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/malloc.h>
39 #include <sys/condvar.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>
50 #include <net80211/ieee80211_scan_sw.h>
55 struct ieee80211_scan_state base; /* public state */
57 u_int ss_iflags; /* flags used internally */
58 #define ISCAN_MINDWELL 0x0001 /* min dwell time reached */
59 #define ISCAN_DISCARD 0x0002 /* discard rx'd frames */
60 #define ISCAN_INTERRUPT 0x0004 /* interrupt current scan */
61 #define ISCAN_CANCEL 0x0008 /* cancel current scan */
62 #define ISCAN_PAUSE (ISCAN_INTERRUPT | ISCAN_CANCEL)
63 #define ISCAN_ABORT 0x0010 /* end the scan immediately */
64 #define ISCAN_RUNNING 0x0020 /* scan was started */
66 unsigned long ss_chanmindwell; /* min dwell on curchan */
67 unsigned long ss_scanend; /* time scan must stop */
68 u_int ss_duration; /* duration for next scan */
69 struct task ss_scan_start; /* scan start */
70 struct timeout_task ss_scan_curchan; /* scan execution */
72 #define SCAN_PRIVATE(ss) ((struct scan_state *) ss)
75 * Amount of time to go off-channel during a background
76 * scan. This value should be large enough to catch most
77 * ap's but short enough that we can return on-channel
78 * before our listen interval expires.
81 * XXX check against configured listen interval
83 #define IEEE80211_SCAN_OFFCHANNEL msecs_to_ticks(150)
85 static void scan_curchan(struct ieee80211_scan_state *, unsigned long);
86 static void scan_mindwell(struct ieee80211_scan_state *);
87 static void scan_signal(struct ieee80211_scan_state *, int);
88 static void scan_signal_locked(struct ieee80211_scan_state *, int);
89 static void scan_start(void *, int);
90 static void scan_curchan_task(void *, int);
91 static void scan_end(struct ieee80211_scan_state *, int);
92 static void scan_done(struct ieee80211_scan_state *, int);
94 MALLOC_DEFINE(M_80211_SCAN, "80211scan", "802.11 scan state");
97 ieee80211_swscan_detach(struct ieee80211com *ic)
99 struct ieee80211_scan_state *ss = ic->ic_scan;
102 scan_signal(ss, ISCAN_ABORT);
103 ieee80211_draintask(ic, &SCAN_PRIVATE(ss)->ss_scan_start);
104 taskqueue_drain_timeout(ic->ic_tq,
105 &SCAN_PRIVATE(ss)->ss_scan_curchan);
106 KASSERT((ic->ic_flags & IEEE80211_F_SCAN) == 0,
107 ("scan still running"));
110 * For now, do the ss_ops detach here rather
111 * than ieee80211_scan_detach().
113 * I'll figure out how to cleanly split things up
116 if (ss->ss_ops != NULL) {
117 ss->ss_ops->scan_detach(ss);
121 IEEE80211_FREE(SCAN_PRIVATE(ss), M_80211_SCAN);
126 ieee80211_swscan_vattach(struct ieee80211vap *vap)
128 /* nothing to do for now */
130 * TODO: all of the vap scan calls should be methods!
136 ieee80211_swscan_vdetach(struct ieee80211vap *vap)
138 struct ieee80211com *ic = vap->iv_ic;
139 struct ieee80211_scan_state *ss = ic->ic_scan;
141 IEEE80211_LOCK_ASSERT(ic);
143 if (ss != NULL && ss->ss_vap == vap &&
144 (ic->ic_flags & IEEE80211_F_SCAN))
145 scan_signal_locked(ss, ISCAN_ABORT);
149 ieee80211_swscan_set_scan_duration(struct ieee80211vap *vap, u_int duration)
151 struct ieee80211com *ic = vap->iv_ic;
152 struct ieee80211_scan_state *ss = ic->ic_scan;
154 IEEE80211_LOCK_ASSERT(ic);
156 /* NB: flush frames rx'd before 1st channel change */
157 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
158 SCAN_PRIVATE(ss)->ss_duration = duration;
162 * Start a scan unless one is already going.
165 ieee80211_swscan_start_scan_locked(const struct ieee80211_scanner *scan,
166 struct ieee80211vap *vap, int flags, u_int duration,
167 u_int mindwell, u_int maxdwell,
168 u_int nssid, const struct ieee80211_scan_ssid ssids[])
170 struct ieee80211com *ic = vap->iv_ic;
171 struct ieee80211_scan_state *ss = ic->ic_scan;
173 IEEE80211_LOCK_ASSERT(ic);
175 if (ic->ic_flags & IEEE80211_F_CSAPENDING) {
176 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
177 "%s: scan inhibited by pending channel change\n", __func__);
178 } else if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
179 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
180 "%s: %s scan, duration %u mindwell %u maxdwell %u, desired mode %s, %s%s%s%s%s%s\n"
182 , flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"
183 , duration, mindwell, maxdwell
184 , ieee80211_phymode_name[vap->iv_des_mode]
185 , flags & IEEE80211_SCAN_FLUSH ? "flush" : "append"
186 , flags & IEEE80211_SCAN_NOPICK ? ", nopick" : ""
187 , flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : ""
188 , flags & IEEE80211_SCAN_NOBCAST ? ", nobcast" : ""
189 , flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : ""
190 , flags & IEEE80211_SCAN_ONCE ? ", once" : ""
193 ieee80211_scan_update_locked(vap, scan);
194 if (ss->ss_ops != NULL) {
195 if ((flags & IEEE80211_SCAN_NOSSID) == 0)
196 ieee80211_scan_copy_ssid(vap, ss, nssid, ssids);
198 /* NB: top 4 bits for internal use */
199 ss->ss_flags = flags & 0xfff;
200 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
201 vap->iv_stats.is_scan_active++;
203 vap->iv_stats.is_scan_passive++;
204 if (flags & IEEE80211_SCAN_FLUSH)
205 ss->ss_ops->scan_flush(ss);
206 if (flags & IEEE80211_SCAN_BGSCAN)
207 ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN;
209 /* Set duration for this particular scan */
210 ieee80211_swscan_set_scan_duration(vap, duration);
213 ss->ss_mindwell = mindwell;
214 ss->ss_maxdwell = maxdwell;
215 /* NB: scan_start must be before the scan runtask */
216 ss->ss_ops->scan_start(ss, vap);
217 #ifdef IEEE80211_DEBUG
218 if (ieee80211_msg_scan(vap))
219 ieee80211_scan_dump(ss);
220 #endif /* IEEE80211_DEBUG */
221 ic->ic_flags |= IEEE80211_F_SCAN;
223 /* Start scan task */
224 ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_start);
228 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
229 "%s: %s scan already in progress\n", __func__,
230 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
237 * Start a scan unless one is already going.
239 * Called without the comlock held; grab the comlock as appropriate.
242 ieee80211_swscan_start_scan(const struct ieee80211_scanner *scan,
243 struct ieee80211vap *vap, int flags,
244 u_int duration, u_int mindwell, u_int maxdwell,
245 u_int nssid, const struct ieee80211_scan_ssid ssids[])
247 struct ieee80211com *ic = vap->iv_ic;
250 IEEE80211_UNLOCK_ASSERT(ic);
253 result = ieee80211_swscan_start_scan_locked(scan, vap, flags, duration,
254 mindwell, maxdwell, nssid, ssids);
255 IEEE80211_UNLOCK(ic);
261 * Check the scan cache for an ap/channel to use; if that
262 * fails then kick off a new scan.
264 * Called with the comlock held.
266 * XXX TODO: split out!
269 ieee80211_swscan_check_scan(const struct ieee80211_scanner *scan,
270 struct ieee80211vap *vap, int flags,
271 u_int duration, u_int mindwell, u_int maxdwell,
272 u_int nssid, const struct ieee80211_scan_ssid ssids[])
274 struct ieee80211com *ic = vap->iv_ic;
275 struct ieee80211_scan_state *ss = ic->ic_scan;
278 IEEE80211_LOCK_ASSERT(ic);
280 if (ss->ss_ops != NULL) {
281 /* XXX verify ss_ops matches vap->iv_opmode */
282 if ((flags & IEEE80211_SCAN_NOSSID) == 0) {
284 * Update the ssid list and mark flags so if
285 * we call start_scan it doesn't duplicate work.
287 ieee80211_scan_copy_ssid(vap, ss, nssid, ssids);
288 flags |= IEEE80211_SCAN_NOSSID;
290 if ((ic->ic_flags & IEEE80211_F_SCAN) == 0 &&
291 (flags & IEEE80211_SCAN_FLUSH) == 0 &&
292 ieee80211_time_before(ticks, ic->ic_lastscan + vap->iv_scanvalid)) {
294 * We're not currently scanning and the cache is
295 * deemed hot enough to consult. Lock out others
296 * by marking IEEE80211_F_SCAN while we decide if
297 * something is already in the scan cache we can
298 * use. Also discard any frames that might come
299 * in while temporarily marked as scanning.
301 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
302 ic->ic_flags |= IEEE80211_F_SCAN;
304 /* NB: need to use supplied flags in check */
305 ss->ss_flags = flags & 0xff;
306 result = ss->ss_ops->scan_end(ss, vap);
308 ic->ic_flags &= ~IEEE80211_F_SCAN;
309 SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_DISCARD;
311 ieee80211_notify_scan_done(vap);
316 result = ieee80211_swscan_start_scan_locked(scan, vap, flags, duration,
317 mindwell, maxdwell, nssid, ssids);
323 * Restart a previous scan. If the previous scan completed
324 * then we start again using the existing channel list.
327 ieee80211_swscan_bg_scan(const struct ieee80211_scanner *scan,
328 struct ieee80211vap *vap, int flags)
330 struct ieee80211com *ic = vap->iv_ic;
331 struct ieee80211_scan_state *ss = ic->ic_scan;
333 /* XXX assert unlocked? */
334 // IEEE80211_UNLOCK_ASSERT(ic);
337 if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
340 * Go off-channel for a fixed interval that is large
341 * enough to catch most ap's but short enough that
342 * we can return on-channel before our listen interval
345 duration = IEEE80211_SCAN_OFFCHANNEL;
347 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
348 "%s: %s scan, ticks %u duration %u\n", __func__,
349 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive",
352 ieee80211_scan_update_locked(vap, scan);
353 if (ss->ss_ops != NULL) {
356 * A background scan does not select a new sta; it
357 * just refreshes the scan cache. Also, indicate
358 * the scan logic should follow the beacon schedule:
359 * we go off-channel and scan for a while, then
360 * return to the bss channel to receive a beacon,
361 * then go off-channel again. All during this time
362 * we notify the ap we're in power save mode. When
363 * the scan is complete we leave power save mode.
364 * If any beacon indicates there are frames pending
365 * for us then we drop out of power save mode
366 * (and background scan) automatically by way of the
367 * usual sta power save logic.
369 ss->ss_flags |= IEEE80211_SCAN_NOPICK
370 | IEEE80211_SCAN_BGSCAN
373 /* if previous scan completed, restart */
374 if (ss->ss_next >= ss->ss_last) {
375 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
376 vap->iv_stats.is_scan_active++;
378 vap->iv_stats.is_scan_passive++;
380 * NB: beware of the scan cache being flushed;
381 * if the channel list is empty use the
382 * scan_start method to populate it.
385 if (ss->ss_last != 0)
386 ss->ss_ops->scan_restart(ss, vap);
388 ss->ss_ops->scan_start(ss, vap);
389 #ifdef IEEE80211_DEBUG
390 if (ieee80211_msg_scan(vap))
391 ieee80211_scan_dump(ss);
392 #endif /* IEEE80211_DEBUG */
395 ieee80211_swscan_set_scan_duration(vap, duration);
396 ss->ss_maxdwell = duration;
397 ic->ic_flags |= IEEE80211_F_SCAN;
398 ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN;
399 ieee80211_runtask(ic,
400 &SCAN_PRIVATE(ss)->ss_scan_start);
405 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
406 "%s: %s scan already in progress\n", __func__,
407 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
409 IEEE80211_UNLOCK(ic);
411 /* NB: racey, does it matter? */
412 return (ic->ic_flags & IEEE80211_F_SCAN);
416 * Taskqueue work to cancel a scan.
418 * Note: for offload scan devices, we may want to call into the
419 * driver to try and cancel scanning, however it may not be cancelable.
422 cancel_scan(struct ieee80211vap *vap, int any, const char *func)
424 struct ieee80211com *ic = vap->iv_ic;
425 struct ieee80211_scan_state *ss = ic->ic_scan;
426 struct scan_state *ss_priv = SCAN_PRIVATE(ss);
430 signal = any ? ISCAN_PAUSE : ISCAN_CANCEL;
431 if ((ic->ic_flags & IEEE80211_F_SCAN) &&
432 (any || ss->ss_vap == vap) &&
433 (ss_priv->ss_iflags & signal) == 0) {
434 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
435 "%s: %s %s scan\n", func,
436 any ? "pause" : "cancel",
437 ss->ss_flags & IEEE80211_SCAN_ACTIVE ?
438 "active" : "passive");
440 /* clear bg scan NOPICK */
441 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
442 /* mark request and wake up the scan task */
443 scan_signal_locked(ss, signal);
445 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
446 "%s: called; F_SCAN=%d, vap=%s, signal=%d\n",
448 !! (ic->ic_flags & IEEE80211_F_SCAN),
449 (ss->ss_vap == vap ? "match" : "nomatch"),
450 !! (ss_priv->ss_iflags & signal));
452 IEEE80211_UNLOCK(ic);
456 * Cancel any scan currently going on for the specified vap.
459 ieee80211_swscan_cancel_scan(struct ieee80211vap *vap)
461 cancel_scan(vap, 0, __func__);
465 * Cancel any scan currently going on.
468 ieee80211_swscan_cancel_anyscan(struct ieee80211vap *vap)
471 /* XXX for now - just don't do this per packet. */
472 if (vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD)
475 cancel_scan(vap, 1, __func__);
479 * Manually switch to the next channel in the channel list.
480 * Provided for drivers that manage scanning themselves
481 * (e.g. for firmware-based devices).
484 ieee80211_swscan_scan_next(struct ieee80211vap *vap)
486 struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
488 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: called\n", __func__);
490 /* wake up the scan task */
495 * Manually stop a scan that is currently running.
496 * Provided for drivers that are not able to scan single channels
497 * (e.g. for firmware-based devices).
500 ieee80211_swscan_scan_done(struct ieee80211vap *vap)
502 struct ieee80211com *ic = vap->iv_ic;
503 struct ieee80211_scan_state *ss = ic->ic_scan;
505 IEEE80211_LOCK_ASSERT(ic);
507 scan_signal_locked(ss, 0);
511 * Probe the current channel, if allowed, while scanning.
512 * If the channel is not marked passive-only then send
513 * a probe request immediately. Otherwise mark state and
514 * listen for beacons on the channel; if we receive something
515 * then we'll transmit a probe request.
518 ieee80211_swscan_probe_curchan(struct ieee80211vap *vap, int force)
520 struct ieee80211com *ic = vap->iv_ic;
521 struct ieee80211_scan_state *ss = ic->ic_scan;
522 struct ifnet *ifp = vap->iv_ifp;
526 * Full-offload scan devices don't require this.
528 if (vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD)
532 * Send directed probe requests followed by any
533 * broadcast probe request.
534 * XXX remove dependence on ic/vap->iv_bss
536 for (i = 0; i < ss->ss_nssid; i++)
537 ieee80211_send_probereq(vap->iv_bss,
538 vap->iv_myaddr, ifp->if_broadcastaddr,
539 ifp->if_broadcastaddr,
540 ss->ss_ssid[i].ssid, ss->ss_ssid[i].len);
541 if ((ss->ss_flags & IEEE80211_SCAN_NOBCAST) == 0)
542 ieee80211_send_probereq(vap->iv_bss,
543 vap->iv_myaddr, ifp->if_broadcastaddr,
544 ifp->if_broadcastaddr,
549 * Scan curchan. If this is an active scan and the channel
550 * is not marked passive then send probe request frame(s).
551 * Arrange for the channel change after maxdwell ticks.
554 scan_curchan(struct ieee80211_scan_state *ss, unsigned long maxdwell)
556 struct ieee80211vap *vap = ss->ss_vap;
557 struct ieee80211com *ic = ss->ss_ic;
559 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
560 "%s: calling; maxdwell=%lu\n",
564 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
565 ieee80211_probe_curchan(vap, 0);
566 taskqueue_enqueue_timeout(ic->ic_tq,
567 &SCAN_PRIVATE(ss)->ss_scan_curchan, maxdwell);
568 IEEE80211_UNLOCK(ic);
572 scan_signal(struct ieee80211_scan_state *ss, int iflags)
574 struct ieee80211com *ic = ss->ss_ic;
576 IEEE80211_UNLOCK_ASSERT(ic);
579 scan_signal_locked(ss, iflags);
580 IEEE80211_UNLOCK(ic);
584 scan_signal_locked(struct ieee80211_scan_state *ss, int iflags)
586 struct scan_state *ss_priv = SCAN_PRIVATE(ss);
587 struct timeout_task *scan_task = &ss_priv->ss_scan_curchan;
588 struct ieee80211com *ic = ss->ss_ic;
590 IEEE80211_LOCK_ASSERT(ic);
592 ss_priv->ss_iflags |= iflags;
593 if (ss_priv->ss_iflags & ISCAN_RUNNING) {
594 if (taskqueue_cancel_timeout(ic->ic_tq, scan_task, NULL) == 0)
595 taskqueue_enqueue_timeout(ic->ic_tq, scan_task, 0);
600 * Handle mindwell requirements completed; initiate a channel
601 * change to the next channel asap.
604 scan_mindwell(struct ieee80211_scan_state *ss)
607 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, "%s: called\n",
614 scan_start(void *arg, int pending)
616 #define ISCAN_REP (ISCAN_MINDWELL | ISCAN_DISCARD)
617 struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg;
618 struct scan_state *ss_priv = SCAN_PRIVATE(ss);
619 struct ieee80211vap *vap = ss->ss_vap;
620 struct ieee80211com *ic = ss->ss_ic;
623 if (vap == NULL || (ic->ic_flags & IEEE80211_F_SCAN) == 0 ||
624 (ss_priv->ss_iflags & ISCAN_ABORT)) {
625 /* Cancelled before we started */
630 if (ss->ss_next == ss->ss_last) {
631 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
632 "%s: no channels to scan\n", __func__);
638 * Put the station into power save mode.
640 * This is only required if we're not a full-offload devices;
641 * those devices manage scan/traffic differently.
643 if (((vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) == 0) &&
644 vap->iv_opmode == IEEE80211_M_STA &&
645 vap->iv_state == IEEE80211_S_RUN) {
646 if ((vap->iv_bss->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) {
647 /* Enable station power save mode */
648 vap->iv_sta_ps(vap, 1);
649 /* Wait until null data frame will be ACK'ed */
650 mtx_sleep(vap, IEEE80211_LOCK_OBJ(ic), PCATCH,
651 "sta_ps", msecs_to_ticks(10));
652 if (ss_priv->ss_iflags & ISCAN_ABORT) {
659 ss_priv->ss_scanend = ticks + ss_priv->ss_duration;
661 /* XXX scan state can change! Re-validate scan state! */
663 IEEE80211_UNLOCK(ic);
665 ic->ic_scan_start(ic); /* notify driver */
667 scan_curchan_task(ss, 0);
671 scan_curchan_task(void *arg, int pending)
673 struct ieee80211_scan_state *ss = arg;
674 struct scan_state *ss_priv = SCAN_PRIVATE(ss);
675 struct ieee80211com *ic = ss->ss_ic;
676 struct ieee80211_channel *chan;
677 unsigned long maxdwell;
682 scandone = (ss->ss_next >= ss->ss_last) ||
683 (ss_priv->ss_iflags & ISCAN_CANCEL) != 0;
685 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN,
686 "%s: loop start; scandone=%d\n",
690 if (scandone || (ss->ss_flags & IEEE80211_SCAN_GOTPICK) ||
691 (ss_priv->ss_iflags & ISCAN_ABORT) ||
692 ieee80211_time_after(ticks + ss->ss_mindwell, ss_priv->ss_scanend)) {
693 ss_priv->ss_iflags &= ~ISCAN_RUNNING;
694 scan_end(ss, scandone);
697 ss_priv->ss_iflags |= ISCAN_RUNNING;
699 chan = ss->ss_chans[ss->ss_next++];
702 * Watch for truncation due to the scan end time.
704 if (ieee80211_time_after(ticks + ss->ss_maxdwell, ss_priv->ss_scanend))
705 maxdwell = ss_priv->ss_scanend - ticks;
707 maxdwell = ss->ss_maxdwell;
709 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN,
710 "%s: chan %3d%c -> %3d%c [%s, dwell min %lums max %lums]\n",
712 ieee80211_chan2ieee(ic, ic->ic_curchan),
713 ieee80211_channel_type_char(ic->ic_curchan),
714 ieee80211_chan2ieee(ic, chan),
715 ieee80211_channel_type_char(chan),
716 (ss->ss_flags & IEEE80211_SCAN_ACTIVE) &&
717 (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0 ?
718 "active" : "passive",
719 ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(maxdwell));
722 * Potentially change channel and phy mode.
724 ic->ic_curchan = chan;
725 ic->ic_rt = ieee80211_get_ratetable(chan);
726 IEEE80211_UNLOCK(ic);
728 * Perform the channel change and scan unlocked so the driver
729 * may sleep. Once set_channel returns the hardware has
730 * completed the channel change.
732 ic->ic_set_channel(ic);
733 ieee80211_radiotap_chan_change(ic);
736 * Scan curchan. Drivers for "intelligent hardware"
737 * override ic_scan_curchan to tell the device to do
738 * the work. Otherwise we manage the work ourselves;
739 * sending a probe request (as needed), and arming the
740 * timeout to switch channels after maxdwell ticks.
742 * scan_curchan should only pause for the time required to
743 * prepare/initiate the hardware for the scan (if at all).
745 ic->ic_scan_curchan(ss, maxdwell);
748 /* XXX scan state can change! Re-validate scan state! */
750 ss_priv->ss_chanmindwell = ticks + ss->ss_mindwell;
751 /* clear mindwell lock and initial channel change flush */
752 ss_priv->ss_iflags &= ~ISCAN_REP;
754 if (ss_priv->ss_iflags & (ISCAN_CANCEL|ISCAN_ABORT)) {
755 taskqueue_cancel_timeout(ic->ic_tq, &ss_priv->ss_scan_curchan,
760 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, "%s: waiting\n",
762 IEEE80211_UNLOCK(ic);
766 scan_end(struct ieee80211_scan_state *ss, int scandone)
768 struct scan_state *ss_priv = SCAN_PRIVATE(ss);
769 struct ieee80211vap *vap = ss->ss_vap;
770 struct ieee80211com *ic = ss->ss_ic;
772 IEEE80211_LOCK_ASSERT(ic);
774 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: out\n", __func__);
776 if (ss_priv->ss_iflags & ISCAN_ABORT) {
777 scan_done(ss, scandone);
781 IEEE80211_UNLOCK(ic);
782 ic->ic_scan_end(ic); /* notify driver */
784 /* XXX scan state can change! Re-validate scan state! */
787 * Since a cancellation may have occurred during one of the
788 * driver calls (whilst unlocked), update scandone.
790 if (scandone == 0 && (ss_priv->ss_iflags & ISCAN_CANCEL) != 0) {
792 if_printf(vap->iv_ifp,
793 "%s: OOPS! scan cancelled during driver call (1)!\n",
799 * Record scan complete time. Note that we also do
800 * this when canceled so any background scan will
801 * not be restarted for a while.
804 ic->ic_lastscan = ticks;
805 /* return to the bss channel */
806 if (ic->ic_bsschan != IEEE80211_CHAN_ANYC &&
807 ic->ic_curchan != ic->ic_bsschan) {
808 ieee80211_setupcurchan(ic, ic->ic_bsschan);
809 IEEE80211_UNLOCK(ic);
810 ic->ic_set_channel(ic);
811 ieee80211_radiotap_chan_change(ic);
814 /* clear internal flags and any indication of a pick */
815 ss_priv->ss_iflags &= ~ISCAN_REP;
816 ss->ss_flags &= ~IEEE80211_SCAN_GOTPICK;
819 * If not canceled and scan completed, do post-processing.
820 * If the callback function returns 0, then it wants to
821 * continue/restart scanning. Unfortunately we needed to
822 * notify the driver to end the scan above to avoid having
823 * rx frames alter the scan candidate list.
825 if ((ss_priv->ss_iflags & ISCAN_CANCEL) == 0 &&
826 !ss->ss_ops->scan_end(ss, vap) &&
827 (ss->ss_flags & IEEE80211_SCAN_ONCE) == 0 &&
828 ieee80211_time_before(ticks + ss->ss_mindwell, ss_priv->ss_scanend)) {
829 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
831 "[ticks %u, dwell min %lu scanend %lu]\n",
833 ticks, ss->ss_mindwell, ss_priv->ss_scanend);
834 ss->ss_next = 0; /* reset to beginning */
835 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
836 vap->iv_stats.is_scan_active++;
838 vap->iv_stats.is_scan_passive++;
840 ss->ss_ops->scan_restart(ss, vap); /* XXX? */
841 ieee80211_runtask(ic, &ss_priv->ss_scan_start);
842 IEEE80211_UNLOCK(ic);
846 /* past here, scandone is ``true'' if not in bg mode */
847 if ((ss->ss_flags & IEEE80211_SCAN_BGSCAN) == 0)
850 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
851 "%s: %s, [ticks %u, dwell min %lu scanend %lu]\n",
852 __func__, scandone ? "done" : "stopped",
853 ticks, ss->ss_mindwell, ss_priv->ss_scanend);
856 * Since a cancellation may have occurred during one of the
857 * driver calls (whilst unlocked), update scandone.
859 if (scandone == 0 && (ss_priv->ss_iflags & ISCAN_CANCEL) != 0) {
861 if_printf(vap->iv_ifp,
862 "%s: OOPS! scan cancelled during driver call (2)!\n",
867 scan_done(ss, scandone);
871 scan_done(struct ieee80211_scan_state *ss, int scandone)
873 struct scan_state *ss_priv = SCAN_PRIVATE(ss);
874 struct ieee80211com *ic = ss->ss_ic;
875 struct ieee80211vap *vap = ss->ss_vap;
877 IEEE80211_LOCK_ASSERT(ic);
880 * Clear the SCAN bit first in case frames are
881 * pending on the station power save queue. If
882 * we defer this then the dispatch of the frames
883 * may generate a request to cancel scanning.
885 ic->ic_flags &= ~IEEE80211_F_SCAN;
888 * Drop out of power save mode when a scan has
889 * completed. If this scan was prematurely terminated
890 * because it is a background scan then don't notify
891 * the ap; we'll either return to scanning after we
892 * receive the beacon frame or we'll drop out of power
893 * save mode because the beacon indicates we have frames
898 * If we're not a scan offload device, come back out of
899 * station powersave. Offload devices handle this themselves.
901 if ((vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) == 0)
902 vap->iv_sta_ps(vap, 0);
903 if (ss->ss_next >= ss->ss_last)
904 ic->ic_flags_ext &= ~IEEE80211_FEXT_BGSCAN;
906 /* send 'scan done' event if not interrupted due to traffic. */
907 if (!(ss_priv->ss_iflags & ISCAN_INTERRUPT))
908 ieee80211_notify_scan_done(vap);
910 ss_priv->ss_iflags &= ~(ISCAN_PAUSE | ISCAN_ABORT);
911 ss_priv->ss_scanend = 0;
912 ss->ss_flags &= ~(IEEE80211_SCAN_ONCE | IEEE80211_SCAN_PICK1ST);
913 IEEE80211_UNLOCK(ic);
918 * Process a beacon or probe response frame.
921 ieee80211_swscan_add_scan(struct ieee80211vap *vap,
922 struct ieee80211_channel *curchan,
923 const struct ieee80211_scanparams *sp,
924 const struct ieee80211_frame *wh,
925 int subtype, int rssi, int noise)
927 struct ieee80211com *ic = vap->iv_ic;
928 struct ieee80211_scan_state *ss = ic->ic_scan;
932 * Frames received during startup are discarded to avoid
933 * using scan state setup on the initial entry to the timer
934 * callback. This can occur because the device may enable
935 * rx prior to our doing the initial channel change in the
938 if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_DISCARD)
940 #ifdef IEEE80211_DEBUG
941 if (ieee80211_msg_scan(vap) && (ic->ic_flags & IEEE80211_F_SCAN))
942 ieee80211_scan_dump_probe_beacon(subtype, 1, wh->i_addr2, sp, rssi);
944 if (ss->ss_ops != NULL &&
945 ss->ss_ops->scan_add(ss, curchan, sp, wh, subtype, rssi, noise)) {
947 * If we've reached the min dwell time terminate
948 * the timer so we'll switch to the next channel.
950 if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_MINDWELL) == 0 &&
951 ieee80211_time_after_eq(ticks, SCAN_PRIVATE(ss)->ss_chanmindwell)) {
952 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
953 "%s: chan %3d%c min dwell met (%u > %lu)\n",
955 ieee80211_chan2ieee(ic, ic->ic_curchan),
956 ieee80211_channel_type_char(ic->ic_curchan),
957 ticks, SCAN_PRIVATE(ss)->ss_chanmindwell);
958 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_MINDWELL;
960 * NB: trigger at next clock tick or wait for the
963 ic->ic_scan_mindwell(ss);
968 static struct ieee80211_scan_methods swscan_methods = {
969 .sc_attach = ieee80211_swscan_attach,
970 .sc_detach = ieee80211_swscan_detach,
971 .sc_vattach = ieee80211_swscan_vattach,
972 .sc_vdetach = ieee80211_swscan_vdetach,
973 .sc_set_scan_duration = ieee80211_swscan_set_scan_duration,
974 .sc_start_scan = ieee80211_swscan_start_scan,
975 .sc_check_scan = ieee80211_swscan_check_scan,
976 .sc_bg_scan = ieee80211_swscan_bg_scan,
977 .sc_cancel_scan = ieee80211_swscan_cancel_scan,
978 .sc_cancel_anyscan = ieee80211_swscan_cancel_anyscan,
979 .sc_scan_next = ieee80211_swscan_scan_next,
980 .sc_scan_done = ieee80211_swscan_scan_done,
981 .sc_scan_probe_curchan = ieee80211_swscan_probe_curchan,
982 .sc_add_scan = ieee80211_swscan_add_scan
986 * Default scan attach method.
989 ieee80211_swscan_attach(struct ieee80211com *ic)
991 struct scan_state *ss;
994 * Setup the default methods
996 ic->ic_scan_methods = &swscan_methods;
998 /* Allocate initial scan state */
999 ss = (struct scan_state *) IEEE80211_MALLOC(sizeof(struct scan_state),
1000 M_80211_SCAN, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
1005 TASK_INIT(&ss->ss_scan_start, 0, scan_start, ss);
1006 TIMEOUT_TASK_INIT(ic->ic_tq, &ss->ss_scan_curchan, 0,
1007 scan_curchan_task, ss);
1009 ic->ic_scan = &ss->base;
1010 ss->base.ss_ic = ic;
1012 ic->ic_scan_curchan = scan_curchan;
1013 ic->ic_scan_mindwell = scan_mindwell;