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 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
302 "cache hot; ic_lastscan=%d, scanvalid=%d, ticks=%d\n",
306 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
307 ic->ic_flags |= IEEE80211_F_SCAN;
309 /* NB: need to use supplied flags in check */
310 ss->ss_flags = flags & 0xff;
311 result = ss->ss_ops->scan_end(ss, vap);
313 ic->ic_flags &= ~IEEE80211_F_SCAN;
314 SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_DISCARD;
315 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
316 "%s: scan_end returned %d\n", __func__, result);
318 ieee80211_notify_scan_done(vap);
323 result = ieee80211_swscan_start_scan_locked(scan, vap, flags, duration,
324 mindwell, maxdwell, nssid, ssids);
330 * Restart a previous scan. If the previous scan completed
331 * then we start again using the existing channel list.
334 ieee80211_swscan_bg_scan(const struct ieee80211_scanner *scan,
335 struct ieee80211vap *vap, int flags)
337 struct ieee80211com *ic = vap->iv_ic;
338 struct ieee80211_scan_state *ss = ic->ic_scan;
340 /* XXX assert unlocked? */
341 // IEEE80211_UNLOCK_ASSERT(ic);
344 if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
347 * Go off-channel for a fixed interval that is large
348 * enough to catch most ap's but short enough that
349 * we can return on-channel before our listen interval
352 duration = IEEE80211_SCAN_OFFCHANNEL;
354 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
355 "%s: %s scan, ticks %u duration %u\n", __func__,
356 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive",
359 ieee80211_scan_update_locked(vap, scan);
360 if (ss->ss_ops != NULL) {
363 * A background scan does not select a new sta; it
364 * just refreshes the scan cache. Also, indicate
365 * the scan logic should follow the beacon schedule:
366 * we go off-channel and scan for a while, then
367 * return to the bss channel to receive a beacon,
368 * then go off-channel again. All during this time
369 * we notify the ap we're in power save mode. When
370 * the scan is complete we leave power save mode.
371 * If any beacon indicates there are frames pending
372 * for us then we drop out of power save mode
373 * (and background scan) automatically by way of the
374 * usual sta power save logic.
376 ss->ss_flags |= IEEE80211_SCAN_NOPICK
377 | IEEE80211_SCAN_BGSCAN
380 /* if previous scan completed, restart */
381 if (ss->ss_next >= ss->ss_last) {
382 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
383 vap->iv_stats.is_scan_active++;
385 vap->iv_stats.is_scan_passive++;
387 * NB: beware of the scan cache being flushed;
388 * if the channel list is empty use the
389 * scan_start method to populate it.
392 if (ss->ss_last != 0)
393 ss->ss_ops->scan_restart(ss, vap);
395 ss->ss_ops->scan_start(ss, vap);
396 #ifdef IEEE80211_DEBUG
397 if (ieee80211_msg_scan(vap))
398 ieee80211_scan_dump(ss);
399 #endif /* IEEE80211_DEBUG */
402 ieee80211_swscan_set_scan_duration(vap, duration);
403 ss->ss_maxdwell = duration;
404 ic->ic_flags |= IEEE80211_F_SCAN;
405 ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN;
406 ieee80211_runtask(ic,
407 &SCAN_PRIVATE(ss)->ss_scan_start);
412 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
413 "%s: %s scan already in progress\n", __func__,
414 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
416 IEEE80211_UNLOCK(ic);
418 /* NB: racey, does it matter? */
419 return (ic->ic_flags & IEEE80211_F_SCAN);
423 * Taskqueue work to cancel a scan.
425 * Note: for offload scan devices, we may want to call into the
426 * driver to try and cancel scanning, however it may not be cancelable.
429 cancel_scan(struct ieee80211vap *vap, int any, const char *func)
431 struct ieee80211com *ic = vap->iv_ic;
432 struct ieee80211_scan_state *ss = ic->ic_scan;
433 struct scan_state *ss_priv = SCAN_PRIVATE(ss);
437 signal = any ? ISCAN_PAUSE : ISCAN_CANCEL;
438 if ((ic->ic_flags & IEEE80211_F_SCAN) &&
439 (any || ss->ss_vap == vap) &&
440 (ss_priv->ss_iflags & signal) == 0) {
441 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
442 "%s: %s %s scan\n", func,
443 any ? "pause" : "cancel",
444 ss->ss_flags & IEEE80211_SCAN_ACTIVE ?
445 "active" : "passive");
447 /* clear bg scan NOPICK */
448 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
449 /* mark request and wake up the scan task */
450 scan_signal_locked(ss, signal);
452 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
453 "%s: called; F_SCAN=%d, vap=%s, signal=%d\n",
455 !! (ic->ic_flags & IEEE80211_F_SCAN),
456 (ss->ss_vap == vap ? "match" : "nomatch"),
457 !! (ss_priv->ss_iflags & signal));
459 IEEE80211_UNLOCK(ic);
463 * Cancel any scan currently going on for the specified vap.
466 ieee80211_swscan_cancel_scan(struct ieee80211vap *vap)
468 cancel_scan(vap, 0, __func__);
472 * Cancel any scan currently going on.
475 ieee80211_swscan_cancel_anyscan(struct ieee80211vap *vap)
478 /* XXX for now - just don't do this per packet. */
479 if (vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD)
482 cancel_scan(vap, 1, __func__);
486 * Manually switch to the next channel in the channel list.
487 * Provided for drivers that manage scanning themselves
488 * (e.g. for firmware-based devices).
491 ieee80211_swscan_scan_next(struct ieee80211vap *vap)
493 struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
495 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: called\n", __func__);
497 /* wake up the scan task */
502 * Manually stop a scan that is currently running.
503 * Provided for drivers that are not able to scan single channels
504 * (e.g. for firmware-based devices).
507 ieee80211_swscan_scan_done(struct ieee80211vap *vap)
509 struct ieee80211com *ic = vap->iv_ic;
510 struct ieee80211_scan_state *ss = ic->ic_scan;
512 IEEE80211_LOCK_ASSERT(ic);
514 scan_signal_locked(ss, 0);
518 * Probe the current channel, if allowed, while scanning.
519 * If the channel is not marked passive-only then send
520 * a probe request immediately. Otherwise mark state and
521 * listen for beacons on the channel; if we receive something
522 * then we'll transmit a probe request.
525 ieee80211_swscan_probe_curchan(struct ieee80211vap *vap, int force)
527 struct ieee80211com *ic = vap->iv_ic;
528 struct ieee80211_scan_state *ss = ic->ic_scan;
529 struct ifnet *ifp = vap->iv_ifp;
533 * Full-offload scan devices don't require this.
535 if (vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD)
539 * Send directed probe requests followed by any
540 * broadcast probe request.
541 * XXX remove dependence on ic/vap->iv_bss
543 for (i = 0; i < ss->ss_nssid; i++)
544 ieee80211_send_probereq(vap->iv_bss,
545 vap->iv_myaddr, ifp->if_broadcastaddr,
546 ifp->if_broadcastaddr,
547 ss->ss_ssid[i].ssid, ss->ss_ssid[i].len);
548 if ((ss->ss_flags & IEEE80211_SCAN_NOBCAST) == 0)
549 ieee80211_send_probereq(vap->iv_bss,
550 vap->iv_myaddr, ifp->if_broadcastaddr,
551 ifp->if_broadcastaddr,
556 * Scan curchan. If this is an active scan and the channel
557 * is not marked passive then send probe request frame(s).
558 * Arrange for the channel change after maxdwell ticks.
561 scan_curchan(struct ieee80211_scan_state *ss, unsigned long maxdwell)
563 struct ieee80211vap *vap = ss->ss_vap;
564 struct ieee80211com *ic = ss->ss_ic;
566 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
567 "%s: calling; maxdwell=%lu\n",
571 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
572 ieee80211_probe_curchan(vap, 0);
573 taskqueue_enqueue_timeout(ic->ic_tq,
574 &SCAN_PRIVATE(ss)->ss_scan_curchan, maxdwell);
575 IEEE80211_UNLOCK(ic);
579 scan_signal(struct ieee80211_scan_state *ss, int iflags)
581 struct ieee80211com *ic = ss->ss_ic;
583 IEEE80211_UNLOCK_ASSERT(ic);
586 scan_signal_locked(ss, iflags);
587 IEEE80211_UNLOCK(ic);
591 scan_signal_locked(struct ieee80211_scan_state *ss, int iflags)
593 struct scan_state *ss_priv = SCAN_PRIVATE(ss);
594 struct timeout_task *scan_task = &ss_priv->ss_scan_curchan;
595 struct ieee80211com *ic = ss->ss_ic;
597 IEEE80211_LOCK_ASSERT(ic);
599 ss_priv->ss_iflags |= iflags;
600 if (ss_priv->ss_iflags & ISCAN_RUNNING) {
601 if (taskqueue_cancel_timeout(ic->ic_tq, scan_task, NULL) == 0)
602 taskqueue_enqueue_timeout(ic->ic_tq, scan_task, 0);
607 * Handle mindwell requirements completed; initiate a channel
608 * change to the next channel asap.
611 scan_mindwell(struct ieee80211_scan_state *ss)
614 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, "%s: called\n",
621 scan_start(void *arg, int pending)
623 #define ISCAN_REP (ISCAN_MINDWELL | ISCAN_DISCARD)
624 struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg;
625 struct scan_state *ss_priv = SCAN_PRIVATE(ss);
626 struct ieee80211vap *vap = ss->ss_vap;
627 struct ieee80211com *ic = ss->ss_ic;
630 if (vap == NULL || (ic->ic_flags & IEEE80211_F_SCAN) == 0 ||
631 (ss_priv->ss_iflags & ISCAN_ABORT)) {
632 /* Cancelled before we started */
637 if (ss->ss_next == ss->ss_last) {
638 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
639 "%s: no channels to scan\n", __func__);
645 * Put the station into power save mode.
647 * This is only required if we're not a full-offload devices;
648 * those devices manage scan/traffic differently.
650 if (((vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) == 0) &&
651 vap->iv_opmode == IEEE80211_M_STA &&
652 vap->iv_state == IEEE80211_S_RUN) {
653 if ((vap->iv_bss->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) {
654 /* Enable station power save mode */
655 vap->iv_sta_ps(vap, 1);
656 /* Wait until null data frame will be ACK'ed */
657 mtx_sleep(vap, IEEE80211_LOCK_OBJ(ic), PCATCH,
658 "sta_ps", msecs_to_ticks(10));
659 if (ss_priv->ss_iflags & ISCAN_ABORT) {
666 ss_priv->ss_scanend = ticks + ss_priv->ss_duration;
668 /* XXX scan state can change! Re-validate scan state! */
670 IEEE80211_UNLOCK(ic);
672 ic->ic_scan_start(ic); /* notify driver */
674 scan_curchan_task(ss, 0);
678 scan_curchan_task(void *arg, int pending)
680 struct ieee80211_scan_state *ss = arg;
681 struct scan_state *ss_priv = SCAN_PRIVATE(ss);
682 struct ieee80211com *ic = ss->ss_ic;
683 struct ieee80211_channel *chan;
684 unsigned long maxdwell;
685 int scandone, scanstop;
690 * Note: only /end/ the scan if we're CANCEL rather than
691 * CANCEL+INTERRUPT (ie, 'PAUSE').
693 * We can stop the scan if we hit cancel, but we shouldn't
694 * call scan_end(ss, 1) if we're just PAUSEing the scan.
696 scandone = (ss->ss_next >= ss->ss_last) ||
697 ((ss_priv->ss_iflags & ISCAN_PAUSE) == ISCAN_CANCEL);
698 scanstop = (ss->ss_next >= ss->ss_last) ||
699 ((ss_priv->ss_iflags & ISCAN_CANCEL) != 0);
701 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN,
702 "%s: loop start; scandone=%d, scanstop=%d, ss_iflags=0x%x, ss_next=%u, ss_last=%u\n",
706 (uint32_t) ss_priv->ss_iflags,
707 (uint32_t) ss->ss_next,
708 (uint32_t) ss->ss_last);
710 if (scanstop || (ss->ss_flags & IEEE80211_SCAN_GOTPICK) ||
711 (ss_priv->ss_iflags & ISCAN_ABORT) ||
712 ieee80211_time_after(ticks + ss->ss_mindwell, ss_priv->ss_scanend)) {
713 ss_priv->ss_iflags &= ~ISCAN_RUNNING;
714 scan_end(ss, scandone);
717 ss_priv->ss_iflags |= ISCAN_RUNNING;
719 chan = ss->ss_chans[ss->ss_next++];
722 * Watch for truncation due to the scan end time.
724 if (ieee80211_time_after(ticks + ss->ss_maxdwell, ss_priv->ss_scanend))
725 maxdwell = ss_priv->ss_scanend - ticks;
727 maxdwell = ss->ss_maxdwell;
729 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN,
730 "%s: chan %3d%c -> %3d%c [%s, dwell min %lums max %lums]\n",
732 ieee80211_chan2ieee(ic, ic->ic_curchan),
733 ieee80211_channel_type_char(ic->ic_curchan),
734 ieee80211_chan2ieee(ic, chan),
735 ieee80211_channel_type_char(chan),
736 (ss->ss_flags & IEEE80211_SCAN_ACTIVE) &&
737 (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0 ?
738 "active" : "passive",
739 ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(maxdwell));
742 * Potentially change channel and phy mode.
744 ic->ic_curchan = chan;
745 ic->ic_rt = ieee80211_get_ratetable(chan);
746 IEEE80211_UNLOCK(ic);
748 * Perform the channel change and scan unlocked so the driver
749 * may sleep. Once set_channel returns the hardware has
750 * completed the channel change.
752 ic->ic_set_channel(ic);
753 ieee80211_radiotap_chan_change(ic);
756 * Scan curchan. Drivers for "intelligent hardware"
757 * override ic_scan_curchan to tell the device to do
758 * the work. Otherwise we manage the work ourselves;
759 * sending a probe request (as needed), and arming the
760 * timeout to switch channels after maxdwell ticks.
762 * scan_curchan should only pause for the time required to
763 * prepare/initiate the hardware for the scan (if at all).
765 ic->ic_scan_curchan(ss, maxdwell);
768 /* XXX scan state can change! Re-validate scan state! */
770 ss_priv->ss_chanmindwell = ticks + ss->ss_mindwell;
771 /* clear mindwell lock and initial channel change flush */
772 ss_priv->ss_iflags &= ~ISCAN_REP;
774 if (ss_priv->ss_iflags & (ISCAN_CANCEL|ISCAN_ABORT)) {
775 taskqueue_cancel_timeout(ic->ic_tq, &ss_priv->ss_scan_curchan,
780 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, "%s: waiting\n",
782 IEEE80211_UNLOCK(ic);
786 scan_end(struct ieee80211_scan_state *ss, int scandone)
788 struct scan_state *ss_priv = SCAN_PRIVATE(ss);
789 struct ieee80211vap *vap = ss->ss_vap;
790 struct ieee80211com *ic = ss->ss_ic;
792 IEEE80211_LOCK_ASSERT(ic);
794 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: out\n", __func__);
796 if (ss_priv->ss_iflags & ISCAN_ABORT) {
797 scan_done(ss, scandone);
801 IEEE80211_UNLOCK(ic);
802 ic->ic_scan_end(ic); /* notify driver */
804 /* XXX scan state can change! Re-validate scan state! */
807 * Since a cancellation may have occurred during one of the
808 * driver calls (whilst unlocked), update scandone.
810 if ((scandone == 0) && ((ss_priv->ss_iflags & ISCAN_PAUSE) == ISCAN_CANCEL)) {
812 if_printf(vap->iv_ifp,
813 "%s: OOPS! scan cancelled during driver call (1) (ss_iflags=0x%x)!\n",
820 * Record scan complete time. Note that we also do
821 * this when canceled so any background scan will
822 * not be restarted for a while.
825 ic->ic_lastscan = ticks;
826 /* return to the bss channel */
827 if (ic->ic_bsschan != IEEE80211_CHAN_ANYC &&
828 ic->ic_curchan != ic->ic_bsschan) {
829 ieee80211_setupcurchan(ic, ic->ic_bsschan);
830 IEEE80211_UNLOCK(ic);
831 ic->ic_set_channel(ic);
832 ieee80211_radiotap_chan_change(ic);
835 /* clear internal flags and any indication of a pick */
836 ss_priv->ss_iflags &= ~ISCAN_REP;
837 ss->ss_flags &= ~IEEE80211_SCAN_GOTPICK;
840 * If not canceled and scan completed, do post-processing.
841 * If the callback function returns 0, then it wants to
842 * continue/restart scanning. Unfortunately we needed to
843 * notify the driver to end the scan above to avoid having
844 * rx frames alter the scan candidate list.
846 if ((ss_priv->ss_iflags & ISCAN_CANCEL) == 0 &&
847 !ss->ss_ops->scan_end(ss, vap) &&
848 (ss->ss_flags & IEEE80211_SCAN_ONCE) == 0 &&
849 ieee80211_time_before(ticks + ss->ss_mindwell, ss_priv->ss_scanend)) {
850 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
852 "[ticks %u, dwell min %lu scanend %lu]\n",
854 ticks, ss->ss_mindwell, ss_priv->ss_scanend);
855 ss->ss_next = 0; /* reset to beginning */
856 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
857 vap->iv_stats.is_scan_active++;
859 vap->iv_stats.is_scan_passive++;
861 ss->ss_ops->scan_restart(ss, vap); /* XXX? */
862 ieee80211_runtask(ic, &ss_priv->ss_scan_start);
863 IEEE80211_UNLOCK(ic);
867 /* past here, scandone is ``true'' if not in bg mode */
868 if ((ss->ss_flags & IEEE80211_SCAN_BGSCAN) == 0)
871 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
872 "%s: %s, [ticks %u, dwell min %lu scanend %lu]\n",
873 __func__, scandone ? "done" : "stopped",
874 ticks, ss->ss_mindwell, ss_priv->ss_scanend);
877 * Since a cancellation may have occurred during one of the
878 * driver calls (whilst unlocked), update scandone.
880 if (scandone == 0 && (ss_priv->ss_iflags & ISCAN_PAUSE) == ISCAN_CANCEL) {
882 if_printf(vap->iv_ifp,
883 "%s: OOPS! scan cancelled during driver call (2) (ss_iflags=0x%x)!\n",
889 scan_done(ss, scandone);
893 scan_done(struct ieee80211_scan_state *ss, int scandone)
895 struct scan_state *ss_priv = SCAN_PRIVATE(ss);
896 struct ieee80211com *ic = ss->ss_ic;
897 struct ieee80211vap *vap = ss->ss_vap;
899 IEEE80211_LOCK_ASSERT(ic);
902 * Clear the SCAN bit first in case frames are
903 * pending on the station power save queue. If
904 * we defer this then the dispatch of the frames
905 * may generate a request to cancel scanning.
907 ic->ic_flags &= ~IEEE80211_F_SCAN;
910 * Drop out of power save mode when a scan has
911 * completed. If this scan was prematurely terminated
912 * because it is a background scan then don't notify
913 * the ap; we'll either return to scanning after we
914 * receive the beacon frame or we'll drop out of power
915 * save mode because the beacon indicates we have frames
920 * If we're not a scan offload device, come back out of
921 * station powersave. Offload devices handle this themselves.
923 if ((vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) == 0)
924 vap->iv_sta_ps(vap, 0);
925 if (ss->ss_next >= ss->ss_last) {
926 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
927 "%s: Dropping out of scan; ss_next=%u, ss_last=%u\n",
929 (uint32_t) ss->ss_next,
930 (uint32_t) ss->ss_last);
931 ic->ic_flags_ext &= ~IEEE80211_FEXT_BGSCAN;
934 /* send 'scan done' event if not interrupted due to traffic. */
935 if (!(ss_priv->ss_iflags & ISCAN_INTERRUPT) ||
936 (ss->ss_next >= ss->ss_last))
937 ieee80211_notify_scan_done(vap);
939 ss_priv->ss_iflags &= ~(ISCAN_PAUSE | ISCAN_ABORT);
940 ss_priv->ss_scanend = 0;
941 ss->ss_flags &= ~(IEEE80211_SCAN_ONCE | IEEE80211_SCAN_PICK1ST);
942 IEEE80211_UNLOCK(ic);
947 * Process a beacon or probe response frame.
950 ieee80211_swscan_add_scan(struct ieee80211vap *vap,
951 struct ieee80211_channel *curchan,
952 const struct ieee80211_scanparams *sp,
953 const struct ieee80211_frame *wh,
954 int subtype, int rssi, int noise)
956 struct ieee80211com *ic = vap->iv_ic;
957 struct ieee80211_scan_state *ss = ic->ic_scan;
961 * Frames received during startup are discarded to avoid
962 * using scan state setup on the initial entry to the timer
963 * callback. This can occur because the device may enable
964 * rx prior to our doing the initial channel change in the
967 if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_DISCARD)
969 #ifdef IEEE80211_DEBUG
970 if (ieee80211_msg_scan(vap) && (ic->ic_flags & IEEE80211_F_SCAN))
971 ieee80211_scan_dump_probe_beacon(subtype, 1, wh->i_addr2, sp, rssi);
973 if (ss->ss_ops != NULL &&
974 ss->ss_ops->scan_add(ss, curchan, sp, wh, subtype, rssi, noise)) {
976 * If we've reached the min dwell time terminate
977 * the timer so we'll switch to the next channel.
979 if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_MINDWELL) == 0 &&
980 ieee80211_time_after_eq(ticks, SCAN_PRIVATE(ss)->ss_chanmindwell)) {
981 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
982 "%s: chan %3d%c min dwell met (%u > %lu)\n",
984 ieee80211_chan2ieee(ic, ic->ic_curchan),
985 ieee80211_channel_type_char(ic->ic_curchan),
986 ticks, SCAN_PRIVATE(ss)->ss_chanmindwell);
987 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_MINDWELL;
989 * NB: trigger at next clock tick or wait for the
992 ic->ic_scan_mindwell(ss);
997 static struct ieee80211_scan_methods swscan_methods = {
998 .sc_attach = ieee80211_swscan_attach,
999 .sc_detach = ieee80211_swscan_detach,
1000 .sc_vattach = ieee80211_swscan_vattach,
1001 .sc_vdetach = ieee80211_swscan_vdetach,
1002 .sc_set_scan_duration = ieee80211_swscan_set_scan_duration,
1003 .sc_start_scan = ieee80211_swscan_start_scan,
1004 .sc_check_scan = ieee80211_swscan_check_scan,
1005 .sc_bg_scan = ieee80211_swscan_bg_scan,
1006 .sc_cancel_scan = ieee80211_swscan_cancel_scan,
1007 .sc_cancel_anyscan = ieee80211_swscan_cancel_anyscan,
1008 .sc_scan_next = ieee80211_swscan_scan_next,
1009 .sc_scan_done = ieee80211_swscan_scan_done,
1010 .sc_scan_probe_curchan = ieee80211_swscan_probe_curchan,
1011 .sc_add_scan = ieee80211_swscan_add_scan
1015 * Default scan attach method.
1018 ieee80211_swscan_attach(struct ieee80211com *ic)
1020 struct scan_state *ss;
1023 * Setup the default methods
1025 ic->ic_scan_methods = &swscan_methods;
1027 /* Allocate initial scan state */
1028 ss = (struct scan_state *) IEEE80211_MALLOC(sizeof(struct scan_state),
1029 M_80211_SCAN, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
1034 TASK_INIT(&ss->ss_scan_start, 0, scan_start, ss);
1035 TIMEOUT_TASK_INIT(ic->ic_tq, &ss->ss_scan_curchan, 0,
1036 scan_curchan_task, ss);
1038 ic->ic_scan = &ss->base;
1039 ss->base.ss_ic = ic;
1041 ic->ic_scan_curchan = scan_curchan;
1042 ic->ic_scan_mindwell = scan_mindwell;