitable was found decrement
1539 * the failure counts so entries will be
1540 * reconsidered the next time around. We
1541 * really want to do this only for sta's
1542 * where we've previously had some success.
1543 */
1544 sta_dec_fails(st);
1545 st->st_newscan = 1;
1546 return 0; /* restart scan */
1547 }
1548 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1549 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1550 return (selbs != NULL);
1551 if (selbs == NULL)
1552 goto notfound;
1553 chan = selbs->base.se_chan;
1554 if (selbs->se_flags & STA_DEMOTE11B)
1555 chan = demote11b(vap, chan);
1556 if (!ieee80211_sta_join(vap, chan, &selbs->base))
1557 goto notfound;
1558 return 1; /* terminate scan */
1559}
1560
1561/*
1562 * Age entries in the scan cache.
1563 */
1564static void
1565adhoc_age(struct ieee80211_scan_state *ss)
1566{
1567 struct sta_table *st = ss->ss_priv;
1568 struct sta_entry *se, *next;
1569
1570 mtx_lock(&st->st_lock);
1571 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) {
1572 if (se->se_notseen > STA_PURGE_SCANS) {
1573 TAILQ_REMOVE(&st->st_entry, se, se_list);
1574 LIST_REMOVE(se, se_hash);
1575 ieee80211_ies_cleanup(&se->base.se_ies);
1576 free(se, M_80211_SCAN);
1577 }
1578 }
1579 mtx_unlock(&st->st_lock);
1580}
1581
1582static const struct ieee80211_scanner adhoc_default = {
1583 .scan_name = "default",
1584 .scan_attach = sta_attach,
1585 .scan_detach = sta_detach,
1586 .scan_start = adhoc_start,
1587 .scan_restart = sta_restart,
1588 .scan_cancel = sta_cancel,
1589 .scan_end = adhoc_pick_bss,
1590 .scan_flush = sta_flush,
1591 .scan_pickchan = adhoc_pick_channel,
1592 .scan_add = sta_add,
1593 .scan_age = adhoc_age,
1594 .scan_iterate = sta_iterate,
1595 .scan_assoc_fail = sta_assoc_fail,
1596 .scan_assoc_success = sta_assoc_success,
1597};
1598
1599static void
1600ap_force_promisc(struct ieee80211com *ic)
1601{
1602 struct ifnet *ifp = ic->ic_ifp;
1603
1604 IEEE80211_LOCK(ic);
1605 /* set interface into promiscuous mode */
1606 ifp->if_flags |= IFF_PROMISC;
1607 ic->ic_update_promisc(ifp);
1608 IEEE80211_UNLOCK(ic);
1609}
1610
1611static void
1612ap_reset_promisc(struct ieee80211com *ic)
1613{
1614 IEEE80211_LOCK(ic);
1615 ieee80211_syncifflag_locked(ic, IFF_PROMISC);
1616 IEEE80211_UNLOCK(ic);
1617}
1618
1619static int
1620ap_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1621{
1622 struct sta_table *st = ss->ss_priv;
1623
1624 makescanlist(ss, vap, staScanTable);
1625
1626 if (ss->ss_mindwell == 0)
1627 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */
1628 if (ss->ss_maxdwell == 0)
1629 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
1630
1631 st->st_scangen++;
1632 st->st_newscan = 1;
1633
1634 ap_force_promisc(vap->iv_ic);
1635 return 0;
1636}
1637
1638/*
1639 * Cancel an ongoing scan.
1640 */
1641static int
1642ap_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1643{
1644 ap_reset_promisc(vap->iv_ic);
1645 return 0;
1646}
1647
1648/*
1649 * Pick a quiet channel to use for ap operation.
1650 */
1651static struct ieee80211_channel *
1652ap_pick_channel(struct ieee80211_scan_state *ss, int flags)
1653{
1654 struct sta_table *st = ss->ss_priv;
1655 struct ieee80211_channel *bestchan = NULL;
1656 int i;
1657
1658 /* XXX select channel more intelligently, e.g. channel spread, power */
1659 /* NB: use scan list order to preserve channel preference */
1660 for (i = 0; i < ss->ss_last; i++) {
1661 struct ieee80211_channel *chan = ss->ss_chans[i];
1662 /*
1663 * If the channel is unoccupied the max rssi
1664 * should be zero; just take it. Otherwise
1665 * track the channel with the lowest rssi and
1666 * use that when all channels appear occupied.
1667 */
1668 if (IEEE80211_IS_CHAN_RADAR(chan))
1669 continue;
1670 if (IEEE80211_IS_CHAN_NOHOSTAP(chan))
1671 continue;
1672 /* check channel attributes for band compatibility */
1673 if (flags != 0 && (chan->ic_flags & flags) != flags)
1674 continue;
1675 KASSERT(sizeof(chan->ic_ieee) == 1, ("ic_chan size"));
1676 /* XXX channel have interference */
1677 if (st->st_maxrssi[chan->ic_ieee] == 0) {
1678 /* XXX use other considerations */
1679 return chan;
1680 }
1681 if (bestchan == NULL ||
1682 st->st_maxrssi[chan->ic_ieee] < st->st_maxrssi[bestchan->ic_ieee])
1683 bestchan = chan;
1684 }
1685 return bestchan;
1686}
1687
1688/*
1689 * Pick a quiet channel to use for ap operation.
1690 */
1691static int
1692ap_end(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1693{
1694 struct ieee80211com *ic = vap->iv_ic;
1695 struct ieee80211_channel *bestchan;
1696
1697 KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP,
1698 ("wrong opmode %u", vap->iv_opmode));
1699 bestchan = ap_pick_channel(ss, 0);
1700 if (bestchan == NULL) {
1701 /* no suitable channel, should not happen */
1702 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1703 "%s: no suitable channel! (should not happen)\n", __func__);
1704 /* XXX print something? */
1705 return 0; /* restart scan */
1706 }
1707 /*
1708 * If this is a dynamic turbo channel, start with the unboosted one.
1709 */
1710 if (IEEE80211_IS_CHAN_TURBO(bestchan)) {
1711 bestchan = ieee80211_find_channel(ic, bestchan->ic_freq,
1712 bestchan->ic_flags & ~IEEE80211_CHAN_TURBO);
1713 if (bestchan == NULL) {
1714 /* should never happen ?? */
1715 return 0;
1716 }
1717 }
1718 ap_reset_promisc(ic);
1719 if (ss->ss_flags & (IEEE80211_SCAN_NOPICK | IEEE80211_SCAN_NOJOIN)) {
1720 /*
1721 * Manual/background scan, don't select+join the
1722 * bss, just return. The scanning framework will
1723 * handle notification that this has completed.
1724 */
1725 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1726 return 1;
1727 }
1728 ieee80211_create_ibss(vap,
1729 ieee80211_ht_adjust_channel(ic, bestchan, vap->iv_flags_ext));
1730 return 1;
1731}
1732
1733static const struct ieee80211_scanner ap_default = {
1734 .scan_name = "default",
1735 .scan_attach = sta_attach,
1736 .scan_detach = sta_detach,
1737 .scan_start = ap_start,
1738 .scan_restart = sta_restart,
1739 .scan_cancel = ap_cancel,
1740 .scan_end = ap_end,
1741 .scan_flush = sta_flush,
1742 .scan_pickchan = ap_pick_channel,
1743 .scan_add = sta_add,
1744 .scan_age = adhoc_age,
1745 .scan_iterate = sta_iterate,
1746 .scan_assoc_success = sta_assoc_success,
1747 .scan_assoc_fail = sta_assoc_fail,
1748};
1749
1750/*
1751 * Module glue.
1752 */
1753IEEE80211_SCANNER_MODULE(sta, 1);
1754IEEE80211_SCANNER_ALG(sta, IEEE80211_M_STA, sta_default);
1755IEEE80211_SCANNER_ALG(ibss, IEEE80211_M_IBSS, adhoc_default);
1756IEEE80211_SCANNER_ALG(ahdemo, IEEE80211_M_AHDEMO, adhoc_default);
1757IEEE80211_SCANNER_ALG(ap, IEEE80211_M_HOSTAP, ap_default);