1 /*-
2 * Copyright (c) 2002-2008 Sam Leffler, Errno Consulting
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD: releng/11.1/sys/net80211/ieee80211_scan_sw.c 300383 2016-05-21 23:21:42Z avos $");
28
29 /*
30 * IEEE 802.11 scanning support.
31 */
32 #include "opt_wlan.h"
33
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/proc.h>
37 #include <sys/kernel.h>
38 #include <sys/malloc.h>
39 #include <sys/condvar.h>
40
41 #include <sys/socket.h>
42
43 #include <net/if.h>
44 #include <net/if_var.h>
45 #include <net/if_media.h>
46 #include <net/ethernet.h>
47
48 #include <net80211/ieee80211_var.h>
49
50 #include <net80211/ieee80211_scan_sw.h>
51
52 #include <net/bpf.h>
53
54 struct scan_state {
55 struct ieee80211_scan_state base; /* public state */
56
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_CANCEL 0x0004 /* cancel current scan */
61 #define ISCAN_ABORT 0x0008 /* end the scan immediately */
62 #define ISCAN_RUNNING 0x0010 /* scan was started */
63
64 unsigned long ss_chanmindwell; /* min dwell on curchan */
65 unsigned long ss_scanend; /* time scan must stop */
66 u_int ss_duration; /* duration for next scan */
67 struct task ss_scan_start; /* scan start */
68 struct timeout_task ss_scan_curchan; /* scan execution */
69 };
70 #define SCAN_PRIVATE(ss) ((struct scan_state *) ss)
71
72 /*
73 * Amount of time to go off-channel during a background
74 * scan. This value should be large enough to catch most
75 * ap's but short enough that we can return on-channel
76 * before our listen interval expires.
77 *
78 * XXX tunable
79 * XXX check against configured listen interval
80 */
81 #define IEEE80211_SCAN_OFFCHANNEL msecs_to_ticks(150)
82
83 static void scan_curchan(struct ieee80211_scan_state *, unsigned long);
84 static void scan_mindwell(struct ieee80211_scan_state *);
85 static void scan_signal(struct ieee80211_scan_state *, int);
86 static void scan_signal_locked(struct ieee80211_scan_state *, int);
87 static void scan_start(void *, int);
88 static void scan_curchan_task(void *, int);
89 static void scan_end(struct ieee80211_scan_state *, int);
90 static void scan_done(struct ieee80211_scan_state *, int);
91
92 MALLOC_DEFINE(M_80211_SCAN, "80211scan", "802.11 scan state");
93
94 static void
95 ieee80211_swscan_detach(struct ieee80211com *ic)
96 {
97 struct ieee80211_scan_state *ss = ic->ic_scan;
98
99 if (ss != NULL) {
100 scan_signal(ss, ISCAN_ABORT);
101 ieee80211_draintask(ic, &SCAN_PRIVATE(ss)->ss_scan_start);
102 taskqueue_drain_timeout(ic->ic_tq,
103 &SCAN_PRIVATE(ss)->ss_scan_curchan);
104 KASSERT((ic->ic_flags & IEEE80211_F_SCAN) == 0,
105 ("scan still running"));
106
107 /*
108 * For now, do the ss_ops detach here rather
109 * than ieee80211_scan_detach().
110 *
111 * I'll figure out how to cleanly split things up
112 * at a later date.
113 */
114 if (ss->ss_ops != NULL) {
115 ss->ss_ops->scan_detach(ss);
116 ss->ss_ops = NULL;
117 }
118 ic->ic_scan = NULL;
119 IEEE80211_FREE(SCAN_PRIVATE(ss), M_80211_SCAN);
120 }
121 }
122
123 static void
124 ieee80211_swscan_vattach(struct ieee80211vap *vap)
125 {
126 /* nothing to do for now */
127 /*
128 * TODO: all of the vap scan calls should be methods!
129 */
130
131 }
132
133 static void
134 ieee80211_swscan_vdetach(struct ieee80211vap *vap)
135 {
136 struct ieee80211com *ic = vap->iv_ic;
137 struct ieee80211_scan_state *ss = ic->ic_scan;
138
139 IEEE80211_LOCK_ASSERT(ic);
140
141 if (ss != NULL && ss->ss_vap == vap &&
142 (ic->ic_flags & IEEE80211_F_SCAN))
143 scan_signal_locked(ss, ISCAN_ABORT);
144 }
145
146 static void
147 ieee80211_swscan_set_scan_duration(struct ieee80211vap *vap, u_int duration)
148 {
149 struct ieee80211com *ic = vap->iv_ic;
150 struct ieee80211_scan_state *ss = ic->ic_scan;
151
152 IEEE80211_LOCK_ASSERT(ic);
153
154 /* NB: flush frames rx'd before 1st channel change */
155 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
156 SCAN_PRIVATE(ss)->ss_duration = duration;
157 }
158
159 /*
160 * Start a scan unless one is already going.
161 */
162 static int
163 ieee80211_swscan_start_scan_locked(const struct ieee80211_scanner *scan,
164 struct ieee80211vap *vap, int flags, u_int duration,
165 u_int mindwell, u_int maxdwell,
166 u_int nssid, const struct ieee80211_scan_ssid ssids[])
167 {
168 struct ieee80211com *ic = vap->iv_ic;
169 struct ieee80211_scan_state *ss = ic->ic_scan;
170
171 IEEE80211_LOCK_ASSERT(ic);
172
173 if (ic->ic_flags & IEEE80211_F_CSAPENDING) {
174 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
175 "%s: scan inhibited by pending channel change\n", __func__);
176 } else if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
177 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
178 "%s: %s scan, duration %u mindwell %u maxdwell %u, desired mode %s, %s%s%s%s%s%s\n"
179 , __func__
180 , flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"
181 , duration, mindwell, maxdwell
182 , ieee80211_phymode_name[vap->iv_des_mode]
183 , flags & IEEE80211_SCAN_FLUSH ? "flush" : "append"
184 , flags & IEEE80211_SCAN_NOPICK ? ", nopick" : ""
185 , flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : ""
186 , flags & IEEE80211_SCAN_NOBCAST ? ", nobcast" : ""
187 , flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : ""
188 , flags & IEEE80211_SCAN_ONCE ? ", once" : ""
189 );
190
191 ieee80211_scan_update_locked(vap, scan);
192 if (ss->ss_ops != NULL) {
193 if ((flags & IEEE80211_SCAN_NOSSID) == 0)
194 ieee80211_scan_copy_ssid(vap, ss, nssid, ssids);
195
196 /* NB: top 4 bits for internal use */
197 ss->ss_flags = flags & 0xfff;
198 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
199 vap->iv_stats.is_scan_active++;
200 else
201 vap->iv_stats.is_scan_passive++;
202 if (flags & IEEE80211_SCAN_FLUSH)
203 ss->ss_ops->scan_flush(ss);
204 if (flags & IEEE80211_SCAN_BGSCAN)
205 ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN;
206
207 /* Set duration for this particular scan */
208 ieee80211_swscan_set_scan_duration(vap, duration);
209
210 ss->ss_next = 0;
211 ss->ss_mindwell = mindwell;
212 ss->ss_maxdwell = maxdwell;
213 /* NB: scan_start must be before the scan runtask */
214 ss->ss_ops->scan_start(ss, vap);
215 #ifdef IEEE80211_DEBUG
216 if (ieee80211_msg_scan(vap))
217 ieee80211_scan_dump(ss);
218 #endif /* IEEE80211_DEBUG */
219 ic->ic_flags |= IEEE80211_F_SCAN;
220
221 /* Start scan task */
222 ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_start);
223 }
224 return 1;
225 } else {
226 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
227 "%s: %s scan already in progress\n", __func__,
228 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
229 }
230 return 0;
231 }
232
233
234 /*
235 * Start a scan unless one is already going.
236 *
237 * Called without the comlock held; grab the comlock as appropriate.
238 */
239 static int
240 ieee80211_swscan_start_scan(const struct ieee80211_scanner *scan,
241 struct ieee80211vap *vap, int flags,
242 u_int duration, u_int mindwell, u_int maxdwell,
243 u_int nssid, const struct ieee80211_scan_ssid ssids[])
244 {
245 struct ieee80211com *ic = vap->iv_ic;
246 int result;
247
248 IEEE80211_UNLOCK_ASSERT(ic);
249
250 IEEE80211_LOCK(ic);
251 result = ieee80211_swscan_start_scan_locked(scan, vap, flags, duration,
252 mindwell, maxdwell, nssid, ssids);
253 IEEE80211_UNLOCK(ic);
254
255 return result;
256 }
257
258 /*
259 * Check the scan cache for an ap/channel to use; if that
260 * fails then kick off a new scan.
261 *
262 * Called with the comlock held.
263 *
264 * XXX TODO: split out!
265 */
266 static int
267 ieee80211_swscan_check_scan(const struct ieee80211_scanner *scan,
268 struct ieee80211vap *vap, int flags,
269 u_int duration, u_int mindwell, u_int maxdwell,
270 u_int nssid, const struct ieee80211_scan_ssid ssids[])
271 {
272 struct ieee80211com *ic = vap->iv_ic;
273 struct ieee80211_scan_state *ss = ic->ic_scan;
274 int result;
275
276 IEEE80211_LOCK_ASSERT(ic);
277
278 if (ss->ss_ops != NULL) {
279 /* XXX verify ss_ops matches vap->iv_opmode */
280 if ((flags & IEEE80211_SCAN_NOSSID) == 0) {
281 /*
282 * Update the ssid list and mark flags so if
283 * we call start_scan it doesn't duplicate work.
284 */
285 ieee80211_scan_copy_ssid(vap, ss, nssid, ssids);
286 flags |= IEEE80211_SCAN_NOSSID;
287 }
288 if ((ic->ic_flags & IEEE80211_F_SCAN) == 0 &&
289 (flags & IEEE80211_SCAN_FLUSH) == 0 &&
290 ieee80211_time_before(ticks, ic->ic_lastscan + vap->iv_scanvalid)) {
291 /*
292 * We're not currently scanning and the cache is
293 * deemed hot enough to consult. Lock out others
294 * by marking IEEE80211_F_SCAN while we decide if
295 * something is already in the scan cache we can
296 * use. Also discard any frames that might come
297 * in while temporarily marked as scanning.
298 */
299 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
300 ic->ic_flags |= IEEE80211_F_SCAN;
301
302 /* NB: need to use supplied flags in check */
303 ss->ss_flags = flags & 0xff;
304 result = ss->ss_ops->scan_end(ss, vap);
305
306 ic->ic_flags &= ~IEEE80211_F_SCAN;
307 SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_DISCARD;
308 if (result) {
309 ieee80211_notify_scan_done(vap);
310 return 1;
311 }
312 }
313 }
314 result = ieee80211_swscan_start_scan_locked(scan, vap, flags, duration,
315 mindwell, maxdwell, nssid, ssids);
316
317 return result;
318 }
319
320 /*
321 * Restart a previous scan. If the previous scan completed
322 * then we start again using the existing channel list.
323 */
324 static int
325 ieee80211_swscan_bg_scan(const struct ieee80211_scanner *scan,
326 struct ieee80211vap *vap, int flags)
327 {
328 struct ieee80211com *ic = vap->iv_ic;
329 struct ieee80211_scan_state *ss = ic->ic_scan;
330
331 /* XXX assert unlocked? */
332 // IEEE80211_UNLOCK_ASSERT(ic);
333
334 IEEE80211_LOCK(ic);
335 if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
336 u_int duration;
337 /*
338 * Go off-channel for a fixed interval that is large
339 * enough to catch most ap's but short enough that
340 * we can return on-channel before our listen interval
341 * expires.
342 */
343 duration = IEEE80211_SCAN_OFFCHANNEL;
344
345 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
346 "%s: %s scan, ticks %u duration %u\n", __func__,
347 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive",
348 ticks, duration);
349
350 ieee80211_scan_update_locked(vap, scan);
351 if (ss->ss_ops != NULL) {
352 ss->ss_vap = vap;
353 /*
354 * A background scan does not select a new sta; it
355 * just refreshes the scan cache. Also, indicate
356 * the scan logic should follow the beacon schedule:
357 * we go off-channel and scan for a while, then
358 * return to the bss channel to receive a beacon,
359 * then go off-channel again. All during this time
360 * we notify the ap we're in power save mode. When
361 * the scan is complete we leave power save mode.
362 * If any beacon indicates there are frames pending
363 * for us then we drop out of power save mode
364 * (and background scan) automatically by way of the
365 * usual sta power save logic.
366 */
367 ss->ss_flags |= IEEE80211_SCAN_NOPICK
368 | IEEE80211_SCAN_BGSCAN
369 | flags
370 ;
371 /* if previous scan completed, restart */
372 if (ss->ss_next >= ss->ss_last) {
373 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
374 vap->iv_stats.is_scan_active++;
375 else
376 vap->iv_stats.is_scan_passive++;
377 /*
378 * NB: beware of the scan cache being flushed;
379 * if the channel list is empty use the
380 * scan_start method to populate it.
381 */
382 ss->ss_next = 0;
383 if (ss->ss_last != 0)
384 ss->ss_ops->scan_restart(ss, vap);
385 else {
386 ss->ss_ops->scan_start(ss, vap);
387 #ifdef IEEE80211_DEBUG
388 if (ieee80211_msg_scan(vap))
389 ieee80211_scan_dump(ss);
390 #endif /* IEEE80211_DEBUG */
391 }
392 }
393 ieee80211_swscan_set_scan_duration(vap, duration);
394 ss->ss_maxdwell = duration;
395 ic->ic_flags |= IEEE80211_F_SCAN;
396 ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN;
397 ieee80211_runtask(ic,
398 &SCAN_PRIVATE(ss)->ss_scan_start);
399 } else {
400 /* XXX msg+stat */
401 }
402 } else {
403 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
404 "%s: %s scan already in progress\n", __func__,
405 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
406 }
407 IEEE80211_UNLOCK(ic);
408
409 /* NB: racey, does it matter? */
410 return (ic->ic_flags & IEEE80211_F_SCAN);
411 }
412
413 static void
414 cancel_scan(struct ieee80211vap *vap, int any, const char *func)
415 {
416 struct ieee80211com *ic = vap->iv_ic;
417 struct ieee80211_scan_state *ss = ic->ic_scan;
418
419 IEEE80211_LOCK(ic);
420 if ((ic->ic_flags & IEEE80211_F_SCAN) &&
421 (any || ss->ss_vap == vap) &&
422 (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0) {
423 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
424 "%s: cancel %s scan\n", func,
425 ss->ss_flags & IEEE80211_SCAN_ACTIVE ?
426 "active" : "passive");
427
428 /* clear bg scan NOPICK */
429 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
430 /* mark cancel request and wake up the scan task */
431 scan_signal_locked(ss, ISCAN_CANCEL);
432 } else {
433 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
434 "%s: called; F_SCAN=%d, vap=%s, CANCEL=%d\n",
435 func,
436 !! (ic->ic_flags & IEEE80211_F_SCAN),
437 (ss->ss_vap == vap ? "match" : "nomatch"),
438 !! (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL));
439 }
440 IEEE80211_UNLOCK(ic);
441 }
442
443 /*
444 * Cancel any scan currently going on for the specified vap.
445 */
446 static void
447 ieee80211_swscan_cancel_scan(struct ieee80211vap *vap)
448 {
449 cancel_scan(vap, 0, __func__);
450 }
451
452 /*
453 * Cancel any scan currently going on.
454 */
455 static void
456 ieee80211_swscan_cancel_anyscan(struct ieee80211vap *vap)
457 {
458 cancel_scan(vap, 1, __func__);
459 }
460
461 /*
462 * Manually switch to the next channel in the channel list.
463 * Provided for drivers that manage scanning themselves
464 * (e.g. for firmware-based devices).
465 */
466 static void
467 ieee80211_swscan_scan_next(struct ieee80211vap *vap)
468 {
469 struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
470
471 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: called\n", __func__);
472
473 /* wake up the scan task */
474 scan_signal(ss, 0);
475 }
476
477 /*
478 * Manually stop a scan that is currently running.
479 * Provided for drivers that are not able to scan single channels
480 * (e.g. for firmware-based devices).
481 */
482 static void
483 ieee80211_swscan_scan_done(struct ieee80211vap *vap)
484 {
485 struct ieee80211com *ic = vap->iv_ic;
486 struct ieee80211_scan_state *ss = ic->ic_scan;
487
488 IEEE80211_LOCK_ASSERT(ic);
489
490 scan_signal_locked(ss, 0);
491 }
492
493 /*
494 * Probe the current channel, if allowed, while scanning.
495 * If the channel is not marked passive-only then send
496 * a probe request immediately. Otherwise mark state and
497 * listen for beacons on the channel; if we receive something
498 * then we'll transmit a probe request.
499 */
500 static void
501 ieee80211_swscan_probe_curchan(struct ieee80211vap *vap, int force)
502 {
503 struct ieee80211com *ic = vap->iv_ic;
504 struct ieee80211_scan_state *ss = ic->ic_scan;
505 struct ifnet *ifp = vap->iv_ifp;
506 int i;
507
508 /*
509 * Send directed probe requests followed by any
510 * broadcast probe request.
511 * XXX remove dependence on ic/vap->iv_bss
512 */
513 for (i = 0; i < ss->ss_nssid; i++)
514 ieee80211_send_probereq(vap->iv_bss,
515 vap->iv_myaddr, ifp->if_broadcastaddr,
516 ifp->if_broadcastaddr,
517 ss->ss_ssid[i].ssid, ss->ss_ssid[i].len);
518 if ((ss->ss_flags & IEEE80211_SCAN_NOBCAST) == 0)
519 ieee80211_send_probereq(vap->iv_bss,
520 vap->iv_myaddr, ifp->if_broadcastaddr,
521 ifp->if_broadcastaddr,
522 "", 0);
523 }
524
525 /*
526 * Scan curchan. If this is an active scan and the channel
527 * is not marked passive then send probe request frame(s).
528 * Arrange for the channel change after maxdwell ticks.
529 */
530 static void
531 scan_curchan(struct ieee80211_scan_state *ss, unsigned long maxdwell)
532 {
533 struct ieee80211vap *vap = ss->ss_vap;
534 struct ieee80211com *ic = ss->ss_ic;
535
536 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
537 "%s: calling; maxdwell=%lu\n",
538 __func__,
539 maxdwell);
540 IEEE80211_LOCK(ic);
541 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
542 ieee80211_probe_curchan(vap, 0);
543 taskqueue_enqueue_timeout(ic->ic_tq,
544 &SCAN_PRIVATE(ss)->ss_scan_curchan, maxdwell);
545 IEEE80211_UNLOCK(ic);
546 }
547
548 static void
549 scan_signal(struct ieee80211_scan_state *ss, int iflags)
550 {
551 struct ieee80211com *ic = ss->ss_ic;
552
553 IEEE80211_UNLOCK_ASSERT(ic);
554
555 IEEE80211_LOCK(ic);
556 scan_signal_locked(ss, iflags);
557 IEEE80211_UNLOCK(ic);
558 }
559
560 static void
561 scan_signal_locked(struct ieee80211_scan_state *ss, int iflags)
562 {
563 struct scan_state *ss_priv = SCAN_PRIVATE(ss);
564 struct timeout_task *scan_task = &ss_priv->ss_scan_curchan;
565 struct ieee80211com *ic = ss->ss_ic;
566
567 IEEE80211_LOCK_ASSERT(ic);
568
569 ss_priv->ss_iflags |= iflags;
570 if (ss_priv->ss_iflags & ISCAN_RUNNING) {
571 if (taskqueue_cancel_timeout(ic->ic_tq, scan_task, NULL) == 0)
572 taskqueue_enqueue_timeout(ic->ic_tq, scan_task, 0);
573 }
574 }
575
576 /*
577 * Handle mindwell requirements completed; initiate a channel
578 * change to the next channel asap.
579 */
580 static void
581 scan_mindwell(struct ieee80211_scan_state *ss)
582 {
583
584 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, "%s: called\n",
585 __func__);
586
587 scan_signal(ss, 0);
588 }
589
590 static void
591 scan_start(void *arg, int pending)
592 {
593 #define ISCAN_REP (ISCAN_MINDWELL | ISCAN_DISCARD)
594 struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg;
595 struct scan_state *ss_priv = SCAN_PRIVATE(ss);
596 struct ieee80211vap *vap = ss->ss_vap;
597 struct ieee80211com *ic = ss->ss_ic;
598
599 IEEE80211_LOCK(ic);
600 if (vap == NULL || (ic->ic_flags & IEEE80211_F_SCAN) == 0 ||
601 (ss_priv->ss_iflags & ISCAN_ABORT)) {
602 /* Cancelled before we started */
603 scan_done(ss, 0);
604 return;
605 }
606
607 if (ss->ss_next == ss->ss_last) {
608 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
609 "%s: no channels to scan\n", __func__);
610 scan_done(ss, 1);
611 return;
612 }
613
614 if (vap->iv_opmode == IEEE80211_M_STA &&
615 vap->iv_state == IEEE80211_S_RUN) {
616 if ((vap->iv_bss->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) {
617 /* Enable station power save mode */
618 vap->iv_sta_ps(vap, 1);
619 /* Wait until null data frame will be ACK'ed */
620 mtx_sleep(vap, IEEE80211_LOCK_OBJ(ic), PCATCH,
621 "sta_ps", msecs_to_ticks(10));
622 if (ss_priv->ss_iflags & ISCAN_ABORT) {
623 scan_done(ss, 0);
624 return;
625 }
626 }
627 }
628
629 ss_priv->ss_scanend = ticks + ss_priv->ss_duration;
630
631 /* XXX scan state can change! Re-validate scan state! */
632
633 IEEE80211_UNLOCK(ic);
634
635 ic->ic_scan_start(ic); /* notify driver */
636
637 scan_curchan_task(ss, 0);
638 }
639
640 static void
641 scan_curchan_task(void *arg, int pending)
642 {
643 struct ieee80211_scan_state *ss = arg;
644 struct scan_state *ss_priv = SCAN_PRIVATE(ss);
645 struct ieee80211com *ic = ss->ss_ic;
646 struct ieee80211_channel *chan;
647 unsigned long maxdwell;
648 int scandone;
649
650 IEEE80211_LOCK(ic);
651 end:
652 scandone = (ss->ss_next >= ss->ss_last) ||
653 (ss_priv->ss_iflags & ISCAN_CANCEL) != 0;
654
655 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN,
656 "%s: loop start; scandone=%d\n",
657 __func__,
658 scandone);
659
660 if (scandone || (ss->ss_flags & IEEE80211_SCAN_GOTPICK) ||
661 (ss_priv->ss_iflags & ISCAN_ABORT) ||
662 ieee80211_time_after(ticks + ss->ss_mindwell, ss_priv->ss_scanend)) {
663 ss_priv->ss_iflags &= ~ISCAN_RUNNING;
664 scan_end(ss, scandone);
665 return;
666 } else
667 ss_priv->ss_iflags |= ISCAN_RUNNING;
668
669 chan = ss->ss_chans[ss->ss_next++];
670
671 /*
672 * Watch for truncation due to the scan end time.
673 */
674 if (ieee80211_time_after(ticks + ss->ss_maxdwell, ss_priv->ss_scanend))
675 maxdwell = ss_priv->ss_scanend - ticks;
676 else
677 maxdwell = ss->ss_maxdwell;
678
679 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN,
680 "%s: chan %3d%c -> %3d%c [%s, dwell min %lums max %lums]\n",
681 __func__,
682 ieee80211_chan2ieee(ic, ic->ic_curchan),
683 ieee80211_channel_type_char(ic->ic_curchan),
684 ieee80211_chan2ieee(ic, chan),
685 ieee80211_channel_type_char(chan),
686 (ss->ss_flags & IEEE80211_SCAN_ACTIVE) &&
687 (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0 ?
688 "active" : "passive",
689 ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(maxdwell));
690
691 /*
692 * Potentially change channel and phy mode.
693 */
694 ic->ic_curchan = chan;
695 ic->ic_rt = ieee80211_get_ratetable(chan);
696 IEEE80211_UNLOCK(ic);
697 /*
698 * Perform the channel change and scan unlocked so the driver
699 * may sleep. Once set_channel returns the hardware has
700 * completed the channel change.
701 */
702 ic->ic_set_channel(ic);
703 ieee80211_radiotap_chan_change(ic);
704
705 /*
706 * Scan curchan. Drivers for "intelligent hardware"
707 * override ic_scan_curchan to tell the device to do
708 * the work. Otherwise we manage the work ourselves;
709 * sending a probe request (as needed), and arming the
710 * timeout to switch channels after maxdwell ticks.
711 *
712 * scan_curchan should only pause for the time required to
713 * prepare/initiate the hardware for the scan (if at all).
714 */
715 ic->ic_scan_curchan(ss, maxdwell);
716 IEEE80211_LOCK(ic);
717
718 /* XXX scan state can change! Re-validate scan state! */
719
720 ss_priv->ss_chanmindwell = ticks + ss->ss_mindwell;
721 /* clear mindwell lock and initial channel change flush */
722 ss_priv->ss_iflags &= ~ISCAN_REP;
723
724 if (ss_priv->ss_iflags & (ISCAN_CANCEL|ISCAN_ABORT)) {
725 taskqueue_cancel_timeout(ic->ic_tq, &ss_priv->ss_scan_curchan,
726 NULL);
727 goto end;
728 }
729
730 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, "%s: waiting\n",
731 __func__);
732 IEEE80211_UNLOCK(ic);
733 }
734
735 static void
736 scan_end(struct ieee80211_scan_state *ss, int scandone)
737 {
738 struct scan_state *ss_priv = SCAN_PRIVATE(ss);
739 struct ieee80211vap *vap = ss->ss_vap;
740 struct ieee80211com *ic = ss->ss_ic;
741
742 IEEE80211_LOCK_ASSERT(ic);
743
744 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: out\n", __func__);
745
746 if (ss_priv->ss_iflags & ISCAN_ABORT) {
747 scan_done(ss, scandone);
748 return;
749 }
750
751 IEEE80211_UNLOCK(ic);
752 ic->ic_scan_end(ic); /* notify driver */
753 IEEE80211_LOCK(ic);
754 /* XXX scan state can change! Re-validate scan state! */
755
756 /*
757 * Since a cancellation may have occurred during one of the
758 * driver calls (whilst unlocked), update scandone.
759 */
760 if (scandone == 0 && (ss_priv->ss_iflags & ISCAN_CANCEL) != 0) {
761 /* XXX printf? */
762 if_printf(vap->iv_ifp,
763 "%s: OOPS! scan cancelled during driver call (1)!\n",
764 __func__);
765 scandone = 1;
766 }
767
768 /*
769 * Record scan complete time. Note that we also do
770 * this when canceled so any background scan will
771 * not be restarted for a while.
772 */
773 if (scandone)
774 ic->ic_lastscan = ticks;
775 /* return to the bss channel */
776 if (ic->ic_bsschan != IEEE80211_CHAN_ANYC &&
777 ic->ic_curchan != ic->ic_bsschan) {
778 ieee80211_setupcurchan(ic, ic->ic_bsschan);
779 IEEE80211_UNLOCK(ic);
780 ic->ic_set_channel(ic);
781 ieee80211_radiotap_chan_change(ic);
782 IEEE80211_LOCK(ic);
783 }
784 /* clear internal flags and any indication of a pick */
785 ss_priv->ss_iflags &= ~ISCAN_REP;
786 ss->ss_flags &= ~IEEE80211_SCAN_GOTPICK;
787
788 /*
789 * If not canceled and scan completed, do post-processing.
790 * If the callback function returns 0, then it wants to
791 * continue/restart scanning. Unfortunately we needed to
792 * notify the driver to end the scan above to avoid having
793 * rx frames alter the scan candidate list.
794 */
795 if ((ss_priv->ss_iflags & ISCAN_CANCEL) == 0 &&
796 !ss->ss_ops->scan_end(ss, vap) &&
797 (ss->ss_flags & IEEE80211_SCAN_ONCE) == 0 &&
798 ieee80211_time_before(ticks + ss->ss_mindwell, ss_priv->ss_scanend)) {
799 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
800 "%s: done, restart "
801 "[ticks %u, dwell min %lu scanend %lu]\n",
802 __func__,
803 ticks, ss->ss_mindwell, ss_priv->ss_scanend);
804 ss->ss_next = 0; /* reset to beginning */
805 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
806 vap->iv_stats.is_scan_active++;
807 else
808 vap->iv_stats.is_scan_passive++;
809
810 ss->ss_ops->scan_restart(ss, vap); /* XXX? */
811 ieee80211_runtask(ic, &ss_priv->ss_scan_start);
812 IEEE80211_UNLOCK(ic);
813 return;
814 }
815
816 /* past here, scandone is ``true'' if not in bg mode */
817 if ((ss->ss_flags & IEEE80211_SCAN_BGSCAN) == 0)
818 scandone = 1;
819
820 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
821 "%s: %s, [ticks %u, dwell min %lu scanend %lu]\n",
822 __func__, scandone ? "done" : "stopped",
823 ticks, ss->ss_mindwell, ss_priv->ss_scanend);
824
825 /*
826 * Since a cancellation may have occurred during one of the
827 * driver calls (whilst unlocked), update scandone.
828 */
829 if (scandone == 0 && (ss_priv->ss_iflags & ISCAN_CANCEL) != 0) {
830 /* XXX printf? */
831 if_printf(vap->iv_ifp,
832 "%s: OOPS! scan cancelled during driver call (2)!\n",
833 __func__);
834 scandone = 1;
835 }
836
837 scan_done(ss, scandone);
838 }
839
840 static void
841 scan_done(struct ieee80211_scan_state *ss, int scandone)
842 {
843 struct scan_state *ss_priv = SCAN_PRIVATE(ss);
844 struct ieee80211com *ic = ss->ss_ic;
845 struct ieee80211vap *vap = ss->ss_vap;
846
847 IEEE80211_LOCK_ASSERT(ic);
848
849 /*
850 * Clear the SCAN bit first in case frames are
851 * pending on the station power save queue. If
852 * we defer this then the dispatch of the frames
853 * may generate a request to cancel scanning.
854 */
855 ic->ic_flags &= ~IEEE80211_F_SCAN;
856
857 /*
858 * Drop out of power save mode when a scan has
859 * completed. If this scan was prematurely terminated
860 * because it is a background scan then don't notify
861 * the ap; we'll either return to scanning after we
862 * receive the beacon frame or we'll drop out of power
863 * save mode because the beacon indicates we have frames
864 * waiting for us.
865 */
866 if (scandone) {
867 vap->iv_sta_ps(vap, 0);
868 if (ss->ss_next >= ss->ss_last)
869 ic->ic_flags_ext &= ~IEEE80211_FEXT_BGSCAN;
870
871 ieee80211_notify_scan_done(vap);
872 }
873 ss_priv->ss_iflags &= ~(ISCAN_CANCEL|ISCAN_ABORT);
874 ss_priv->ss_scanend = 0;
875 ss->ss_flags &= ~(IEEE80211_SCAN_ONCE | IEEE80211_SCAN_PICK1ST);
876 IEEE80211_UNLOCK(ic);
877 #undef ISCAN_REP
878 }
879
880 /*
881 * Process a beacon or probe response frame.
882 */
883 static void
884 ieee80211_swscan_add_scan(struct ieee80211vap *vap,
885 struct ieee80211_channel *curchan,
886 const struct ieee80211_scanparams *sp,
887 const struct ieee80211_frame *wh,
888 int subtype, int rssi, int noise)
889 {
890 struct ieee80211com *ic = vap->iv_ic;
891 struct ieee80211_scan_state *ss = ic->ic_scan;
892
893 /* XXX locking */
894 /*
895 * Frames received during startup are discarded to avoid
896 * using scan state setup on the initial entry to the timer
897 * callback. This can occur because the device may enable
898 * rx prior to our doing the initial channel change in the
899 * timer routine.
900 */
901 if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_DISCARD)
902 return;
903 #ifdef IEEE80211_DEBUG
904 if (ieee80211_msg_scan(vap) && (ic->ic_flags & IEEE80211_F_SCAN))
905 ieee80211_scan_dump_probe_beacon(subtype, 1, wh->i_addr2, sp, rssi);
906 #endif
907 if (ss->ss_ops != NULL &&
908 ss->ss_ops->scan_add(ss, curchan, sp, wh, subtype, rssi, noise)) {
909 /*
910 * If we've reached the min dwell time terminate
911 * the timer so we'll switch to the next channel.
912 */
913 if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_MINDWELL) == 0 &&
914 ieee80211_time_after_eq(ticks, SCAN_PRIVATE(ss)->ss_chanmindwell)) {
915 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
916 "%s: chan %3d%c min dwell met (%u > %lu)\n",
917 __func__,
918 ieee80211_chan2ieee(ic, ic->ic_curchan),
919 ieee80211_channel_type_char(ic->ic_curchan),
920 ticks, SCAN_PRIVATE(ss)->ss_chanmindwell);
921 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_MINDWELL;
922 /*
923 * NB: trigger at next clock tick or wait for the
924 * hardware.
925 */
926 ic->ic_scan_mindwell(ss);
927 }
928 }
929 }
930
931 static struct ieee80211_scan_methods swscan_methods = {
932 .sc_attach = ieee80211_swscan_attach,
933 .sc_detach = ieee80211_swscan_detach,
934 .sc_vattach = ieee80211_swscan_vattach,
935 .sc_vdetach = ieee80211_swscan_vdetach,
936 .sc_set_scan_duration = ieee80211_swscan_set_scan_duration,
937 .sc_start_scan = ieee80211_swscan_start_scan,
938 .sc_check_scan = ieee80211_swscan_check_scan,
939 .sc_bg_scan = ieee80211_swscan_bg_scan,
940 .sc_cancel_scan = ieee80211_swscan_cancel_scan,
941 .sc_cancel_anyscan = ieee80211_swscan_cancel_anyscan,
942 .sc_scan_next = ieee80211_swscan_scan_next,
943 .sc_scan_done = ieee80211_swscan_scan_done,
944 .sc_scan_probe_curchan = ieee80211_swscan_probe_curchan,
945 .sc_add_scan = ieee80211_swscan_add_scan
946 };
947
948 /*
949 * Default scan attach method.
950 */
951 void
952 ieee80211_swscan_attach(struct ieee80211com *ic)
953 {
954 struct scan_state *ss;
955
956 /*
957 * Setup the default methods
958 */
959 ic->ic_scan_methods = &swscan_methods;
960
961 /* Allocate initial scan state */
962 ss = (struct scan_state *) IEEE80211_MALLOC(sizeof(struct scan_state),
963 M_80211_SCAN, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
964 if (ss == NULL) {
965 ic->ic_scan = NULL;
966 return;
967 }
968 TASK_INIT(&ss->ss_scan_start, 0, scan_start, ss);
969 TIMEOUT_TASK_INIT(ic->ic_tq, &ss->ss_scan_curchan, 0,
970 scan_curchan_task, ss);
971
972 ic->ic_scan = &ss->base;
973 ss->base.ss_ic = ic;
974
975 ic->ic_scan_curchan = scan_curchan;
976 ic->ic_scan_mindwell = scan_mindwell;
977 }
Cache object: c4c56c5a4529edd57d3ffba010927d34
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