2 * Copyright (c) 2002-2009 Sam Leffler, Errno Consulting
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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.
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
30 * IEEE 802.11 station scanning support.
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/endian.h>
38 #include <sys/malloc.h>
39 #include <sys/module.h>
41 #include <sys/socket.h>
44 #include <net/if_var.h>
45 #include <net/if_media.h>
46 #include <net/ethernet.h>
48 #include <net80211/ieee80211_var.h>
49 #include <net80211/ieee80211_input.h>
50 #include <net80211/ieee80211_regdomain.h>
51 #ifdef IEEE80211_SUPPORT_TDMA
52 #include <net80211/ieee80211_tdma.h>
54 #ifdef IEEE80211_SUPPORT_MESH
55 #include <net80211/ieee80211_mesh.h>
57 #include <net80211/ieee80211_ratectl.h>
58 #include <net80211/ieee80211_vht.h>
63 * Parameters for managing cache entries:
65 * o a station with STA_FAILS_MAX failures is not considered
66 * when picking a candidate
67 * o a station that hasn't had an update in STA_PURGE_SCANS
68 * (background) scans is discarded
69 * o after STA_FAILS_AGE seconds we clear the failure count
71 #define STA_FAILS_MAX 2 /* assoc failures before ignored */
72 #define STA_FAILS_AGE (2*60) /* time before clearing fails (secs) */
73 #define STA_PURGE_SCANS 2 /* age for purging entries (scans) */
76 #define STA_RSSI_MIN 8 /* min acceptable rssi */
77 #define STA_RSSI_MAX 40 /* max rssi for comparison */
80 struct ieee80211_scan_entry base;
81 TAILQ_ENTRY(sta_entry) se_list;
82 LIST_ENTRY(sta_entry) se_hash;
83 uint8_t se_fails; /* failure to associate count */
84 uint8_t se_seen; /* seen during current scan */
85 uint8_t se_notseen; /* not seen in previous scans */
87 #define STA_DEMOTE11B 0x01 /* match w/ demoted 11b chan */
88 uint32_t se_avgrssi; /* LPF rssi state */
89 unsigned long se_lastupdate; /* time of last update */
90 unsigned long se_lastfail; /* time of last failure */
91 unsigned long se_lastassoc; /* time of last association */
92 u_int se_scangen; /* iterator scan gen# */
93 u_int se_countrygen; /* gen# of last cc notify */
96 #define STA_HASHSIZE 32
97 /* simple hash is enough for variation of macaddr */
98 #define STA_HASH(addr) \
99 (((const uint8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % STA_HASHSIZE)
101 #define MAX_IEEE_CHAN 256 /* max acceptable IEEE chan # */
102 CTASSERT(MAX_IEEE_CHAN >= 256);
105 ieee80211_scan_table_lock_t st_lock; /* on scan table */
106 TAILQ_HEAD(, sta_entry) st_entry; /* all entries */
107 LIST_HEAD(, sta_entry) st_hash[STA_HASHSIZE];
108 ieee80211_scan_iter_lock_t st_scanlock; /* on st_scaniter */
109 u_int st_scaniter; /* gen# for iterator */
110 u_int st_scangen; /* scan generation # */
112 /* ap-related state */
113 int st_maxrssi[MAX_IEEE_CHAN];
116 static void sta_flush_table(struct sta_table *);
118 * match_bss returns a bitmask describing if an entry is suitable
119 * for use. If non-zero the entry was deemed not suitable and it's
120 * contents explains why. The following flags are or'd to to this
121 * mask and can be used to figure out why the entry was rejected.
123 #define MATCH_CHANNEL 0x00001 /* channel mismatch */
124 #define MATCH_CAPINFO 0x00002 /* capabilities mismatch, e.g. no ess */
125 #define MATCH_PRIVACY 0x00004 /* privacy mismatch */
126 #define MATCH_RATE 0x00008 /* rate set mismatch */
127 #define MATCH_SSID 0x00010 /* ssid mismatch */
128 #define MATCH_BSSID 0x00020 /* bssid mismatch */
129 #define MATCH_FAILS 0x00040 /* too many failed auth attempts */
130 #define MATCH_NOTSEEN 0x00080 /* not seen in recent scans */
131 #define MATCH_RSSI 0x00100 /* rssi deemed too low to use */
132 #define MATCH_CC 0x00200 /* country code mismatch */
133 #ifdef IEEE80211_SUPPORT_TDMA
134 #define MATCH_TDMA_NOIE 0x00400 /* no TDMA ie */
135 #define MATCH_TDMA_NOTMASTER 0x00800 /* not TDMA master */
136 #define MATCH_TDMA_NOSLOT 0x01000 /* all TDMA slots occupied */
137 #define MATCH_TDMA_LOCAL 0x02000 /* local address */
138 #define MATCH_TDMA_VERSION 0x04000 /* protocol version mismatch */
140 #define MATCH_MESH_NOID 0x10000 /* no MESHID ie */
141 #define MATCH_MESHID 0x20000 /* meshid mismatch */
142 static int match_bss(struct ieee80211vap *,
143 const struct ieee80211_scan_state *, struct sta_entry *, int);
144 static void adhoc_age(struct ieee80211_scan_state *);
147 isocmp(const uint8_t cc1[], const uint8_t cc2[])
149 return (cc1[0] == cc2[0] && cc1[1] == cc2[1]);
152 /* number of references from net80211 layer */
153 static int nrefs = 0;
157 IEEE80211_SCANNER_MODULE(sta, 1);
160 * Attach prior to any scanning work.
163 sta_attach(struct ieee80211_scan_state *ss)
165 struct sta_table *st;
167 st = (struct sta_table *) IEEE80211_MALLOC(sizeof(struct sta_table),
169 IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
172 IEEE80211_SCAN_TABLE_LOCK_INIT(st, "scantable");
173 IEEE80211_SCAN_ITER_LOCK_INIT(st, "scangen");
174 TAILQ_INIT(&st->st_entry);
176 nrefs++; /* NB: we assume caller locking */
181 * Cleanup any private state.
184 sta_detach(struct ieee80211_scan_state *ss)
186 struct sta_table *st = ss->ss_priv;
190 IEEE80211_SCAN_TABLE_LOCK_DESTROY(st);
191 IEEE80211_SCAN_ITER_LOCK_DESTROY(st);
192 IEEE80211_FREE(st, M_80211_SCAN);
193 KASSERT(nrefs > 0, ("imbalanced attach/detach"));
194 nrefs--; /* NB: we assume caller locking */
200 * Flush all per-scan state.
203 sta_flush(struct ieee80211_scan_state *ss)
205 struct sta_table *st = ss->ss_priv;
207 IEEE80211_SCAN_TABLE_LOCK(st);
209 IEEE80211_SCAN_TABLE_UNLOCK(st);
215 * Flush all entries in the scan cache.
218 sta_flush_table(struct sta_table *st)
220 struct sta_entry *se, *next;
222 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) {
223 TAILQ_REMOVE(&st->st_entry, se, se_list);
224 LIST_REMOVE(se, se_hash);
225 ieee80211_ies_cleanup(&se->base.se_ies);
226 IEEE80211_FREE(se, M_80211_SCAN);
228 memset(st->st_maxrssi, 0, sizeof(st->st_maxrssi));
232 * Process a beacon or probe response frame; create an
233 * entry in the scan cache or update any previous entry.
236 sta_add(struct ieee80211_scan_state *ss,
237 struct ieee80211_channel *curchan,
238 const struct ieee80211_scanparams *sp,
239 const struct ieee80211_frame *wh,
240 int subtype, int rssi, int noise)
242 #define ISPROBE(_st) ((_st) == IEEE80211_FC0_SUBTYPE_PROBE_RESP)
243 #define PICK1ST(_ss) \
244 ((ss->ss_flags & (IEEE80211_SCAN_PICK1ST | IEEE80211_SCAN_GOTPICK)) == \
245 IEEE80211_SCAN_PICK1ST)
246 struct sta_table *st = ss->ss_priv;
247 const uint8_t *macaddr = wh->i_addr2;
248 struct ieee80211vap *vap = ss->ss_vap;
249 struct ieee80211com *ic = vap->iv_ic;
250 struct ieee80211_channel *c;
251 struct sta_entry *se;
252 struct ieee80211_scan_entry *ise;
255 hash = STA_HASH(macaddr);
257 IEEE80211_SCAN_TABLE_LOCK(st);
258 LIST_FOREACH(se, &st->st_hash[hash], se_hash)
259 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr))
261 se = (struct sta_entry *) IEEE80211_MALLOC(sizeof(struct sta_entry),
262 M_80211_SCAN, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
264 IEEE80211_SCAN_TABLE_UNLOCK(st);
267 se->se_scangen = st->st_scaniter-1;
268 se->se_avgrssi = IEEE80211_RSSI_DUMMY_MARKER;
269 IEEE80211_ADDR_COPY(se->base.se_macaddr, macaddr);
270 TAILQ_INSERT_TAIL(&st->st_entry, se, se_list);
271 LIST_INSERT_HEAD(&st->st_hash[hash], se, se_hash);
274 /* XXX ap beaconing multiple ssid w/ same bssid */
275 if (sp->ssid[1] != 0 &&
276 (ISPROBE(subtype) || ise->se_ssid[1] == 0))
277 memcpy(ise->se_ssid, sp->ssid, 2+sp->ssid[1]);
278 KASSERT(sp->rates[1] <= IEEE80211_RATE_MAXSIZE,
279 ("rate set too large: %u", sp->rates[1]));
280 memcpy(ise->se_rates, sp->rates, 2+sp->rates[1]);
281 if (sp->xrates != NULL) {
282 /* XXX validate xrates[1] */
283 KASSERT(sp->xrates[1] <= IEEE80211_RATE_MAXSIZE,
284 ("xrate set too large: %u", sp->xrates[1]));
285 memcpy(ise->se_xrates, sp->xrates, 2+sp->xrates[1]);
287 ise->se_xrates[1] = 0;
288 IEEE80211_ADDR_COPY(ise->se_bssid, wh->i_addr3);
289 if ((sp->status & IEEE80211_BPARSE_OFFCHAN) == 0) {
291 * Record rssi data using extended precision LPF filter.
293 * NB: use only on-channel data to insure we get a good
294 * estimate of the signal we'll see when associated.
296 IEEE80211_RSSI_LPF(se->se_avgrssi, rssi);
297 ise->se_rssi = IEEE80211_RSSI_GET(se->se_avgrssi);
298 ise->se_noise = noise;
300 memcpy(ise->se_tstamp.data, sp->tstamp, sizeof(ise->se_tstamp));
301 ise->se_intval = sp->bintval;
302 ise->se_capinfo = sp->capinfo;
303 #ifdef IEEE80211_SUPPORT_MESH
304 if (sp->meshid != NULL && sp->meshid[1] != 0)
305 memcpy(ise->se_meshid, sp->meshid, 2+sp->meshid[1]);
308 * Beware of overriding se_chan for frames seen
309 * off-channel; this can cause us to attempt an
310 * association on the wrong channel.
312 if (sp->status & IEEE80211_BPARSE_OFFCHAN) {
314 * Off-channel, locate the home/bss channel for the sta
315 * using the value broadcast in the DSPARMS ie. We know
316 * sp->chan has this value because it's used to calculate
317 * IEEE80211_BPARSE_OFFCHAN.
319 c = ieee80211_find_channel_byieee(ic, sp->chan,
323 } else if (ise->se_chan == NULL) {
324 /* should not happen, pick something */
325 ise->se_chan = curchan;
328 ise->se_chan = curchan;
331 if (IEEE80211_IS_CHAN_VHT(ise->se_chan) && sp->vhtcap == NULL) {
332 IEEE80211_DPRINTF(vap, IEEE80211_MSG_11N,
333 "%s: demoting VHT->HT %d/0x%08x\n",
334 __func__, ise->se_chan->ic_freq, ise->se_chan->ic_flags);
335 /* Demote legacy networks to a non-VHT channel. */
336 c = ieee80211_find_channel(ic, ise->se_chan->ic_freq,
337 ise->se_chan->ic_flags & ~IEEE80211_CHAN_VHT);
339 ("no non-VHT channel %u", ise->se_chan->ic_ieee));
344 if (IEEE80211_IS_CHAN_HT(ise->se_chan) && sp->htcap == NULL) {
345 /* Demote legacy networks to a non-HT channel. */
346 IEEE80211_DPRINTF(vap, IEEE80211_MSG_11N,
347 "%s: demoting HT->legacy %d/0x%08x\n",
348 __func__, ise->se_chan->ic_freq, ise->se_chan->ic_flags);
349 c = ieee80211_find_channel(ic, ise->se_chan->ic_freq,
350 ise->se_chan->ic_flags & ~IEEE80211_CHAN_HT);
352 ("no legacy channel %u", ise->se_chan->ic_ieee));
356 ise->se_fhdwell = sp->fhdwell;
357 ise->se_fhindex = sp->fhindex;
358 ise->se_erp = sp->erp;
359 ise->se_timoff = sp->timoff;
360 if (sp->tim != NULL) {
361 const struct ieee80211_tim_ie *tim =
362 (const struct ieee80211_tim_ie *) sp->tim;
363 ise->se_dtimperiod = tim->tim_period;
365 if (sp->country != NULL) {
366 const struct ieee80211_country_ie *cie =
367 (const struct ieee80211_country_ie *) sp->country;
369 * If 11d is enabled and we're attempting to join a bss
370 * that advertises it's country code then compare our
371 * current settings to what we fetched from the country ie.
372 * If our country code is unspecified or different then
373 * dispatch an event to user space that identifies the
374 * country code so our regdomain config can be changed.
376 /* XXX only for STA mode? */
377 if ((IEEE80211_IS_CHAN_11D(ise->se_chan) ||
378 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) &&
379 (ic->ic_regdomain.country == CTRY_DEFAULT ||
380 !isocmp(cie->cc, ic->ic_regdomain.isocc))) {
381 /* only issue one notify event per scan */
382 if (se->se_countrygen != st->st_scangen) {
383 ieee80211_notify_country(vap, ise->se_bssid,
385 se->se_countrygen = st->st_scangen;
388 ise->se_cc[0] = cie->cc[0];
389 ise->se_cc[1] = cie->cc[1];
391 /* NB: no need to setup ie ptrs; they are not (currently) used */
392 (void) ieee80211_ies_init(&ise->se_ies, sp->ies, sp->ies_len);
394 /* clear failure count after STA_FAIL_AGE passes */
395 if (se->se_fails && (ticks - se->se_lastfail) > STA_FAILS_AGE*hz) {
397 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, macaddr,
398 "%s: fails %u", __func__, se->se_fails);
401 se->se_lastupdate = ticks; /* update time */
405 KASSERT(sizeof(sp->bchan) == 1, ("bchan size"));
406 if (rssi > st->st_maxrssi[sp->bchan])
407 st->st_maxrssi[sp->bchan] = rssi;
409 IEEE80211_SCAN_TABLE_UNLOCK(st);
412 * If looking for a quick choice and nothing's
413 * been found check here.
415 if (PICK1ST(ss) && match_bss(vap, ss, se, IEEE80211_MSG_SCAN) == 0)
416 ss->ss_flags |= IEEE80211_SCAN_GOTPICK;
424 * Check if a channel is excluded by user request.
427 isexcluded(struct ieee80211vap *vap, const struct ieee80211_channel *c)
429 return (isclr(vap->iv_ic->ic_chan_active, c->ic_ieee) ||
430 (vap->iv_des_chan != IEEE80211_CHAN_ANYC &&
431 c->ic_freq != vap->iv_des_chan->ic_freq));
434 static struct ieee80211_channel *
435 find11gchannel(struct ieee80211com *ic, int i, int freq)
437 struct ieee80211_channel *c;
441 * The normal ordering in the channel list is b channel
442 * immediately followed by g so optimize the search for
443 * this. We'll still do a full search just in case.
445 for (j = i+1; j < ic->ic_nchans; j++) {
446 c = &ic->ic_channels[j];
447 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c))
450 for (j = 0; j < i; j++) {
451 c = &ic->ic_channels[j];
452 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c))
458 static const u_int chanflags[IEEE80211_MODE_MAX] = {
459 [IEEE80211_MODE_AUTO] = IEEE80211_CHAN_B,
460 [IEEE80211_MODE_11A] = IEEE80211_CHAN_A,
461 [IEEE80211_MODE_11B] = IEEE80211_CHAN_B,
462 [IEEE80211_MODE_11G] = IEEE80211_CHAN_G,
463 [IEEE80211_MODE_FH] = IEEE80211_CHAN_FHSS,
464 /* check base channel */
465 [IEEE80211_MODE_TURBO_A] = IEEE80211_CHAN_A,
466 [IEEE80211_MODE_TURBO_G] = IEEE80211_CHAN_G,
467 [IEEE80211_MODE_STURBO_A] = IEEE80211_CHAN_ST,
468 [IEEE80211_MODE_HALF] = IEEE80211_CHAN_HALF,
469 [IEEE80211_MODE_QUARTER] = IEEE80211_CHAN_QUARTER,
471 [IEEE80211_MODE_11NA] = IEEE80211_CHAN_A,
472 [IEEE80211_MODE_11NG] = IEEE80211_CHAN_G,
476 add_channels(struct ieee80211vap *vap,
477 struct ieee80211_scan_state *ss,
478 enum ieee80211_phymode mode, const uint16_t freq[], int nfreq)
480 struct ieee80211com *ic = vap->iv_ic;
481 struct ieee80211_channel *c, *cg;
485 KASSERT(mode < nitems(chanflags), ("Unexpected mode %u", mode));
486 modeflags = chanflags[mode];
487 for (i = 0; i < nfreq; i++) {
488 if (ss->ss_last >= IEEE80211_SCAN_MAX)
491 c = ieee80211_find_channel(ic, freq[i], modeflags);
492 if (c == NULL || isexcluded(vap, c))
494 if (mode == IEEE80211_MODE_AUTO) {
496 * XXX special-case 11b/g channels so we select
497 * the g channel if both are present.
499 if (IEEE80211_IS_CHAN_B(c) &&
500 (cg = find11gchannel(ic, i, c->ic_freq)) != NULL)
503 ss->ss_chans[ss->ss_last++] = c;
510 const uint16_t *list;
514 checktable(const struct scanlist *scan, const struct ieee80211_channel *c)
518 for (; scan->list != NULL; scan++) {
519 for (i = 0; i < scan->count; i++)
520 if (scan->list[i] == c->ic_freq)
527 onscanlist(const struct ieee80211_scan_state *ss,
528 const struct ieee80211_channel *c)
532 for (i = 0; i < ss->ss_last; i++)
533 if (ss->ss_chans[i] == c)
539 sweepchannels(struct ieee80211_scan_state *ss, struct ieee80211vap *vap,
540 const struct scanlist table[])
542 struct ieee80211com *ic = vap->iv_ic;
543 struct ieee80211_channel *c;
546 for (i = 0; i < ic->ic_nchans; i++) {
547 if (ss->ss_last >= IEEE80211_SCAN_MAX)
550 c = &ic->ic_channels[i];
552 * Ignore dynamic turbo channels; we scan them
553 * in normal mode (i.e. not boosted). Likewise
554 * for HT/VHT channels, they get scanned using
557 if (IEEE80211_IS_CHAN_DTURBO(c) || IEEE80211_IS_CHAN_HT(c) ||
558 IEEE80211_IS_CHAN_VHT(c))
562 * If a desired mode was specified, scan only
563 * channels that satisfy that constraint.
565 if (vap->iv_des_mode != IEEE80211_MODE_AUTO &&
566 vap->iv_des_mode != ieee80211_chan2mode(c))
570 * Skip channels excluded by user request.
572 if (isexcluded(vap, c))
576 * Add the channel unless it is listed in the
577 * fixed scan order tables. This insures we
578 * don't sweep back in channels we filtered out
581 if (checktable(table, c))
584 /* Add channel to scanning list. */
585 ss->ss_chans[ss->ss_last++] = c;
588 * Explicitly add any desired channel if:
589 * - not already on the scan list
590 * - allowed by any desired mode constraint
591 * - there is space in the scan list
592 * This allows the channel to be used when the filtering
593 * mechanisms would otherwise elide it (e.g HT, turbo).
595 c = vap->iv_des_chan;
596 if (c != IEEE80211_CHAN_ANYC &&
597 !onscanlist(ss, c) &&
598 (vap->iv_des_mode == IEEE80211_MODE_AUTO ||
599 vap->iv_des_mode == ieee80211_chan2mode(c)) &&
600 ss->ss_last < IEEE80211_SCAN_MAX)
601 ss->ss_chans[ss->ss_last++] = c;
605 makescanlist(struct ieee80211_scan_state *ss, struct ieee80211vap *vap,
606 const struct scanlist table[])
608 const struct scanlist *scan;
609 enum ieee80211_phymode mode;
613 * Use the table of ordered channels to construct the list
614 * of channels for scanning. Any channels in the ordered
615 * list not in the master list will be discarded.
617 for (scan = table; scan->list != NULL; scan++) {
619 if (vap->iv_des_mode != IEEE80211_MODE_AUTO) {
621 * If a desired mode was specified, scan only
622 * channels that satisfy that constraint.
624 if (vap->iv_des_mode != mode) {
626 * The scan table marks 2.4Ghz channels as b
627 * so if the desired mode is 11g, then use
628 * the 11b channel list but upgrade the mode.
630 if (vap->iv_des_mode == IEEE80211_MODE_11G) {
631 if (mode == IEEE80211_MODE_11G) /* Skip the G check */
633 else if (mode == IEEE80211_MODE_11B)
634 mode = IEEE80211_MODE_11G; /* upgrade */
639 * This lets add_channels upgrade an 11b channel
640 * to 11g if available.
642 if (mode == IEEE80211_MODE_11B)
643 mode = IEEE80211_MODE_AUTO;
645 #ifdef IEEE80211_F_XR
646 /* XR does not operate on turbo channels */
647 if ((vap->iv_flags & IEEE80211_F_XR) &&
648 (mode == IEEE80211_MODE_TURBO_A ||
649 mode == IEEE80211_MODE_TURBO_G ||
650 mode == IEEE80211_MODE_STURBO_A))
654 * Add the list of the channels; any that are not
655 * in the master channel list will be discarded.
657 add_channels(vap, ss, mode, scan->list, scan->count);
661 * Add the channels from the ic that are not present
664 sweepchannels(ss, vap, table);
667 static const uint16_t rcl1[] = /* 8 FCC channel: 52, 56, 60, 64, 36, 40, 44, 48 */
668 { 5260, 5280, 5300, 5320, 5180, 5200, 5220, 5240 };
669 static const uint16_t rcl2[] = /* 4 MKK channels: 34, 38, 42, 46 */
670 { 5170, 5190, 5210, 5230 };
671 static const uint16_t rcl3[] = /* 2.4Ghz ch: 1,6,11,7,13 */
672 { 2412, 2437, 2462, 2442, 2472 };
673 static const uint16_t rcl4[] = /* 5 FCC channel: 149, 153, 161, 165 */
674 { 5745, 5765, 5785, 5805, 5825 };
675 static const uint16_t rcl7[] = /* 11 ETSI channel: 100,104,108,112,116,120,124,128,132,136,140 */
676 { 5500, 5520, 5540, 5560, 5580, 5600, 5620, 5640, 5660, 5680, 5700 };
677 static const uint16_t rcl8[] = /* 2.4Ghz ch: 2,3,4,5,8,9,10,12 */
678 { 2417, 2422, 2427, 2432, 2447, 2452, 2457, 2467 };
679 static const uint16_t rcl9[] = /* 2.4Ghz ch: 14 */
681 static const uint16_t rcl10[] = /* Added Korean channels 2312-2372 */
682 { 2312, 2317, 2322, 2327, 2332, 2337, 2342, 2347, 2352, 2357, 2362, 2367, 2372 };
683 static const uint16_t rcl11[] = /* Added Japan channels in 4.9/5.0 spectrum */
684 { 5040, 5060, 5080, 4920, 4940, 4960, 4980 };
685 #ifdef ATH_TURBO_SCAN
686 static const uint16_t rcl5[] = /* 3 static turbo channels */
687 { 5210, 5250, 5290 };
688 static const uint16_t rcl6[] = /* 2 static turbo channels */
690 static const uint16_t rcl6x[] = /* 4 FCC3 turbo channels */
691 { 5540, 5580, 5620, 5660 };
692 static const uint16_t rcl12[] = /* 2.4Ghz Turbo channel 6 */
694 static const uint16_t rcl13[] = /* dynamic Turbo channels */
695 { 5200, 5240, 5280, 5765, 5805 };
696 #endif /* ATH_TURBO_SCAN */
698 #define X(a) .count = sizeof(a)/sizeof(a[0]), .list = a
700 static const struct scanlist staScanTable[] = {
701 { IEEE80211_MODE_11B, X(rcl3) },
702 { IEEE80211_MODE_11A, X(rcl1) },
703 { IEEE80211_MODE_11A, X(rcl2) },
704 { IEEE80211_MODE_11B, X(rcl8) },
705 { IEEE80211_MODE_11B, X(rcl9) },
706 { IEEE80211_MODE_11A, X(rcl4) },
707 #ifdef ATH_TURBO_SCAN
708 { IEEE80211_MODE_STURBO_A, X(rcl5) },
709 { IEEE80211_MODE_STURBO_A, X(rcl6) },
710 { IEEE80211_MODE_TURBO_A, X(rcl6x) },
711 { IEEE80211_MODE_TURBO_A, X(rcl13) },
712 #endif /* ATH_TURBO_SCAN */
713 { IEEE80211_MODE_11A, X(rcl7) },
714 { IEEE80211_MODE_11B, X(rcl10) },
715 { IEEE80211_MODE_11A, X(rcl11) },
716 #ifdef ATH_TURBO_SCAN
717 { IEEE80211_MODE_TURBO_G, X(rcl12) },
718 #endif /* ATH_TURBO_SCAN */
723 * Start a station-mode scan by populating the channel list.
726 sta_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
728 struct sta_table *st = ss->ss_priv;
730 makescanlist(ss, vap, staScanTable);
732 if (ss->ss_mindwell == 0)
733 ss->ss_mindwell = msecs_to_ticks(20); /* 20ms */
734 if (ss->ss_maxdwell == 0)
735 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
744 * Restart a scan, typically a bg scan but can
745 * also be a fg scan that came up empty.
748 sta_restart(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
750 struct sta_table *st = ss->ss_priv;
757 * Cancel an ongoing scan.
760 sta_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
766 * Demote any supplied 11g channel to 11b. There should
767 * always be an 11b channel but we check anyway...
769 static struct ieee80211_channel *
770 demote11b(struct ieee80211vap *vap, struct ieee80211_channel *chan)
772 struct ieee80211_channel *c;
774 if (IEEE80211_IS_CHAN_ANYG(chan) &&
775 vap->iv_des_mode == IEEE80211_MODE_AUTO) {
776 c = ieee80211_find_channel(vap->iv_ic, chan->ic_freq,
777 (chan->ic_flags &~ (IEEE80211_CHAN_PUREG | IEEE80211_CHAN_G)) |
786 maxrate(const struct ieee80211_scan_entry *se)
788 const struct ieee80211_ie_htcap *htcap =
789 (const struct ieee80211_ie_htcap *) se->se_ies.htcap_ie;
790 int rmax, r, i, txstream;
797 * HT station; inspect supported MCS and then adjust
798 * rate by channel width.
800 txparams = htcap->hc_mcsset[12];
801 if (txparams & 0x3) {
803 * TX MCS parameters defined and not equal to RX,
804 * extract the number of spartial streams and
805 * map it to the highest MCS rate.
807 txstream = ((txparams & 0xc) >> 2) + 1;
808 i = txstream * 8 - 1;
810 for (i = 31; i >= 0 && isclr(htcap->hc_mcsset, i); i--);
812 caps = le16dec(&htcap->hc_cap);
813 if ((caps & IEEE80211_HTCAP_CHWIDTH40) &&
814 (caps & IEEE80211_HTCAP_SHORTGI40))
815 rmax = ieee80211_htrates[i].ht40_rate_400ns;
816 else if (caps & IEEE80211_HTCAP_CHWIDTH40)
817 rmax = ieee80211_htrates[i].ht40_rate_800ns;
818 else if (caps & IEEE80211_HTCAP_SHORTGI20)
819 rmax = ieee80211_htrates[i].ht20_rate_400ns;
821 rmax = ieee80211_htrates[i].ht20_rate_800ns;
824 for (i = 0; i < se->se_rates[1]; i++) {
825 r = se->se_rates[2+i] & IEEE80211_RATE_VAL;
829 for (i = 0; i < se->se_xrates[1]; i++) {
830 r = se->se_xrates[2+i] & IEEE80211_RATE_VAL;
838 * Compare the capabilities of two entries and decide which is
839 * more desirable (return >0 if a is considered better). Note
840 * that we assume compatibility/usability has already been checked
841 * so we don't need to (e.g. validate whether privacy is supported).
842 * Used to select the best scan candidate for association in a BSS.
844 * TODO: should we take 11n, 11ac into account when selecting the
845 * best? Right now it just compares frequency band and RSSI.
848 sta_compare(const struct sta_entry *a, const struct sta_entry *b)
850 #define PREFER(_a,_b,_what) do { \
851 if (((_a) ^ (_b)) & (_what)) \
852 return ((_a) & (_what)) ? 1 : -1; \
858 /* privacy support */
859 PREFER(a->base.se_capinfo, b->base.se_capinfo,
860 IEEE80211_CAPINFO_PRIVACY);
862 /* compare count of previous failures */
863 weight = b->se_fails - a->se_fails;
868 * Compare rssi. If the two are considered equivalent
869 * then fallback to other criteria. We threshold the
870 * comparisons to avoid selecting an ap purely by rssi
871 * when both values may be good but one ap is otherwise
872 * more desirable (e.g. an 11b-only ap with stronger
873 * signal than an 11g ap).
875 rssia = MIN(a->base.se_rssi, STA_RSSI_MAX);
876 rssib = MIN(b->base.se_rssi, STA_RSSI_MAX);
877 if (abs(rssib - rssia) < 5) {
878 /* best/max rate preferred if signal level close enough XXX */
879 maxa = maxrate(&a->base);
880 maxb = maxrate(&b->base);
883 /* XXX use freq for channel preference */
884 /* for now just prefer 5Ghz band to all other bands */
885 PREFER(IEEE80211_IS_CHAN_5GHZ(a->base.se_chan),
886 IEEE80211_IS_CHAN_5GHZ(b->base.se_chan), 1);
888 /* all things being equal, use signal level */
889 return a->base.se_rssi - b->base.se_rssi;
894 * Check rate set suitability and return the best supported rate.
895 * XXX inspect MCS for HT
898 check_rate(struct ieee80211vap *vap, const struct ieee80211_channel *chan,
899 const struct ieee80211_scan_entry *se)
901 const struct ieee80211_rateset *srs;
902 int i, j, nrs, r, okrate, badrate, fixedrate, ucastrate;
905 okrate = badrate = 0;
907 srs = ieee80211_get_suprates(vap->iv_ic, chan);
908 nrs = se->se_rates[1];
911 ucastrate = vap->iv_txparms[ieee80211_chan2mode(chan)].ucastrate;
912 fixedrate = IEEE80211_FIXED_RATE_NONE;
914 for (i = 0; i < nrs; i++) {
915 r = IEEE80211_RV(rs[i]);
918 * Check any fixed rate is included.
923 * Check against our supported rates.
925 for (j = 0; j < srs->rs_nrates; j++)
926 if (r == IEEE80211_RV(srs->rs_rates[j])) {
927 if (r > okrate) /* NB: track max */
932 if (j == srs->rs_nrates && (rs[i] & IEEE80211_RATE_BASIC)) {
934 * Don't try joining a BSS, if we don't support
935 * one of its basic rates.
941 if (rs == se->se_rates+2) {
942 /* scan xrates too; sort of an algol68-style for loop */
943 nrs = se->se_xrates[1];
944 rs = se->se_xrates+2;
949 if (okrate == 0 || ucastrate != fixedrate)
950 return badrate | IEEE80211_RATE_BASIC;
952 return IEEE80211_RV(okrate);
956 match_id(const uint8_t *ie, const uint8_t *val, int len)
958 return (ie[1] == len && memcmp(ie+2, val, len) == 0);
962 match_ssid(const uint8_t *ie,
963 int nssid, const struct ieee80211_scan_ssid ssids[])
967 for (i = 0; i < nssid; i++) {
968 if (match_id(ie, ssids[i].ssid, ssids[i].len))
974 #ifdef IEEE80211_SUPPORT_TDMA
976 tdma_isfull(const struct ieee80211_tdma_param *tdma)
980 slotcnt = tdma->tdma_slotcnt;
981 for (slot = slotcnt-1; slot >= 0; slot--)
982 if (isclr(tdma->tdma_inuse, slot))
986 #endif /* IEEE80211_SUPPORT_TDMA */
989 * Test a scan candidate for suitability/compatibility.
992 match_bss(struct ieee80211vap *vap,
993 const struct ieee80211_scan_state *ss, struct sta_entry *se0,
996 struct ieee80211com *ic = vap->iv_ic;
997 struct ieee80211_scan_entry *se = &se0->base;
1002 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, se->se_chan)))
1003 fail |= MATCH_CHANNEL;
1005 * NB: normally the desired mode is used to construct
1006 * the channel list, but it's possible for the scan
1007 * cache to include entries for stations outside this
1008 * list so we check the desired mode here to weed them
1011 if (vap->iv_des_mode != IEEE80211_MODE_AUTO &&
1012 (se->se_chan->ic_flags & IEEE80211_CHAN_ALLTURBO) !=
1013 chanflags[vap->iv_des_mode])
1014 fail |= MATCH_CHANNEL;
1015 if (vap->iv_opmode == IEEE80211_M_IBSS) {
1016 if ((se->se_capinfo & IEEE80211_CAPINFO_IBSS) == 0)
1017 fail |= MATCH_CAPINFO;
1018 #ifdef IEEE80211_SUPPORT_TDMA
1019 } else if (vap->iv_opmode == IEEE80211_M_AHDEMO) {
1021 * Adhoc demo network setup shouldn't really be scanning
1022 * but just in case skip stations operating in IBSS or
1025 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS))
1026 fail |= MATCH_CAPINFO;
1028 * TDMA operation cannot coexist with a normal 802.11 network;
1029 * skip if IBSS or ESS capabilities are marked and require
1030 * the beacon have a TDMA ie present.
1032 if (vap->iv_caps & IEEE80211_C_TDMA) {
1033 const struct ieee80211_tdma_param *tdma =
1034 (const struct ieee80211_tdma_param *)se->se_ies.tdma_ie;
1035 const struct ieee80211_tdma_state *ts = vap->iv_tdma;
1038 fail |= MATCH_TDMA_NOIE;
1039 else if (tdma->tdma_version != ts->tdma_version)
1040 fail |= MATCH_TDMA_VERSION;
1041 else if (tdma->tdma_slot != 0)
1042 fail |= MATCH_TDMA_NOTMASTER;
1043 else if (tdma_isfull(tdma))
1044 fail |= MATCH_TDMA_NOSLOT;
1046 else if (ieee80211_local_address(se->se_macaddr))
1047 fail |= MATCH_TDMA_LOCAL;
1050 #endif /* IEEE80211_SUPPORT_TDMA */
1051 #ifdef IEEE80211_SUPPORT_MESH
1052 } else if (vap->iv_opmode == IEEE80211_M_MBSS) {
1053 const struct ieee80211_mesh_state *ms = vap->iv_mesh;
1055 * Mesh nodes have IBSS & ESS bits in capinfo turned off
1056 * and two special ie's that must be present.
1058 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS))
1059 fail |= MATCH_CAPINFO;
1060 else if (se->se_meshid[0] != IEEE80211_ELEMID_MESHID)
1061 fail |= MATCH_MESH_NOID;
1062 else if (ms->ms_idlen != 0 &&
1063 match_id(se->se_meshid, ms->ms_id, ms->ms_idlen))
1064 fail |= MATCH_MESHID;
1067 if ((se->se_capinfo & IEEE80211_CAPINFO_ESS) == 0)
1068 fail |= MATCH_CAPINFO;
1070 * If 11d is enabled and we're attempting to join a bss
1071 * that advertises it's country code then compare our
1072 * current settings to what we fetched from the country ie.
1073 * If our country code is unspecified or different then do
1074 * not attempt to join the bss. We should have already
1075 * dispatched an event to user space that identifies the
1076 * new country code so our regdomain config should match.
1078 if ((IEEE80211_IS_CHAN_11D(se->se_chan) ||
1079 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) &&
1080 se->se_cc[0] != 0 &&
1081 (ic->ic_regdomain.country == CTRY_DEFAULT ||
1082 !isocmp(se->se_cc, ic->ic_regdomain.isocc)))
1085 if (vap->iv_flags & IEEE80211_F_PRIVACY) {
1086 if ((se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0)
1087 fail |= MATCH_PRIVACY;
1089 /* XXX does this mean privacy is supported or required? */
1090 if (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY)
1091 fail |= MATCH_PRIVACY;
1093 se0->se_flags &= ~STA_DEMOTE11B;
1094 rate = check_rate(vap, se->se_chan, se);
1095 if (rate & IEEE80211_RATE_BASIC) {
1098 * An 11b-only ap will give a rate mismatch if there is an
1099 * OFDM fixed tx rate for 11g. Try downgrading the channel
1100 * in the scan list to 11b and retry the rate check.
1102 if (IEEE80211_IS_CHAN_ANYG(se->se_chan)) {
1103 rate = check_rate(vap, demote11b(vap, se->se_chan), se);
1104 if ((rate & IEEE80211_RATE_BASIC) == 0) {
1105 fail &= ~MATCH_RATE;
1106 se0->se_flags |= STA_DEMOTE11B;
1109 } else if (rate < 2*24) {
1111 * This is an 11b-only ap. Check the desired mode in
1112 * case that needs to be honored (mode 11g filters out
1113 * 11b-only ap's). Otherwise force any 11g channel used
1114 * in scanning to be demoted.
1116 * NB: we cheat a bit here by looking at the max rate;
1117 * we could/should check the rates.
1119 if (!(vap->iv_des_mode == IEEE80211_MODE_AUTO ||
1120 vap->iv_des_mode == IEEE80211_MODE_11B))
1123 se0->se_flags |= STA_DEMOTE11B;
1125 if (ss->ss_nssid != 0 &&
1126 !match_ssid(se->se_ssid, ss->ss_nssid, ss->ss_ssid))
1128 if ((vap->iv_flags & IEEE80211_F_DESBSSID) &&
1129 !IEEE80211_ADDR_EQ(vap->iv_des_bssid, se->se_bssid))
1130 fail |= MATCH_BSSID;
1131 if (se0->se_fails >= STA_FAILS_MAX)
1132 fail |= MATCH_FAILS;
1133 if (se0->se_notseen >= STA_PURGE_SCANS)
1134 fail |= MATCH_NOTSEEN;
1135 if (se->se_rssi < STA_RSSI_MIN)
1137 #ifdef IEEE80211_DEBUG
1138 if (ieee80211_msg(vap, debug)) {
1140 fail & MATCH_FAILS ? '=' :
1141 fail & MATCH_NOTSEEN ? '^' :
1142 fail & MATCH_CC ? '$' :
1143 #ifdef IEEE80211_SUPPORT_TDMA
1144 fail & MATCH_TDMA_NOIE ? '&' :
1145 fail & MATCH_TDMA_VERSION ? 'v' :
1146 fail & MATCH_TDMA_NOTMASTER ? 's' :
1147 fail & MATCH_TDMA_NOSLOT ? 'f' :
1148 fail & MATCH_TDMA_LOCAL ? 'l' :
1150 fail & MATCH_MESH_NOID ? 'm' :
1151 fail ? '-' : '+', ether_sprintf(se->se_macaddr));
1152 printf(" %s%c", ether_sprintf(se->se_bssid),
1153 fail & MATCH_BSSID ? '!' : ' ');
1154 printf(" %3d%c", ieee80211_chan2ieee(ic, se->se_chan),
1155 fail & MATCH_CHANNEL ? '!' : ' ');
1156 printf(" %+4d%c", se->se_rssi, fail & MATCH_RSSI ? '!' : ' ');
1157 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2,
1158 fail & MATCH_RATE ? '!' : ' ');
1160 (se->se_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" :
1161 (se->se_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : "",
1162 fail & MATCH_CAPINFO ? '!' : ' ');
1164 (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) ?
1166 fail & MATCH_PRIVACY ? '!' : ' ');
1167 ieee80211_print_essid(se->se_ssid+2, se->se_ssid[1]);
1168 printf("%s\n", fail & (MATCH_SSID | MATCH_MESHID) ? "!" : "");
1175 sta_update_notseen(struct sta_table *st)
1177 struct sta_entry *se;
1179 IEEE80211_SCAN_TABLE_LOCK(st);
1180 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1182 * If seen the reset and don't bump the count;
1183 * otherwise bump the ``not seen'' count. Note
1184 * that this insures that stations for which we
1185 * see frames while not scanning but not during
1186 * this scan will not be penalized.
1193 IEEE80211_SCAN_TABLE_UNLOCK(st);
1197 sta_dec_fails(struct sta_table *st)
1199 struct sta_entry *se;
1201 IEEE80211_SCAN_TABLE_LOCK(st);
1202 TAILQ_FOREACH(se, &st->st_entry, se_list)
1205 IEEE80211_SCAN_TABLE_UNLOCK(st);
1208 static struct sta_entry *
1209 select_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, int debug)
1211 struct sta_table *st = ss->ss_priv;
1212 struct sta_entry *se, *selbs = NULL;
1214 IEEE80211_DPRINTF(vap, debug, " %s\n",
1215 "macaddr bssid chan rssi rate flag wep essid");
1216 IEEE80211_SCAN_TABLE_LOCK(st);
1217 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1218 ieee80211_ies_expand(&se->base.se_ies);
1219 if (match_bss(vap, ss, se, debug) == 0) {
1222 else if (sta_compare(se, selbs) > 0)
1226 IEEE80211_SCAN_TABLE_UNLOCK(st);
1232 * Pick an ap or ibss network to join or find a channel
1233 * to use to start an ibss network.
1236 sta_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1238 struct sta_table *st = ss->ss_priv;
1239 struct sta_entry *selbs;
1240 struct ieee80211_channel *chan;
1242 KASSERT(vap->iv_opmode == IEEE80211_M_STA,
1243 ("wrong mode %u", vap->iv_opmode));
1245 if (st->st_newscan) {
1246 sta_update_notseen(st);
1249 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1251 * Manual/background scan, don't select+join the
1252 * bss, just return. The scanning framework will
1253 * handle notification that this has completed.
1255 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1259 * Automatic sequencing; look for a candidate and
1260 * if found join the network.
1262 /* NB: unlocked read should be ok */
1263 if (TAILQ_FIRST(&st->st_entry) == NULL) {
1264 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1265 "%s: no scan candidate\n", __func__);
1266 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1270 * If nothing suitable was found decrement
1271 * the failure counts so entries will be
1272 * reconsidered the next time around. We
1273 * really want to do this only for sta's
1274 * where we've previously had some success.
1278 return 0; /* restart scan */
1280 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1281 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1282 return (selbs != NULL);
1285 chan = selbs->base.se_chan;
1286 if (selbs->se_flags & STA_DEMOTE11B)
1287 chan = demote11b(vap, chan);
1288 if (!ieee80211_sta_join(vap, chan, &selbs->base))
1290 return 1; /* terminate scan */
1294 * Lookup an entry in the scan cache. We assume we're
1295 * called from the bottom half or such that we don't need
1296 * to block the bottom half so that it's safe to return
1297 * a reference to an entry w/o holding the lock on the table.
1299 static struct sta_entry *
1300 sta_lookup(struct sta_table *st, const uint8_t macaddr[IEEE80211_ADDR_LEN])
1302 struct sta_entry *se;
1303 int hash = STA_HASH(macaddr);
1305 IEEE80211_SCAN_TABLE_LOCK(st);
1306 LIST_FOREACH(se, &st->st_hash[hash], se_hash)
1307 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr))
1309 IEEE80211_SCAN_TABLE_UNLOCK(st);
1311 return se; /* NB: unlocked */
1315 sta_roam_check(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1317 struct ieee80211com *ic = vap->iv_ic;
1318 struct ieee80211_node *ni = vap->iv_bss;
1319 struct sta_table *st = ss->ss_priv;
1320 enum ieee80211_phymode mode;
1321 struct sta_entry *se, *selbs;
1322 uint8_t roamRate, curRate, ucastRate;
1323 int8_t roamRssi, curRssi;
1325 se = sta_lookup(st, ni->ni_macaddr);
1327 /* XXX something is wrong */
1331 mode = ieee80211_chan2mode(ic->ic_bsschan);
1332 roamRate = vap->iv_roamparms[mode].rate;
1333 roamRssi = vap->iv_roamparms[mode].rssi;
1334 ucastRate = vap->iv_txparms[mode].ucastrate;
1335 /* NB: the most up to date rssi is in the node, not the scan cache */
1336 curRssi = ic->ic_node_getrssi(ni);
1337 if (ucastRate == IEEE80211_FIXED_RATE_NONE) {
1338 curRate = ni->ni_txrate;
1339 roamRate &= IEEE80211_RATE_VAL;
1340 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM,
1341 "%s: currssi %d currate %u roamrssi %d roamrate %u\n",
1342 __func__, curRssi, curRate, roamRssi, roamRate);
1344 curRate = roamRate; /* NB: insure compare below fails */
1345 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM,
1346 "%s: currssi %d roamrssi %d\n", __func__, curRssi, roamRssi);
1349 * Check if a new ap should be used and switch.
1350 * XXX deauth current ap
1352 if (curRate < roamRate || curRssi < roamRssi) {
1353 if (ieee80211_time_after(ticks, ic->ic_lastscan + vap->iv_scanvalid)) {
1355 * Scan cache contents are too old; force a scan now
1356 * if possible so we have current state to make a
1357 * decision with. We don't kick off a bg scan if
1358 * we're using dynamic turbo and boosted or if the
1360 * XXX force immediate switch on scan complete
1362 if (!IEEE80211_IS_CHAN_DTURBO(ic->ic_curchan) &&
1363 ((vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) ||
1364 ieee80211_time_after(ticks, ic->ic_lastdata + vap->iv_bgscanidle)))
1365 ieee80211_bg_scan(vap, 0);
1368 se->base.se_rssi = curRssi;
1369 selbs = select_bss(ss, vap, IEEE80211_MSG_ROAM);
1370 if (selbs != NULL && selbs != se) {
1371 struct ieee80211_channel *chan;
1373 IEEE80211_DPRINTF(vap,
1374 IEEE80211_MSG_ROAM | IEEE80211_MSG_DEBUG,
1375 "%s: ROAM: curRate %u, roamRate %u, "
1376 "curRssi %d, roamRssi %d\n", __func__,
1377 curRate, roamRate, curRssi, roamRssi);
1379 chan = selbs->base.se_chan;
1380 if (selbs->se_flags & STA_DEMOTE11B)
1381 chan = demote11b(vap, chan);
1382 (void) ieee80211_sta_join(vap, chan, &selbs->base);
1388 * Age entries in the scan cache.
1389 * XXX also do roaming since it's convenient
1392 sta_age(struct ieee80211_scan_state *ss)
1394 struct ieee80211vap *vap = ss->ss_vap;
1398 * If rate control is enabled check periodically to see if
1399 * we should roam from our current connection to one that
1400 * might be better. This only applies when we're operating
1401 * in sta mode and automatic roaming is set.
1403 * XXX repeater station
1404 * XXX do when !bgscan?
1406 KASSERT(vap->iv_opmode == IEEE80211_M_STA,
1407 ("wrong mode %u", vap->iv_opmode));
1408 if (vap->iv_roaming == IEEE80211_ROAMING_AUTO &&
1409 (vap->iv_flags & IEEE80211_F_BGSCAN) &&
1410 vap->iv_state >= IEEE80211_S_RUN)
1411 /* XXX vap is implicit */
1412 sta_roam_check(ss, vap);
1416 * Iterate over the entries in the scan cache, invoking
1417 * the callback function on each one.
1420 sta_iterate(struct ieee80211_scan_state *ss,
1421 ieee80211_scan_iter_func *f, void *arg)
1423 struct sta_table *st = ss->ss_priv;
1424 struct sta_entry *se;
1427 IEEE80211_SCAN_ITER_LOCK(st);
1428 gen = st->st_scaniter++;
1430 IEEE80211_SCAN_TABLE_LOCK(st);
1431 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1432 if (se->se_scangen != gen) {
1433 se->se_scangen = gen;
1434 /* update public state */
1435 se->base.se_age = ticks - se->se_lastupdate;
1436 IEEE80211_SCAN_TABLE_UNLOCK(st);
1437 (*f)(arg, &se->base);
1441 IEEE80211_SCAN_TABLE_UNLOCK(st);
1443 IEEE80211_SCAN_ITER_UNLOCK(st);
1447 sta_assoc_fail(struct ieee80211_scan_state *ss,
1448 const uint8_t macaddr[IEEE80211_ADDR_LEN], int reason)
1450 struct sta_table *st = ss->ss_priv;
1451 struct sta_entry *se;
1453 se = sta_lookup(st, macaddr);
1456 se->se_lastfail = ticks;
1457 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN,
1458 macaddr, "%s: reason %u fails %u",
1459 __func__, reason, se->se_fails);
1464 sta_assoc_success(struct ieee80211_scan_state *ss,
1465 const uint8_t macaddr[IEEE80211_ADDR_LEN])
1467 struct sta_table *st = ss->ss_priv;
1468 struct sta_entry *se;
1470 se = sta_lookup(st, macaddr);
1474 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN,
1475 macaddr, "%s: fails %u",
1476 __func__, se->se_fails);
1478 se->se_lastassoc = ticks;
1482 static const struct ieee80211_scanner sta_default = {
1483 .scan_name = "default",
1484 .scan_attach = sta_attach,
1485 .scan_detach = sta_detach,
1486 .scan_start = sta_start,
1487 .scan_restart = sta_restart,
1488 .scan_cancel = sta_cancel,
1489 .scan_end = sta_pick_bss,
1490 .scan_flush = sta_flush,
1491 .scan_add = sta_add,
1492 .scan_age = sta_age,
1493 .scan_iterate = sta_iterate,
1494 .scan_assoc_fail = sta_assoc_fail,
1495 .scan_assoc_success = sta_assoc_success,
1497 IEEE80211_SCANNER_ALG(sta, IEEE80211_M_STA, sta_default);
1500 * Adhoc mode-specific support.
1503 static const uint16_t adhocWorld[] = /* 36, 40, 44, 48 */
1504 { 5180, 5200, 5220, 5240 };
1505 static const uint16_t adhocFcc3[] = /* 36, 40, 44, 48 145, 149, 153, 157, 161, 165 */
1506 { 5180, 5200, 5220, 5240, 5725, 5745, 5765, 5785, 5805, 5825 };
1507 static const uint16_t adhocMkk[] = /* 34, 38, 42, 46 */
1508 { 5170, 5190, 5210, 5230 };
1509 static const uint16_t adhoc11b[] = /* 10, 11 */
1512 static const struct scanlist adhocScanTable[] = {
1513 { IEEE80211_MODE_11B, X(adhoc11b) },
1514 { IEEE80211_MODE_11A, X(adhocWorld) },
1515 { IEEE80211_MODE_11A, X(adhocFcc3) },
1516 { IEEE80211_MODE_11B, X(adhocMkk) },
1522 * Start an adhoc-mode scan by populating the channel list.
1525 adhoc_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1527 struct sta_table *st = ss->ss_priv;
1529 makescanlist(ss, vap, adhocScanTable);
1531 if (ss->ss_mindwell == 0)
1532 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */
1533 if (ss->ss_maxdwell == 0)
1534 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
1543 * Select a channel to start an adhoc network on.
1544 * The channel list was populated with appropriate
1545 * channels so select one that looks least occupied.
1547 static struct ieee80211_channel *
1548 adhoc_pick_channel(struct ieee80211_scan_state *ss, int flags)
1550 struct sta_table *st = ss->ss_priv;
1551 struct sta_entry *se;
1552 struct ieee80211_channel *c, *bestchan;
1553 int i, bestrssi, maxrssi;
1558 IEEE80211_SCAN_TABLE_LOCK(st);
1559 for (i = 0; i < ss->ss_last; i++) {
1560 c = ss->ss_chans[i];
1561 /* never consider a channel with radar */
1562 if (IEEE80211_IS_CHAN_RADAR(c))
1564 /* skip channels disallowed by regulatory settings */
1565 if (IEEE80211_IS_CHAN_NOADHOC(c))
1567 /* check channel attributes for band compatibility */
1568 if (flags != 0 && (c->ic_flags & flags) != flags)
1571 TAILQ_FOREACH(se, &st->st_entry, se_list) {
1572 if (se->base.se_chan != c)
1574 if (se->base.se_rssi > maxrssi)
1575 maxrssi = se->base.se_rssi;
1577 if (bestchan == NULL || maxrssi < bestrssi)
1580 IEEE80211_SCAN_TABLE_UNLOCK(st);
1586 * Pick an ibss network to join or find a channel
1587 * to use to start an ibss network.
1590 adhoc_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1592 struct sta_table *st = ss->ss_priv;
1593 struct sta_entry *selbs;
1594 struct ieee80211_channel *chan;
1595 struct ieee80211com *ic = vap->iv_ic;
1597 KASSERT(vap->iv_opmode == IEEE80211_M_IBSS ||
1598 vap->iv_opmode == IEEE80211_M_AHDEMO ||
1599 vap->iv_opmode == IEEE80211_M_MBSS,
1600 ("wrong opmode %u", vap->iv_opmode));
1602 if (st->st_newscan) {
1603 sta_update_notseen(st);
1606 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1608 * Manual/background scan, don't select+join the
1609 * bss, just return. The scanning framework will
1610 * handle notification that this has completed.
1612 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1616 * Automatic sequencing; look for a candidate and
1617 * if found join the network.
1619 /* NB: unlocked read should be ok */
1620 if (TAILQ_FIRST(&st->st_entry) == NULL) {
1621 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1622 "%s: no scan candidate\n", __func__);
1623 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1626 /* NB: never auto-start a tdma network for slot !0 */
1627 #ifdef IEEE80211_SUPPORT_TDMA
1628 if (vap->iv_des_nssid &&
1629 ((vap->iv_caps & IEEE80211_C_TDMA) == 0 ||
1630 ieee80211_tdma_getslot(vap) == 0)) {
1632 if (vap->iv_des_nssid) {
1635 * No existing adhoc network to join and we have
1636 * an ssid; start one up. If no channel was
1637 * specified, try to select a channel.
1639 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC ||
1640 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
1641 chan = adhoc_pick_channel(ss, 0);
1643 chan = vap->iv_des_chan;
1646 * Create a HT capable IBSS; the per-node
1647 * probe request/response will result in
1648 * "correct" rate control capabilities being
1651 chan = ieee80211_ht_adjust_channel(ic,
1652 chan, vap->iv_flags_ht);
1653 chan = ieee80211_vht_adjust_channel(ic,
1654 chan, vap->iv_flags_vht);
1655 ieee80211_create_ibss(vap, chan);
1660 * If nothing suitable was found decrement
1661 * the failure counts so entries will be
1662 * reconsidered the next time around. We
1663 * really want to do this only for sta's
1664 * where we've previously had some success.
1668 return 0; /* restart scan */
1670 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1671 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1672 return (selbs != NULL);
1675 chan = selbs->base.se_chan;
1676 if (selbs->se_flags & STA_DEMOTE11B)
1677 chan = demote11b(vap, chan);
1679 * If HT is available, make it a possibility here.
1680 * The intent is to enable HT20/HT40 when joining a non-HT
1681 * IBSS node; we can then advertise HT IEs and speak HT
1682 * to any subsequent nodes that support it.
1684 chan = ieee80211_ht_adjust_channel(ic,
1685 chan, vap->iv_flags_ht);
1686 chan = ieee80211_vht_adjust_channel(ic,
1687 chan, vap->iv_flags_vht);
1688 if (!ieee80211_sta_join(vap, chan, &selbs->base))
1690 return 1; /* terminate scan */
1694 * Age entries in the scan cache.
1697 adhoc_age(struct ieee80211_scan_state *ss)
1699 struct sta_table *st = ss->ss_priv;
1700 struct sta_entry *se, *next;
1702 IEEE80211_SCAN_TABLE_LOCK(st);
1703 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) {
1704 if (se->se_notseen > STA_PURGE_SCANS) {
1705 TAILQ_REMOVE(&st->st_entry, se, se_list);
1706 LIST_REMOVE(se, se_hash);
1707 ieee80211_ies_cleanup(&se->base.se_ies);
1708 IEEE80211_FREE(se, M_80211_SCAN);
1711 IEEE80211_SCAN_TABLE_UNLOCK(st);
1714 static const struct ieee80211_scanner adhoc_default = {
1715 .scan_name = "default",
1716 .scan_attach = sta_attach,
1717 .scan_detach = sta_detach,
1718 .scan_start = adhoc_start,
1719 .scan_restart = sta_restart,
1720 .scan_cancel = sta_cancel,
1721 .scan_end = adhoc_pick_bss,
1722 .scan_flush = sta_flush,
1723 .scan_pickchan = adhoc_pick_channel,
1724 .scan_add = sta_add,
1725 .scan_age = adhoc_age,
1726 .scan_iterate = sta_iterate,
1727 .scan_assoc_fail = sta_assoc_fail,
1728 .scan_assoc_success = sta_assoc_success,
1730 IEEE80211_SCANNER_ALG(ibss, IEEE80211_M_IBSS, adhoc_default);
1731 IEEE80211_SCANNER_ALG(ahdemo, IEEE80211_M_AHDEMO, adhoc_default);
1734 ap_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1736 struct sta_table *st = ss->ss_priv;
1738 makescanlist(ss, vap, staScanTable);
1740 if (ss->ss_mindwell == 0)
1741 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */
1742 if (ss->ss_maxdwell == 0)
1743 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */
1752 * Cancel an ongoing scan.
1755 ap_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1761 * Pick a quiet channel to use for ap operation.
1763 static struct ieee80211_channel *
1764 ap_pick_channel(struct ieee80211_scan_state *ss, int flags)
1766 struct sta_table *st = ss->ss_priv;
1767 struct ieee80211_channel *bestchan = NULL;
1770 /* XXX select channel more intelligently, e.g. channel spread, power */
1771 /* NB: use scan list order to preserve channel preference */
1772 for (i = 0; i < ss->ss_last; i++) {
1773 struct ieee80211_channel *chan = ss->ss_chans[i];
1775 * If the channel is unoccupied the max rssi
1776 * should be zero; just take it. Otherwise
1777 * track the channel with the lowest rssi and
1778 * use that when all channels appear occupied.
1780 if (IEEE80211_IS_CHAN_RADAR(chan))
1782 if (IEEE80211_IS_CHAN_NOHOSTAP(chan))
1784 /* check channel attributes for band compatibility */
1785 if (flags != 0 && (chan->ic_flags & flags) != flags)
1787 KASSERT(sizeof(chan->ic_ieee) == 1, ("ic_chan size"));
1788 /* XXX channel have interference */
1789 if (st->st_maxrssi[chan->ic_ieee] == 0) {
1790 /* XXX use other considerations */
1793 if (bestchan == NULL ||
1794 st->st_maxrssi[chan->ic_ieee] < st->st_maxrssi[bestchan->ic_ieee])
1801 * Pick a quiet channel to use for ap operation.
1804 ap_end(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1806 struct ieee80211com *ic = vap->iv_ic;
1807 struct ieee80211_channel *bestchan, *chan;
1809 KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP,
1810 ("wrong opmode %u", vap->iv_opmode));
1811 bestchan = ap_pick_channel(ss, 0);
1812 if (bestchan == NULL) {
1813 /* no suitable channel, should not happen */
1814 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1815 "%s: no suitable channel! (should not happen)\n", __func__);
1816 /* XXX print something? */
1817 return 0; /* restart scan */
1820 * If this is a dynamic turbo channel, start with the unboosted one.
1822 if (IEEE80211_IS_CHAN_TURBO(bestchan)) {
1823 bestchan = ieee80211_find_channel(ic, bestchan->ic_freq,
1824 bestchan->ic_flags & ~IEEE80211_CHAN_TURBO);
1825 if (bestchan == NULL) {
1826 /* should never happen ?? */
1830 if (ss->ss_flags & (IEEE80211_SCAN_NOPICK | IEEE80211_SCAN_NOJOIN)) {
1832 * Manual/background scan, don't select+join the
1833 * bss, just return. The scanning framework will
1834 * handle notification that this has completed.
1836 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1839 chan = ieee80211_ht_adjust_channel(ic, bestchan, vap->iv_flags_ht);
1840 chan = ieee80211_vht_adjust_channel(ic, chan, vap->iv_flags_vht);
1841 ieee80211_create_ibss(vap, chan);
1846 static const struct ieee80211_scanner ap_default = {
1847 .scan_name = "default",
1848 .scan_attach = sta_attach,
1849 .scan_detach = sta_detach,
1850 .scan_start = ap_start,
1851 .scan_restart = sta_restart,
1852 .scan_cancel = ap_cancel,
1854 .scan_flush = sta_flush,
1855 .scan_pickchan = ap_pick_channel,
1856 .scan_add = sta_add,
1857 .scan_age = adhoc_age,
1858 .scan_iterate = sta_iterate,
1859 .scan_assoc_success = sta_assoc_success,
1860 .scan_assoc_fail = sta_assoc_fail,
1862 IEEE80211_SCANNER_ALG(ap, IEEE80211_M_HOSTAP, ap_default);
1864 #ifdef IEEE80211_SUPPORT_MESH
1866 * Pick an mbss network to join or find a channel
1867 * to use to start an mbss network.
1870 mesh_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1872 struct sta_table *st = ss->ss_priv;
1873 struct ieee80211_mesh_state *ms = vap->iv_mesh;
1874 struct sta_entry *selbs;
1875 struct ieee80211_channel *chan;
1877 KASSERT(vap->iv_opmode == IEEE80211_M_MBSS,
1878 ("wrong opmode %u", vap->iv_opmode));
1880 if (st->st_newscan) {
1881 sta_update_notseen(st);
1884 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1886 * Manual/background scan, don't select+join the
1887 * bss, just return. The scanning framework will
1888 * handle notification that this has completed.
1890 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1894 * Automatic sequencing; look for a candidate and
1895 * if found join the network.
1897 /* NB: unlocked read should be ok */
1898 if (TAILQ_FIRST(&st->st_entry) == NULL) {
1899 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1900 "%s: no scan candidate\n", __func__);
1901 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1904 if (ms->ms_idlen != 0) {
1906 * No existing mbss network to join and we have
1907 * a meshid; start one up. If no channel was
1908 * specified, try to select a channel.
1910 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC ||
1911 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
1912 struct ieee80211com *ic = vap->iv_ic;
1915 chan = adhoc_pick_channel(ss, 0);
1917 chan = ieee80211_ht_adjust_channel(ic,
1918 chan, vap->iv_flags_ht);
1919 chan = ieee80211_vht_adjust_channel(ic,
1920 chan, vap->iv_flags_vht);
1923 chan = vap->iv_des_chan;
1925 ieee80211_create_ibss(vap, chan);
1930 * If nothing suitable was found decrement
1931 * the failure counts so entries will be
1932 * reconsidered the next time around. We
1933 * really want to do this only for sta's
1934 * where we've previously had some success.
1938 return 0; /* restart scan */
1940 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1941 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1942 return (selbs != NULL);
1945 chan = selbs->base.se_chan;
1946 if (selbs->se_flags & STA_DEMOTE11B)
1947 chan = demote11b(vap, chan);
1948 if (!ieee80211_sta_join(vap, chan, &selbs->base))
1950 return 1; /* terminate scan */
1953 static const struct ieee80211_scanner mesh_default = {
1954 .scan_name = "default",
1955 .scan_attach = sta_attach,
1956 .scan_detach = sta_detach,
1957 .scan_start = adhoc_start,
1958 .scan_restart = sta_restart,
1959 .scan_cancel = sta_cancel,
1960 .scan_end = mesh_pick_bss,
1961 .scan_flush = sta_flush,
1962 .scan_pickchan = adhoc_pick_channel,
1963 .scan_add = sta_add,
1964 .scan_age = adhoc_age,
1965 .scan_iterate = sta_iterate,
1966 .scan_assoc_fail = sta_assoc_fail,
1967 .scan_assoc_success = sta_assoc_success,
1969 IEEE80211_SCANNER_ALG(mesh, IEEE80211_M_MBSS, mesh_default);
1970 #endif /* IEEE80211_SUPPORT_MESH */