2 * Copyright (c) 2002-2008 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 scanning support.
34 #include <sys/param.h>
35 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/condvar.h>
40 #include <sys/socket.h>
43 #include <net/if_var.h>
44 #include <net/if_media.h>
45 #include <net/ethernet.h>
47 #include <net80211/ieee80211_var.h>
49 #include <net80211/ieee80211_scan_sw.h>
54 struct ieee80211_scan_state base; /* public state */
56 u_int ss_iflags; /* flags used internally */
57 #define ISCAN_MINDWELL 0x0001 /* min dwell time reached */
58 #define ISCAN_DISCARD 0x0002 /* discard rx'd frames */
59 #define ISCAN_CANCEL 0x0004 /* cancel current scan */
60 #define ISCAN_ABORT 0x0008 /* end the scan immediately */
61 unsigned long ss_chanmindwell; /* min dwell on curchan */
62 unsigned long ss_scanend; /* time scan must stop */
63 u_int ss_duration; /* duration for next scan */
64 struct task ss_scan_task; /* scan execution */
65 struct cv ss_scan_cv; /* scan signal */
66 struct callout ss_scan_timer; /* scan timer */
68 #define SCAN_PRIVATE(ss) ((struct scan_state *) ss)
71 * Amount of time to go off-channel during a background
72 * scan. This value should be large enough to catch most
73 * ap's but short enough that we can return on-channel
74 * before our listen interval expires.
77 * XXX check against configured listen interval
79 #define IEEE80211_SCAN_OFFCHANNEL msecs_to_ticks(150)
82 * Roaming-related defaults. RSSI thresholds are as returned by the
83 * driver (.5dBm). Transmit rate thresholds are IEEE rate codes (i.e
87 #define ROAM_RSSI_11A_DEFAULT 14 /* 11a bss */
88 #define ROAM_RSSI_11B_DEFAULT 14 /* 11b bss */
89 #define ROAM_RSSI_11BONLY_DEFAULT 14 /* 11b-only bss */
90 /* transmit rate thresholds */
91 #define ROAM_RATE_11A_DEFAULT 2*12 /* 11a bss */
92 #define ROAM_RATE_11B_DEFAULT 2*5 /* 11b bss */
93 #define ROAM_RATE_11BONLY_DEFAULT 2*1 /* 11b-only bss */
94 #define ROAM_RATE_HALF_DEFAULT 2*6 /* half-width 11a/g bss */
95 #define ROAM_RATE_QUARTER_DEFAULT 2*3 /* quarter-width 11a/g bss */
96 #define ROAM_MCS_11N_DEFAULT (1 | IEEE80211_RATE_MCS) /* 11n bss */
98 static void scan_curchan(struct ieee80211_scan_state *, unsigned long);
99 static void scan_mindwell(struct ieee80211_scan_state *);
100 static void scan_signal(void *);
101 static void scan_task(void *, int);
103 MALLOC_DEFINE(M_80211_SCAN, "80211scan", "802.11 scan state");
106 ieee80211_swscan_detach(struct ieee80211com *ic)
108 struct ieee80211_scan_state *ss = ic->ic_scan;
112 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_ABORT;
114 IEEE80211_UNLOCK(ic);
115 ieee80211_draintask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
116 callout_drain(&SCAN_PRIVATE(ss)->ss_scan_timer);
117 KASSERT((ic->ic_flags & IEEE80211_F_SCAN) == 0,
118 ("scan still running"));
121 * For now, do the ss_ops detach here rather
122 * than ieee80211_scan_detach().
124 * I'll figure out how to cleanly split things up
127 if (ss->ss_ops != NULL) {
128 ss->ss_ops->scan_detach(ss);
132 IEEE80211_FREE(SCAN_PRIVATE(ss), M_80211_SCAN);
137 ieee80211_swscan_vattach(struct ieee80211vap *vap)
139 /* nothing to do for now */
141 * TODO: all of the vap scan calls should be methods!
147 ieee80211_swscan_vdetach(struct ieee80211vap *vap)
149 struct ieee80211com *ic = vap->iv_ic;
150 struct ieee80211_scan_state *ss;
152 IEEE80211_LOCK_ASSERT(ic);
154 if (ss != NULL && ss->ss_vap == vap) {
155 if (ic->ic_flags & IEEE80211_F_SCAN) {
156 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_ABORT;
163 ieee80211_swscan_set_scan_duration(struct ieee80211vap *vap, u_int duration)
165 struct ieee80211com *ic = vap->iv_ic;
166 struct ieee80211_scan_state *ss = ic->ic_scan;
168 IEEE80211_LOCK_ASSERT(ic);
170 /* NB: flush frames rx'd before 1st channel change */
171 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
172 SCAN_PRIVATE(ss)->ss_duration = duration;
176 * Start a scan unless one is already going.
179 ieee80211_swscan_start_scan_locked(const struct ieee80211_scanner *scan,
180 struct ieee80211vap *vap, int flags, u_int duration,
181 u_int mindwell, u_int maxdwell,
182 u_int nssid, const struct ieee80211_scan_ssid ssids[])
184 struct ieee80211com *ic = vap->iv_ic;
185 struct ieee80211_scan_state *ss = ic->ic_scan;
187 IEEE80211_LOCK_ASSERT(ic);
189 if (ic->ic_flags & IEEE80211_F_CSAPENDING) {
190 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
191 "%s: scan inhibited by pending channel change\n", __func__);
192 } else if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
193 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
194 "%s: %s scan, duration %u mindwell %u maxdwell %u, desired mode %s, %s%s%s%s%s%s\n"
196 , flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"
197 , duration, mindwell, maxdwell
198 , ieee80211_phymode_name[vap->iv_des_mode]
199 , flags & IEEE80211_SCAN_FLUSH ? "flush" : "append"
200 , flags & IEEE80211_SCAN_NOPICK ? ", nopick" : ""
201 , flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : ""
202 , flags & IEEE80211_SCAN_NOBCAST ? ", nobcast" : ""
203 , flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : ""
204 , flags & IEEE80211_SCAN_ONCE ? ", once" : ""
207 ieee80211_scan_update_locked(vap, scan);
208 if (ss->ss_ops != NULL) {
209 if ((flags & IEEE80211_SCAN_NOSSID) == 0)
210 ieee80211_scan_copy_ssid(vap, ss, nssid, ssids);
212 /* NB: top 4 bits for internal use */
213 ss->ss_flags = flags & 0xfff;
214 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
215 vap->iv_stats.is_scan_active++;
217 vap->iv_stats.is_scan_passive++;
218 if (flags & IEEE80211_SCAN_FLUSH)
219 ss->ss_ops->scan_flush(ss);
220 if (flags & IEEE80211_SCAN_BGSCAN)
221 ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN;
223 /* Set duration for this particular scan */
224 ieee80211_swscan_set_scan_duration(vap, duration);
227 ss->ss_mindwell = mindwell;
228 ss->ss_maxdwell = maxdwell;
229 /* NB: scan_start must be before the scan runtask */
230 ss->ss_ops->scan_start(ss, vap);
231 #ifdef IEEE80211_DEBUG
232 if (ieee80211_msg_scan(vap))
233 ieee80211_scan_dump(ss);
234 #endif /* IEEE80211_DEBUG */
235 ic->ic_flags |= IEEE80211_F_SCAN;
237 /* Start scan task */
238 ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
242 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
243 "%s: %s scan already in progress\n", __func__,
244 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
251 * Start a scan unless one is already going.
253 * Called without the comlock held; grab the comlock as appropriate.
256 ieee80211_swscan_start_scan(const struct ieee80211_scanner *scan,
257 struct ieee80211vap *vap, int flags,
258 u_int duration, u_int mindwell, u_int maxdwell,
259 u_int nssid, const struct ieee80211_scan_ssid ssids[])
261 struct ieee80211com *ic = vap->iv_ic;
264 IEEE80211_UNLOCK_ASSERT(ic);
267 result = ieee80211_swscan_start_scan_locked(scan, vap, flags, duration,
268 mindwell, maxdwell, nssid, ssids);
269 IEEE80211_UNLOCK(ic);
275 * Check the scan cache for an ap/channel to use; if that
276 * fails then kick off a new scan.
278 * Called with the comlock held.
280 * XXX TODO: split out!
283 ieee80211_swscan_check_scan(const struct ieee80211_scanner *scan,
284 struct ieee80211vap *vap, int flags,
285 u_int duration, u_int mindwell, u_int maxdwell,
286 u_int nssid, const struct ieee80211_scan_ssid ssids[])
288 struct ieee80211com *ic = vap->iv_ic;
289 struct ieee80211_scan_state *ss = ic->ic_scan;
292 IEEE80211_LOCK_ASSERT(ic);
294 if (ss->ss_ops != NULL) {
295 /* XXX verify ss_ops matches vap->iv_opmode */
296 if ((flags & IEEE80211_SCAN_NOSSID) == 0) {
298 * Update the ssid list and mark flags so if
299 * we call start_scan it doesn't duplicate work.
301 ieee80211_scan_copy_ssid(vap, ss, nssid, ssids);
302 flags |= IEEE80211_SCAN_NOSSID;
304 if ((ic->ic_flags & IEEE80211_F_SCAN) == 0 &&
305 (flags & IEEE80211_SCAN_FLUSH) == 0 &&
306 time_before(ticks, ic->ic_lastscan + vap->iv_scanvalid)) {
308 * We're not currently scanning and the cache is
309 * deemed hot enough to consult. Lock out others
310 * by marking IEEE80211_F_SCAN while we decide if
311 * something is already in the scan cache we can
312 * use. Also discard any frames that might come
313 * in while temporarily marked as scanning.
315 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
316 ic->ic_flags |= IEEE80211_F_SCAN;
318 /* NB: need to use supplied flags in check */
319 ss->ss_flags = flags & 0xff;
320 result = ss->ss_ops->scan_end(ss, vap);
322 ic->ic_flags &= ~IEEE80211_F_SCAN;
323 SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_DISCARD;
325 ieee80211_notify_scan_done(vap);
330 result = ieee80211_swscan_start_scan_locked(scan, vap, flags, duration,
331 mindwell, maxdwell, nssid, ssids);
337 * Restart a previous scan. If the previous scan completed
338 * then we start again using the existing channel list.
341 ieee80211_swscan_bg_scan(const struct ieee80211_scanner *scan,
342 struct ieee80211vap *vap, int flags)
344 struct ieee80211com *ic = vap->iv_ic;
345 struct ieee80211_scan_state *ss = ic->ic_scan;
347 /* XXX assert unlocked? */
348 // IEEE80211_UNLOCK_ASSERT(ic);
351 if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
354 * Go off-channel for a fixed interval that is large
355 * enough to catch most ap's but short enough that
356 * we can return on-channel before our listen interval
359 duration = IEEE80211_SCAN_OFFCHANNEL;
361 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
362 "%s: %s scan, ticks %u duration %lu\n", __func__,
363 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive",
366 ieee80211_scan_update_locked(vap, scan);
367 if (ss->ss_ops != NULL) {
370 * A background scan does not select a new sta; it
371 * just refreshes the scan cache. Also, indicate
372 * the scan logic should follow the beacon schedule:
373 * we go off-channel and scan for a while, then
374 * return to the bss channel to receive a beacon,
375 * then go off-channel again. All during this time
376 * we notify the ap we're in power save mode. When
377 * the scan is complete we leave power save mode.
378 * If any beacon indicates there are frames pending
379 * for us then we drop out of power save mode
380 * (and background scan) automatically by way of the
381 * usual sta power save logic.
383 ss->ss_flags |= IEEE80211_SCAN_NOPICK
384 | IEEE80211_SCAN_BGSCAN
387 /* if previous scan completed, restart */
388 if (ss->ss_next >= ss->ss_last) {
389 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
390 vap->iv_stats.is_scan_active++;
392 vap->iv_stats.is_scan_passive++;
394 * NB: beware of the scan cache being flushed;
395 * if the channel list is empty use the
396 * scan_start method to populate it.
399 if (ss->ss_last != 0)
400 ss->ss_ops->scan_restart(ss, vap);
402 ss->ss_ops->scan_start(ss, vap);
403 #ifdef IEEE80211_DEBUG
404 if (ieee80211_msg_scan(vap))
405 ieee80211_scan_dump(ss);
406 #endif /* IEEE80211_DEBUG */
409 ieee80211_swscan_set_scan_duration(vap, duration);
410 ss->ss_maxdwell = duration;
411 ic->ic_flags |= IEEE80211_F_SCAN;
412 ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN;
413 ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
418 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
419 "%s: %s scan already in progress\n", __func__,
420 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
422 IEEE80211_UNLOCK(ic);
424 /* NB: racey, does it matter? */
425 return (ic->ic_flags & IEEE80211_F_SCAN);
429 * Cancel any scan currently going on for the specified vap.
432 ieee80211_swscan_cancel_scan(struct ieee80211vap *vap)
434 struct ieee80211com *ic = vap->iv_ic;
435 struct ieee80211_scan_state *ss = ic->ic_scan;
438 if ((ic->ic_flags & IEEE80211_F_SCAN) &&
440 (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0) {
441 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
442 "%s: cancel %s scan\n", __func__,
443 ss->ss_flags & IEEE80211_SCAN_ACTIVE ?
444 "active" : "passive");
446 /* clear bg scan NOPICK and mark cancel request */
447 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
448 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_CANCEL;
449 /* wake up the scan task */
452 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
453 "%s: called; F_SCAN=%d, vap=%s, CANCEL=%d\n",
455 !! (ic->ic_flags & IEEE80211_F_SCAN),
456 (ss->ss_vap == vap ? "match" : "nomatch"),
457 !! (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL));
459 IEEE80211_UNLOCK(ic);
463 * Cancel any scan currently going on.
466 ieee80211_swscan_cancel_anyscan(struct ieee80211vap *vap)
468 struct ieee80211com *ic = vap->iv_ic;
469 struct ieee80211_scan_state *ss = ic->ic_scan;
472 if ((ic->ic_flags & IEEE80211_F_SCAN) &&
473 (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0) {
474 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
475 "%s: cancel %s scan\n", __func__,
476 ss->ss_flags & IEEE80211_SCAN_ACTIVE ?
477 "active" : "passive");
479 /* clear bg scan NOPICK and mark cancel request */
480 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
481 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_CANCEL;
482 /* wake up the scan task */
485 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
486 "%s: called; F_SCAN=%d, vap=%s, CANCEL=%d\n",
488 !! (ic->ic_flags & IEEE80211_F_SCAN),
489 (ss->ss_vap == vap ? "match" : "nomatch"),
490 !! (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL));
492 IEEE80211_UNLOCK(ic);
496 * Public access to scan_next for drivers that manage
497 * scanning themselves (e.g. for firmware-based devices).
500 ieee80211_swscan_scan_next(struct ieee80211vap *vap)
502 struct ieee80211com *ic = vap->iv_ic;
503 struct ieee80211_scan_state *ss = ic->ic_scan;
505 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: called\n", __func__);
507 /* wake up the scan task */
510 IEEE80211_UNLOCK(ic);
514 * Public access to scan_next for drivers that are not able to scan single
515 * channels (e.g. for firmware-based devices).
518 ieee80211_swscan_scan_done(struct ieee80211vap *vap)
520 struct ieee80211com *ic = vap->iv_ic;
521 struct ieee80211_scan_state *ss;
523 IEEE80211_LOCK_ASSERT(ic);
530 * Probe the curent channel, if allowed, while scanning.
531 * If the channel is not marked passive-only then send
532 * a probe request immediately. Otherwise mark state and
533 * listen for beacons on the channel; if we receive something
534 * then we'll transmit a probe request.
537 ieee80211_swscan_probe_curchan(struct ieee80211vap *vap, int force)
539 struct ieee80211com *ic = vap->iv_ic;
540 struct ieee80211_scan_state *ss = ic->ic_scan;
541 struct ifnet *ifp = vap->iv_ifp;
545 * Send directed probe requests followed by any
546 * broadcast probe request.
547 * XXX remove dependence on ic/vap->iv_bss
549 for (i = 0; i < ss->ss_nssid; i++)
550 ieee80211_send_probereq(vap->iv_bss,
551 vap->iv_myaddr, ifp->if_broadcastaddr,
552 ifp->if_broadcastaddr,
553 ss->ss_ssid[i].ssid, ss->ss_ssid[i].len);
554 if ((ss->ss_flags & IEEE80211_SCAN_NOBCAST) == 0)
555 ieee80211_send_probereq(vap->iv_bss,
556 vap->iv_myaddr, ifp->if_broadcastaddr,
557 ifp->if_broadcastaddr,
562 * Scan curchan. If this is an active scan and the channel
563 * is not marked passive then send probe request frame(s).
564 * Arrange for the channel change after maxdwell ticks.
567 scan_curchan(struct ieee80211_scan_state *ss, unsigned long maxdwell)
569 struct ieee80211vap *vap = ss->ss_vap;
571 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
572 "%s: calling; maxdwell=%lu\n",
575 IEEE80211_LOCK(vap->iv_ic);
576 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
577 ieee80211_probe_curchan(vap, 0);
578 callout_reset(&SCAN_PRIVATE(ss)->ss_scan_timer,
579 maxdwell, scan_signal, ss);
580 IEEE80211_UNLOCK(vap->iv_ic);
584 scan_signal(void *arg)
586 struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg;
588 IEEE80211_LOCK_ASSERT(ss->ss_ic);
589 cv_signal(&SCAN_PRIVATE(ss)->ss_scan_cv);
593 * Handle mindwell requirements completed; initiate a channel
594 * change to the next channel asap.
597 scan_mindwell(struct ieee80211_scan_state *ss)
599 struct ieee80211com *ic = ss->ss_ic;
601 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, "%s: called\n", __func__);
605 IEEE80211_UNLOCK(ic);
609 scan_task(void *arg, int pending)
611 #define ISCAN_REP (ISCAN_MINDWELL | ISCAN_DISCARD)
612 struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg;
613 struct ieee80211vap *vap = ss->ss_vap;
614 struct ieee80211com *ic = ss->ss_ic;
615 struct ieee80211_channel *chan;
616 unsigned long maxdwell, scanend;
620 if (vap == NULL || (ic->ic_flags & IEEE80211_F_SCAN) == 0 ||
621 (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT)) {
622 /* Cancelled before we started */
626 if (ss->ss_next == ss->ss_last) {
627 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
628 "%s: no channels to scan\n", __func__);
633 if (vap->iv_opmode == IEEE80211_M_STA &&
634 vap->iv_state == IEEE80211_S_RUN) {
635 if ((vap->iv_bss->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) {
636 /* Enable station power save mode */
637 vap->iv_sta_ps(vap, 1);
639 * Use an 1ms delay so the null data frame has a chance
641 * XXX Should use M_TXCB mechanism to eliminate this.
643 cv_timedwait(&SCAN_PRIVATE(ss)->ss_scan_cv,
644 IEEE80211_LOCK_OBJ(ic), hz / 1000);
645 if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT)
650 scanend = ticks + SCAN_PRIVATE(ss)->ss_duration;
652 /* XXX scan state can change! Re-validate scan state! */
654 IEEE80211_UNLOCK(ic);
655 ic->ic_scan_start(ic); /* notify driver */
660 scandone = (ss->ss_next >= ss->ss_last) ||
661 (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) != 0;
663 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
664 "%s: loop start; scandone=%d\n",
668 if (scandone || (ss->ss_flags & IEEE80211_SCAN_GOTPICK) ||
669 (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT) ||
670 time_after(ticks + ss->ss_mindwell, scanend))
673 chan = ss->ss_chans[ss->ss_next++];
676 * Watch for truncation due to the scan end time.
678 if (time_after(ticks + ss->ss_maxdwell, scanend))
679 maxdwell = scanend - ticks;
681 maxdwell = ss->ss_maxdwell;
683 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
684 "%s: chan %3d%c -> %3d%c [%s, dwell min %lums max %lums]\n",
686 ieee80211_chan2ieee(ic, ic->ic_curchan),
687 ieee80211_channel_type_char(ic->ic_curchan),
688 ieee80211_chan2ieee(ic, chan),
689 ieee80211_channel_type_char(chan),
690 (ss->ss_flags & IEEE80211_SCAN_ACTIVE) &&
691 (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0 ?
692 "active" : "passive",
693 ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(maxdwell));
696 * Potentially change channel and phy mode.
698 ic->ic_curchan = chan;
699 ic->ic_rt = ieee80211_get_ratetable(chan);
700 IEEE80211_UNLOCK(ic);
702 * Perform the channel change and scan unlocked so the driver
703 * may sleep. Once set_channel returns the hardware has
704 * completed the channel change.
706 ic->ic_set_channel(ic);
707 ieee80211_radiotap_chan_change(ic);
710 * Scan curchan. Drivers for "intelligent hardware"
711 * override ic_scan_curchan to tell the device to do
712 * the work. Otherwise we manage the work outselves;
713 * sending a probe request (as needed), and arming the
714 * timeout to switch channels after maxdwell ticks.
716 * scan_curchan should only pause for the time required to
717 * prepare/initiate the hardware for the scan (if at all), the
718 * below condvar is used to sleep for the channels dwell time
719 * and allows it to be signalled for abort.
721 ic->ic_scan_curchan(ss, maxdwell);
724 /* XXX scan state can change! Re-validate scan state! */
726 SCAN_PRIVATE(ss)->ss_chanmindwell = ticks + ss->ss_mindwell;
727 /* clear mindwell lock and initial channel change flush */
728 SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_REP;
730 if ((SCAN_PRIVATE(ss)->ss_iflags & (ISCAN_CANCEL|ISCAN_ABORT)))
733 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: waiting\n", __func__);
734 /* Wait to be signalled to scan the next channel */
735 cv_wait(&SCAN_PRIVATE(ss)->ss_scan_cv, IEEE80211_LOCK_OBJ(ic));
738 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: out\n", __func__);
740 if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT)
743 IEEE80211_UNLOCK(ic);
744 ic->ic_scan_end(ic); /* notify driver */
746 /* XXX scan state can change! Re-validate scan state! */
749 * Since a cancellation may have occured during one of the
750 * driver calls (whilst unlocked), update scandone.
753 ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) != 0)) {
755 if_printf(vap->iv_ifp,
756 "%s: OOPS! scan cancelled during driver call (1)!\n",
762 * Record scan complete time. Note that we also do
763 * this when canceled so any background scan will
764 * not be restarted for a while.
767 ic->ic_lastscan = ticks;
768 /* return to the bss channel */
769 if (ic->ic_bsschan != IEEE80211_CHAN_ANYC &&
770 ic->ic_curchan != ic->ic_bsschan) {
771 ieee80211_setupcurchan(ic, ic->ic_bsschan);
772 IEEE80211_UNLOCK(ic);
773 ic->ic_set_channel(ic);
774 ieee80211_radiotap_chan_change(ic);
777 /* clear internal flags and any indication of a pick */
778 SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_REP;
779 ss->ss_flags &= ~IEEE80211_SCAN_GOTPICK;
782 * If not canceled and scan completed, do post-processing.
783 * If the callback function returns 0, then it wants to
784 * continue/restart scanning. Unfortunately we needed to
785 * notify the driver to end the scan above to avoid having
786 * rx frames alter the scan candidate list.
788 if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0 &&
789 !ss->ss_ops->scan_end(ss, vap) &&
790 (ss->ss_flags & IEEE80211_SCAN_ONCE) == 0 &&
791 time_before(ticks + ss->ss_mindwell, scanend)) {
792 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
794 "[ticks %u, dwell min %lu scanend %lu]\n",
796 ticks, ss->ss_mindwell, scanend);
797 ss->ss_next = 0; /* reset to begining */
798 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
799 vap->iv_stats.is_scan_active++;
801 vap->iv_stats.is_scan_passive++;
803 ss->ss_ops->scan_restart(ss, vap); /* XXX? */
804 ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
805 IEEE80211_UNLOCK(ic);
809 /* past here, scandone is ``true'' if not in bg mode */
810 if ((ss->ss_flags & IEEE80211_SCAN_BGSCAN) == 0)
813 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
814 "%s: %s, [ticks %u, dwell min %lu scanend %lu]\n",
815 __func__, scandone ? "done" : "stopped",
816 ticks, ss->ss_mindwell, scanend);
819 * Since a cancellation may have occured during one of the
820 * driver calls (whilst unlocked), update scandone.
823 ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) != 0)) {
825 if_printf(vap->iv_ifp,
826 "%s: OOPS! scan cancelled during driver call (2)!\n",
832 * Clear the SCAN bit first in case frames are
833 * pending on the station power save queue. If
834 * we defer this then the dispatch of the frames
835 * may generate a request to cancel scanning.
838 ic->ic_flags &= ~IEEE80211_F_SCAN;
840 * Drop out of power save mode when a scan has
841 * completed. If this scan was prematurely terminated
842 * because it is a background scan then don't notify
843 * the ap; we'll either return to scanning after we
844 * receive the beacon frame or we'll drop out of power
845 * save mode because the beacon indicates we have frames
849 vap->iv_sta_ps(vap, 0);
850 if (ss->ss_next >= ss->ss_last) {
851 ieee80211_notify_scan_done(vap);
852 ic->ic_flags_ext &= ~IEEE80211_FEXT_BGSCAN;
855 SCAN_PRIVATE(ss)->ss_iflags &= ~(ISCAN_CANCEL|ISCAN_ABORT);
856 ss->ss_flags &= ~(IEEE80211_SCAN_ONCE | IEEE80211_SCAN_PICK1ST);
857 IEEE80211_UNLOCK(ic);
862 * Process a beacon or probe response frame.
865 ieee80211_swscan_add_scan(struct ieee80211vap *vap,
866 struct ieee80211_channel *curchan,
867 const struct ieee80211_scanparams *sp,
868 const struct ieee80211_frame *wh,
869 int subtype, int rssi, int noise)
871 struct ieee80211com *ic = vap->iv_ic;
872 struct ieee80211_scan_state *ss = ic->ic_scan;
876 * Frames received during startup are discarded to avoid
877 * using scan state setup on the initial entry to the timer
878 * callback. This can occur because the device may enable
879 * rx prior to our doing the initial channel change in the
882 if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_DISCARD)
884 #ifdef IEEE80211_DEBUG
885 if (ieee80211_msg_scan(vap) && (ic->ic_flags & IEEE80211_F_SCAN))
886 ieee80211_scan_dump_probe_beacon(subtype, 1, wh->i_addr2, sp, rssi);
888 if (ss->ss_ops != NULL &&
889 ss->ss_ops->scan_add(ss, curchan, sp, wh, subtype, rssi, noise)) {
891 * If we've reached the min dwell time terminate
892 * the timer so we'll switch to the next channel.
894 if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_MINDWELL) == 0 &&
895 time_after_eq(ticks, SCAN_PRIVATE(ss)->ss_chanmindwell)) {
896 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
897 "%s: chan %3d%c min dwell met (%u > %lu)\n",
899 ieee80211_chan2ieee(ic, ic->ic_curchan),
900 ieee80211_channel_type_char(ic->ic_curchan),
901 ticks, SCAN_PRIVATE(ss)->ss_chanmindwell);
902 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_MINDWELL;
904 * NB: trigger at next clock tick or wait for the
907 ic->ic_scan_mindwell(ss);
912 static struct ieee80211_scan_methods swscan_methods = {
913 .sc_attach = ieee80211_swscan_attach,
914 .sc_detach = ieee80211_swscan_detach,
915 .sc_vattach = ieee80211_swscan_vattach,
916 .sc_vdetach = ieee80211_swscan_vdetach,
917 .sc_set_scan_duration = ieee80211_swscan_set_scan_duration,
918 .sc_start_scan = ieee80211_swscan_start_scan,
919 .sc_check_scan = ieee80211_swscan_check_scan,
920 .sc_bg_scan = ieee80211_swscan_bg_scan,
921 .sc_cancel_scan = ieee80211_swscan_cancel_scan,
922 .sc_cancel_anyscan = ieee80211_swscan_cancel_anyscan,
923 .sc_scan_next = ieee80211_swscan_scan_next,
924 .sc_scan_done = ieee80211_swscan_scan_done,
925 .sc_scan_probe_curchan = ieee80211_swscan_probe_curchan,
926 .sc_add_scan = ieee80211_swscan_add_scan
930 * Default scan attach method.
933 ieee80211_swscan_attach(struct ieee80211com *ic)
935 struct scan_state *ss;
938 * Setup the default methods
940 ic->ic_scan_methods = &swscan_methods;
942 /* Allocate initial scan state */
943 ss = (struct scan_state *) IEEE80211_MALLOC(sizeof(struct scan_state),
944 M_80211_SCAN, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
949 callout_init_mtx(&ss->ss_scan_timer, IEEE80211_LOCK_OBJ(ic), 0);
950 cv_init(&ss->ss_scan_cv, "scan");
951 TASK_INIT(&ss->ss_scan_task, 0, scan_task, ss);
953 ic->ic_scan = &ss->base;
956 ic->ic_scan_curchan = scan_curchan;
957 ic->ic_scan_mindwell = scan_mindwell;