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net/mlx4_core: Fix leakage of SW multicast entries
[linux-2.6/btrfs-unstable.git] / net / mac80211 / scan.c
bloba0a938145dcc87397cb4ecfad5f59b1c5fb28dbc
1 /*
2 * Scanning implementation
3 *
4 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
5 * Copyright 2004, Instant802 Networks, Inc.
6 * Copyright 2005, Devicescape Software, Inc.
7 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
8 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 */
14
15 #include <linux/if_arp.h>
16 #include <linux/etherdevice.h>
17 #include <linux/rtnetlink.h>
18 #include <linux/pm_qos.h>
19 #include <net/sch_generic.h>
20 #include <linux/slab.h>
21 #include <linux/export.h>
22 #include <net/mac80211.h>
23
24 #include "ieee80211_i.h"
25 #include "driver-ops.h"
26 #include "mesh.h"
27
28 #define IEEE80211_PROBE_DELAY (HZ / 33)
29 #define IEEE80211_CHANNEL_TIME (HZ / 33)
30 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
31
32 void ieee80211_rx_bss_put(struct ieee80211_local *local,
33 struct ieee80211_bss *bss)
34 {
35 if (!bss)
36 return;
37 cfg80211_put_bss(local->hw.wiphy,
38 container_of((void *)bss, struct cfg80211_bss, priv));
39 }
40
41 static bool is_uapsd_supported(struct ieee802_11_elems *elems)
42 {
43 u8 qos_info;
44
45 if (elems->wmm_info && elems->wmm_info_len == 7
46 && elems->wmm_info[5] == 1)
47 qos_info = elems->wmm_info[6];
48 else if (elems->wmm_param && elems->wmm_param_len == 24
49 && elems->wmm_param[5] == 1)
50 qos_info = elems->wmm_param[6];
51 else
52 /* no valid wmm information or parameter element found */
53 return false;
54
55 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
56 }
57
58 struct ieee80211_bss *
59 ieee80211_bss_info_update(struct ieee80211_local *local,
60 struct ieee80211_rx_status *rx_status,
61 struct ieee80211_mgmt *mgmt, size_t len,
62 struct ieee802_11_elems *elems,
63 struct ieee80211_channel *channel)
64 {
65 bool beacon = ieee80211_is_beacon(mgmt->frame_control);
66 struct cfg80211_bss *cbss;
67 struct ieee80211_bss *bss;
68 int clen, srlen;
69 enum nl80211_bss_scan_width scan_width;
70 s32 signal = 0;
71
72 if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
73 signal = rx_status->signal * 100;
74 else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC)
75 signal = (rx_status->signal * 100) / local->hw.max_signal;
76
77 scan_width = NL80211_BSS_CHAN_WIDTH_20;
78 if (rx_status->flag & RX_FLAG_5MHZ)
79 scan_width = NL80211_BSS_CHAN_WIDTH_5;
80 if (rx_status->flag & RX_FLAG_10MHZ)
81 scan_width = NL80211_BSS_CHAN_WIDTH_10;
82
83 cbss = cfg80211_inform_bss_width_frame(local->hw.wiphy, channel,
84 scan_width, mgmt, len, signal,
85 GFP_ATOMIC);
86 if (!cbss)
87 return NULL;
88
89 bss = (void *)cbss->priv;
90
91 if (beacon)
92 bss->device_ts_beacon = rx_status->device_timestamp;
93 else
94 bss->device_ts_presp = rx_status->device_timestamp;
95
96 if (elems->parse_error) {
97 if (beacon)
98 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
99 else
100 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
101 } else {
102 if (beacon)
103 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
104 else
105 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
106 }
107
108 /* save the ERP value so that it is available at association time */
109 if (elems->erp_info && (!elems->parse_error ||
110 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
111 bss->erp_value = elems->erp_info[0];
112 bss->has_erp_value = true;
113 if (!elems->parse_error)
114 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
115 }
116
117 /* replace old supported rates if we get new values */
118 if (!elems->parse_error ||
119 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
120 srlen = 0;
121 if (elems->supp_rates) {
122 clen = IEEE80211_MAX_SUPP_RATES;
123 if (clen > elems->supp_rates_len)
124 clen = elems->supp_rates_len;
125 memcpy(bss->supp_rates, elems->supp_rates, clen);
126 srlen += clen;
127 }
128 if (elems->ext_supp_rates) {
129 clen = IEEE80211_MAX_SUPP_RATES - srlen;
130 if (clen > elems->ext_supp_rates_len)
131 clen = elems->ext_supp_rates_len;
132 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
133 clen);
134 srlen += clen;
135 }
136 if (srlen) {
137 bss->supp_rates_len = srlen;
138 if (!elems->parse_error)
139 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
140 }
141 }
142
143 if (!elems->parse_error ||
144 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
145 bss->wmm_used = elems->wmm_param || elems->wmm_info;
146 bss->uapsd_supported = is_uapsd_supported(elems);
147 if (!elems->parse_error)
148 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
149 }
150
151 if (beacon) {
152 struct ieee80211_supported_band *sband =
153 local->hw.wiphy->bands[rx_status->band];
154 if (!(rx_status->flag & RX_FLAG_HT) &&
155 !(rx_status->flag & RX_FLAG_VHT))
156 bss->beacon_rate =
157 &sband->bitrates[rx_status->rate_idx];
158 }
159
160 return bss;
161 }
162
163 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
164 {
165 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
166 struct ieee80211_sub_if_data *sdata1, *sdata2;
167 struct ieee80211_mgmt *mgmt = (void *)skb->data;
168 struct ieee80211_bss *bss;
169 u8 *elements;
170 struct ieee80211_channel *channel;
171 size_t baselen;
172 struct ieee802_11_elems elems;
173
174 if (skb->len < 24 ||
175 (!ieee80211_is_probe_resp(mgmt->frame_control) &&
176 !ieee80211_is_beacon(mgmt->frame_control)))
177 return;
178
179 sdata1 = rcu_dereference(local->scan_sdata);
180 sdata2 = rcu_dereference(local->sched_scan_sdata);
181
182 if (likely(!sdata1 && !sdata2))
183 return;
184
185 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
186 /* ignore ProbeResp to foreign address */
187 if ((!sdata1 || !ether_addr_equal(mgmt->da, sdata1->vif.addr)) &&
188 (!sdata2 || !ether_addr_equal(mgmt->da, sdata2->vif.addr)))
189 return;
190
191 elements = mgmt->u.probe_resp.variable;
192 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
193 } else {
194 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
195 elements = mgmt->u.beacon.variable;
196 }
197
198 if (baselen > skb->len)
199 return;
200
201 ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems);
202
203 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
204
205 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
206 return;
207
208 bss = ieee80211_bss_info_update(local, rx_status,
209 mgmt, skb->len, &elems,
210 channel);
211 if (bss)
212 ieee80211_rx_bss_put(local, bss);
213 }
214
215 static void
216 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
217 enum nl80211_bss_scan_width scan_width)
218 {
219 memset(chandef, 0, sizeof(*chandef));
220 switch (scan_width) {
221 case NL80211_BSS_CHAN_WIDTH_5:
222 chandef->width = NL80211_CHAN_WIDTH_5;
223 break;
224 case NL80211_BSS_CHAN_WIDTH_10:
225 chandef->width = NL80211_CHAN_WIDTH_10;
226 break;
227 default:
228 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
229 break;
230 }
231 }
232
233 /* return false if no more work */
234 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
235 {
236 struct cfg80211_scan_request *req = local->scan_req;
237 struct cfg80211_chan_def chandef;
238 u8 bands_used = 0;
239 int i, ielen, n_chans;
240
241 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
242 return false;
243
244 if (local->hw.flags & IEEE80211_SINGLE_HW_SCAN_ON_ALL_BANDS) {
245 for (i = 0; i < req->n_channels; i++) {
246 local->hw_scan_req->req.channels[i] = req->channels[i];
247 bands_used |= BIT(req->channels[i]->band);
248 }
249
250 n_chans = req->n_channels;
251 } else {
252 do {
253 if (local->hw_scan_band == IEEE80211_NUM_BANDS)
254 return false;
255
256 n_chans = 0;
257
258 for (i = 0; i < req->n_channels; i++) {
259 if (req->channels[i]->band !=
260 local->hw_scan_band)
261 continue;
262 local->hw_scan_req->req.channels[n_chans] =
263 req->channels[i];
264 n_chans++;
265 bands_used |= BIT(req->channels[i]->band);
266 }
267
268 local->hw_scan_band++;
269 } while (!n_chans);
270 }
271
272 local->hw_scan_req->req.n_channels = n_chans;
273 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
274
275 ielen = ieee80211_build_preq_ies(local,
276 (u8 *)local->hw_scan_req->req.ie,
277 local->hw_scan_ies_bufsize,
278 &local->hw_scan_req->ies,
279 req->ie, req->ie_len,
280 bands_used, req->rates, &chandef);
281 local->hw_scan_req->req.ie_len = ielen;
282 local->hw_scan_req->req.no_cck = req->no_cck;
283
284 return true;
285 }
286
287 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
288 {
289 struct ieee80211_local *local = hw_to_local(hw);
290 bool hw_scan = local->ops->hw_scan;
291 bool was_scanning = local->scanning;
292
293 lockdep_assert_held(&local->mtx);
294
295 /*
296 * It's ok to abort a not-yet-running scan (that
297 * we have one at all will be verified by checking
298 * local->scan_req next), but not to complete it
299 * successfully.
300 */
301 if (WARN_ON(!local->scanning && !aborted))
302 aborted = true;
303
304 if (WARN_ON(!local->scan_req))
305 return;
306
307 if (hw_scan && !aborted &&
308 !(local->hw.flags & IEEE80211_SINGLE_HW_SCAN_ON_ALL_BANDS) &&
309 ieee80211_prep_hw_scan(local)) {
310 int rc;
311
312 rc = drv_hw_scan(local,
313 rcu_dereference_protected(local->scan_sdata,
314 lockdep_is_held(&local->mtx)),
315 local->hw_scan_req);
316
317 if (rc == 0)
318 return;
319 }
320
321 kfree(local->hw_scan_req);
322 local->hw_scan_req = NULL;
323
324 if (local->scan_req != local->int_scan_req)
325 cfg80211_scan_done(local->scan_req, aborted);
326 local->scan_req = NULL;
327 RCU_INIT_POINTER(local->scan_sdata, NULL);
328
329 local->scanning = 0;
330 local->scan_chandef.chan = NULL;
331
332 /* Set power back to normal operating levels. */
333 ieee80211_hw_config(local, 0);
334
335 if (!hw_scan) {
336 ieee80211_configure_filter(local);
337 drv_sw_scan_complete(local);
338 ieee80211_offchannel_return(local);
339 }
340
341 ieee80211_recalc_idle(local);
342
343 ieee80211_mlme_notify_scan_completed(local);
344 ieee80211_ibss_notify_scan_completed(local);
345 ieee80211_mesh_notify_scan_completed(local);
346 if (was_scanning)
347 ieee80211_start_next_roc(local);
348 }
349
350 void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
351 {
352 struct ieee80211_local *local = hw_to_local(hw);
353
354 trace_api_scan_completed(local, aborted);
355
356 set_bit(SCAN_COMPLETED, &local->scanning);
357 if (aborted)
358 set_bit(SCAN_ABORTED, &local->scanning);
359 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
360 }
361 EXPORT_SYMBOL(ieee80211_scan_completed);
362
363 static int ieee80211_start_sw_scan(struct ieee80211_local *local)
364 {
365 /* Software scan is not supported in multi-channel cases */
366 if (local->use_chanctx)
367 return -EOPNOTSUPP;
368
369 /*
370 * Hardware/driver doesn't support hw_scan, so use software
371 * scanning instead. First send a nullfunc frame with power save
372 * bit on so that AP will buffer the frames for us while we are not
373 * listening, then send probe requests to each channel and wait for
374 * the responses. After all channels are scanned, tune back to the
375 * original channel and send a nullfunc frame with power save bit
376 * off to trigger the AP to send us all the buffered frames.
377 *
378 * Note that while local->sw_scanning is true everything else but
379 * nullfunc frames and probe requests will be dropped in
380 * ieee80211_tx_h_check_assoc().
381 */
382 drv_sw_scan_start(local);
383
384 local->leave_oper_channel_time = jiffies;
385 local->next_scan_state = SCAN_DECISION;
386 local->scan_channel_idx = 0;
387
388 ieee80211_offchannel_stop_vifs(local);
389
390 /* ensure nullfunc is transmitted before leaving operating channel */
391 ieee80211_flush_queues(local, NULL);
392
393 ieee80211_configure_filter(local);
394
395 /* We need to set power level at maximum rate for scanning. */
396 ieee80211_hw_config(local, 0);
397
398 ieee80211_queue_delayed_work(&local->hw,
399 &local->scan_work, 0);
400
401 return 0;
402 }
403
404 static bool ieee80211_can_scan(struct ieee80211_local *local,
405 struct ieee80211_sub_if_data *sdata)
406 {
407 if (local->radar_detect_enabled)
408 return false;
409
410 if (!list_empty(&local->roc_list))
411 return false;
412
413 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
414 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
415 return false;
416
417 return true;
418 }
419
420 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
421 {
422 lockdep_assert_held(&local->mtx);
423
424 if (!local->scan_req || local->scanning)
425 return;
426
427 if (!ieee80211_can_scan(local,
428 rcu_dereference_protected(
429 local->scan_sdata,
430 lockdep_is_held(&local->mtx))))
431 return;
432
433 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
434 round_jiffies_relative(0));
435 }
436
437 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
438 unsigned long *next_delay)
439 {
440 int i;
441 struct ieee80211_sub_if_data *sdata;
442 enum ieee80211_band band = local->hw.conf.chandef.chan->band;
443 u32 tx_flags;
444
445 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
446 if (local->scan_req->no_cck)
447 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
448
449 sdata = rcu_dereference_protected(local->scan_sdata,
450 lockdep_is_held(&local->mtx));
451
452 for (i = 0; i < local->scan_req->n_ssids; i++)
453 ieee80211_send_probe_req(
454 sdata, NULL,
455 local->scan_req->ssids[i].ssid,
456 local->scan_req->ssids[i].ssid_len,
457 local->scan_req->ie, local->scan_req->ie_len,
458 local->scan_req->rates[band], false,
459 tx_flags, local->hw.conf.chandef.chan, true);
460
461 /*
462 * After sending probe requests, wait for probe responses
463 * on the channel.
464 */
465 *next_delay = IEEE80211_CHANNEL_TIME;
466 local->next_scan_state = SCAN_DECISION;
467 }
468
469 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
470 struct cfg80211_scan_request *req)
471 {
472 struct ieee80211_local *local = sdata->local;
473 int rc;
474
475 lockdep_assert_held(&local->mtx);
476
477 if (local->scan_req)
478 return -EBUSY;
479
480 if (!ieee80211_can_scan(local, sdata)) {
481 /* wait for the work to finish/time out */
482 local->scan_req = req;
483 rcu_assign_pointer(local->scan_sdata, sdata);
484 return 0;
485 }
486
487 if (local->ops->hw_scan) {
488 u8 *ies;
489
490 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
491
492 if (local->hw.flags & IEEE80211_SINGLE_HW_SCAN_ON_ALL_BANDS) {
493 int i, n_bands = 0;
494 u8 bands_counted = 0;
495
496 for (i = 0; i < req->n_channels; i++) {
497 if (bands_counted & BIT(req->channels[i]->band))
498 continue;
499 bands_counted |= BIT(req->channels[i]->band);
500 n_bands++;
501 }
502
503 local->hw_scan_ies_bufsize *= n_bands;
504 }
505
506 local->hw_scan_req = kmalloc(
507 sizeof(*local->hw_scan_req) +
508 req->n_channels * sizeof(req->channels[0]) +
509 local->hw_scan_ies_bufsize, GFP_KERNEL);
510 if (!local->hw_scan_req)
511 return -ENOMEM;
512
513 local->hw_scan_req->req.ssids = req->ssids;
514 local->hw_scan_req->req.n_ssids = req->n_ssids;
515 ies = (u8 *)local->hw_scan_req +
516 sizeof(*local->hw_scan_req) +
517 req->n_channels * sizeof(req->channels[0]);
518 local->hw_scan_req->req.ie = ies;
519 local->hw_scan_req->req.flags = req->flags;
520
521 local->hw_scan_band = 0;
522
523 /*
524 * After allocating local->hw_scan_req, we must
525 * go through until ieee80211_prep_hw_scan(), so
526 * anything that might be changed here and leave
527 * this function early must not go after this
528 * allocation.
529 */
530 }
531
532 local->scan_req = req;
533 rcu_assign_pointer(local->scan_sdata, sdata);
534
535 if (local->ops->hw_scan) {
536 __set_bit(SCAN_HW_SCANNING, &local->scanning);
537 } else if ((req->n_channels == 1) &&
538 (req->channels[0] == local->_oper_chandef.chan)) {
539 /*
540 * If we are scanning only on the operating channel
541 * then we do not need to stop normal activities
542 */
543 unsigned long next_delay;
544
545 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
546
547 ieee80211_recalc_idle(local);
548
549 /* Notify driver scan is starting, keep order of operations
550 * same as normal software scan, in case that matters. */
551 drv_sw_scan_start(local);
552
553 ieee80211_configure_filter(local); /* accept probe-responses */
554
555 /* We need to ensure power level is at max for scanning. */
556 ieee80211_hw_config(local, 0);
557
558 if ((req->channels[0]->flags &
559 IEEE80211_CHAN_NO_IR) ||
560 !local->scan_req->n_ssids) {
561 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
562 } else {
563 ieee80211_scan_state_send_probe(local, &next_delay);
564 next_delay = IEEE80211_CHANNEL_TIME;
565 }
566
567 /* Now, just wait a bit and we are all done! */
568 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
569 next_delay);
570 return 0;
571 } else {
572 /* Do normal software scan */
573 __set_bit(SCAN_SW_SCANNING, &local->scanning);
574 }
575
576 ieee80211_recalc_idle(local);
577
578 if (local->ops->hw_scan) {
579 WARN_ON(!ieee80211_prep_hw_scan(local));
580 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
581 } else
582 rc = ieee80211_start_sw_scan(local);
583
584 if (rc) {
585 kfree(local->hw_scan_req);
586 local->hw_scan_req = NULL;
587 local->scanning = 0;
588
589 ieee80211_recalc_idle(local);
590
591 local->scan_req = NULL;
592 RCU_INIT_POINTER(local->scan_sdata, NULL);
593 }
594
595 return rc;
596 }
597
598 static unsigned long
599 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
600 {
601 /*
602 * TODO: channel switching also consumes quite some time,
603 * add that delay as well to get a better estimation
604 */
605 if (chan->flags & IEEE80211_CHAN_NO_IR)
606 return IEEE80211_PASSIVE_CHANNEL_TIME;
607 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
608 }
609
610 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
611 unsigned long *next_delay)
612 {
613 bool associated = false;
614 bool tx_empty = true;
615 bool bad_latency;
616 struct ieee80211_sub_if_data *sdata;
617 struct ieee80211_channel *next_chan;
618 enum mac80211_scan_state next_scan_state;
619
620 /*
621 * check if at least one STA interface is associated,
622 * check if at least one STA interface has pending tx frames
623 * and grab the lowest used beacon interval
624 */
625 mutex_lock(&local->iflist_mtx);
626 list_for_each_entry(sdata, &local->interfaces, list) {
627 if (!ieee80211_sdata_running(sdata))
628 continue;
629
630 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
631 if (sdata->u.mgd.associated) {
632 associated = true;
633
634 if (!qdisc_all_tx_empty(sdata->dev)) {
635 tx_empty = false;
636 break;
637 }
638 }
639 }
640 }
641 mutex_unlock(&local->iflist_mtx);
642
643 next_chan = local->scan_req->channels[local->scan_channel_idx];
644
645 /*
646 * we're currently scanning a different channel, let's
647 * see if we can scan another channel without interfering
648 * with the current traffic situation.
649 *
650 * Keep good latency, do not stay off-channel more than 125 ms.
651 */
652
653 bad_latency = time_after(jiffies +
654 ieee80211_scan_get_channel_time(next_chan),
655 local->leave_oper_channel_time + HZ / 8);
656
657 if (associated && !tx_empty) {
658 if (local->scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
659 next_scan_state = SCAN_ABORT;
660 else
661 next_scan_state = SCAN_SUSPEND;
662 } else if (associated && bad_latency) {
663 next_scan_state = SCAN_SUSPEND;
664 } else {
665 next_scan_state = SCAN_SET_CHANNEL;
666 }
667
668 local->next_scan_state = next_scan_state;
669
670 *next_delay = 0;
671 }
672
673 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
674 unsigned long *next_delay)
675 {
676 int skip;
677 struct ieee80211_channel *chan;
678 enum nl80211_bss_scan_width oper_scan_width;
679
680 skip = 0;
681 chan = local->scan_req->channels[local->scan_channel_idx];
682
683 local->scan_chandef.chan = chan;
684 local->scan_chandef.center_freq1 = chan->center_freq;
685 local->scan_chandef.center_freq2 = 0;
686 switch (local->scan_req->scan_width) {
687 case NL80211_BSS_CHAN_WIDTH_5:
688 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
689 break;
690 case NL80211_BSS_CHAN_WIDTH_10:
691 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
692 break;
693 case NL80211_BSS_CHAN_WIDTH_20:
694 /* If scanning on oper channel, use whatever channel-type
695 * is currently in use.
696 */
697 oper_scan_width = cfg80211_chandef_to_scan_width(
698 &local->_oper_chandef);
699 if (chan == local->_oper_chandef.chan &&
700 oper_scan_width == local->scan_req->scan_width)
701 local->scan_chandef = local->_oper_chandef;
702 else
703 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
704 break;
705 }
706
707 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
708 skip = 1;
709
710 /* advance state machine to next channel/band */
711 local->scan_channel_idx++;
712
713 if (skip) {
714 /* if we skip this channel return to the decision state */
715 local->next_scan_state = SCAN_DECISION;
716 return;
717 }
718
719 /*
720 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
721 * (which unfortunately doesn't say _why_ step a) is done,
722 * but it waits for the probe delay or until a frame is
723 * received - and the received frame would update the NAV).
724 * For now, we do not support waiting until a frame is
725 * received.
726 *
727 * In any case, it is not necessary for a passive scan.
728 */
729 if (chan->flags & IEEE80211_CHAN_NO_IR ||
730 !local->scan_req->n_ssids) {
731 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
732 local->next_scan_state = SCAN_DECISION;
733 return;
734 }
735
736 /* active scan, send probes */
737 *next_delay = IEEE80211_PROBE_DELAY;
738 local->next_scan_state = SCAN_SEND_PROBE;
739 }
740
741 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
742 unsigned long *next_delay)
743 {
744 /* switch back to the operating channel */
745 local->scan_chandef.chan = NULL;
746 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
747
748 /* disable PS */
749 ieee80211_offchannel_return(local);
750
751 *next_delay = HZ / 5;
752 /* afterwards, resume scan & go to next channel */
753 local->next_scan_state = SCAN_RESUME;
754 }
755
756 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
757 unsigned long *next_delay)
758 {
759 ieee80211_offchannel_stop_vifs(local);
760
761 if (local->ops->flush) {
762 ieee80211_flush_queues(local, NULL);
763 *next_delay = 0;
764 } else
765 *next_delay = HZ / 10;
766
767 /* remember when we left the operating channel */
768 local->leave_oper_channel_time = jiffies;
769
770 /* advance to the next channel to be scanned */
771 local->next_scan_state = SCAN_SET_CHANNEL;
772 }
773
774 void ieee80211_scan_work(struct work_struct *work)
775 {
776 struct ieee80211_local *local =
777 container_of(work, struct ieee80211_local, scan_work.work);
778 struct ieee80211_sub_if_data *sdata;
779 unsigned long next_delay = 0;
780 bool aborted;
781
782 mutex_lock(&local->mtx);
783
784 sdata = rcu_dereference_protected(local->scan_sdata,
785 lockdep_is_held(&local->mtx));
786
787 /* When scanning on-channel, the first-callback means completed. */
788 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
789 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
790 goto out_complete;
791 }
792
793 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
794 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
795 goto out_complete;
796 }
797
798 if (!sdata || !local->scan_req)
799 goto out;
800
801 if (local->scan_req && !local->scanning) {
802 struct cfg80211_scan_request *req = local->scan_req;
803 int rc;
804
805 local->scan_req = NULL;
806 RCU_INIT_POINTER(local->scan_sdata, NULL);
807
808 rc = __ieee80211_start_scan(sdata, req);
809 if (rc) {
810 /* need to complete scan in cfg80211 */
811 local->scan_req = req;
812 aborted = true;
813 goto out_complete;
814 } else
815 goto out;
816 }
817
818 /*
819 * as long as no delay is required advance immediately
820 * without scheduling a new work
821 */
822 do {
823 if (!ieee80211_sdata_running(sdata)) {
824 aborted = true;
825 goto out_complete;
826 }
827
828 switch (local->next_scan_state) {
829 case SCAN_DECISION:
830 /* if no more bands/channels left, complete scan */
831 if (local->scan_channel_idx >= local->scan_req->n_channels) {
832 aborted = false;
833 goto out_complete;
834 }
835 ieee80211_scan_state_decision(local, &next_delay);
836 break;
837 case SCAN_SET_CHANNEL:
838 ieee80211_scan_state_set_channel(local, &next_delay);
839 break;
840 case SCAN_SEND_PROBE:
841 ieee80211_scan_state_send_probe(local, &next_delay);
842 break;
843 case SCAN_SUSPEND:
844 ieee80211_scan_state_suspend(local, &next_delay);
845 break;
846 case SCAN_RESUME:
847 ieee80211_scan_state_resume(local, &next_delay);
848 break;
849 case SCAN_ABORT:
850 aborted = true;
851 goto out_complete;
852 }
853 } while (next_delay == 0);
854
855 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
856 goto out;
857
858 out_complete:
859 __ieee80211_scan_completed(&local->hw, aborted);
860 out:
861 mutex_unlock(&local->mtx);
862 }
863
864 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
865 struct cfg80211_scan_request *req)
866 {
867 int res;
868
869 mutex_lock(&sdata->local->mtx);
870 res = __ieee80211_start_scan(sdata, req);
871 mutex_unlock(&sdata->local->mtx);
872
873 return res;
874 }
875
876 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
877 const u8 *ssid, u8 ssid_len,
878 struct ieee80211_channel *chan,
879 enum nl80211_bss_scan_width scan_width)
880 {
881 struct ieee80211_local *local = sdata->local;
882 int ret = -EBUSY;
883 enum ieee80211_band band;
884
885 mutex_lock(&local->mtx);
886
887 /* busy scanning */
888 if (local->scan_req)
889 goto unlock;
890
891 /* fill internal scan request */
892 if (!chan) {
893 int i, max_n;
894 int n_ch = 0;
895
896 for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
897 if (!local->hw.wiphy->bands[band])
898 continue;
899
900 max_n = local->hw.wiphy->bands[band]->n_channels;
901 for (i = 0; i < max_n; i++) {
902 struct ieee80211_channel *tmp_ch =
903 &local->hw.wiphy->bands[band]->channels[i];
904
905 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
906 IEEE80211_CHAN_DISABLED))
907 continue;
908
909 local->int_scan_req->channels[n_ch] = tmp_ch;
910 n_ch++;
911 }
912 }
913
914 if (WARN_ON_ONCE(n_ch == 0))
915 goto unlock;
916
917 local->int_scan_req->n_channels = n_ch;
918 } else {
919 if (WARN_ON_ONCE(chan->flags & (IEEE80211_CHAN_NO_IR |
920 IEEE80211_CHAN_DISABLED)))
921 goto unlock;
922
923 local->int_scan_req->channels[0] = chan;
924 local->int_scan_req->n_channels = 1;
925 }
926
927 local->int_scan_req->ssids = &local->scan_ssid;
928 local->int_scan_req->n_ssids = 1;
929 local->int_scan_req->scan_width = scan_width;
930 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
931 local->int_scan_req->ssids[0].ssid_len = ssid_len;
932
933 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
934 unlock:
935 mutex_unlock(&local->mtx);
936 return ret;
937 }
938
939 /*
940 * Only call this function when a scan can't be queued -- under RTNL.
941 */
942 void ieee80211_scan_cancel(struct ieee80211_local *local)
943 {
944 /*
945 * We are canceling software scan, or deferred scan that was not
946 * yet really started (see __ieee80211_start_scan ).
947 *
948 * Regarding hardware scan:
949 * - we can not call __ieee80211_scan_completed() as when
950 * SCAN_HW_SCANNING bit is set this function change
951 * local->hw_scan_req to operate on 5G band, what race with
952 * driver which can use local->hw_scan_req
953 *
954 * - we can not cancel scan_work since driver can schedule it
955 * by ieee80211_scan_completed(..., true) to finish scan
956 *
957 * Hence we only call the cancel_hw_scan() callback, but the low-level
958 * driver is still responsible for calling ieee80211_scan_completed()
959 * after the scan was completed/aborted.
960 */
961
962 mutex_lock(&local->mtx);
963 if (!local->scan_req)
964 goto out;
965
966 /*
967 * We have a scan running and the driver already reported completion,
968 * but the worker hasn't run yet or is stuck on the mutex - mark it as
969 * cancelled.
970 */
971 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
972 test_bit(SCAN_COMPLETED, &local->scanning)) {
973 set_bit(SCAN_HW_CANCELLED, &local->scanning);
974 goto out;
975 }
976
977 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
978 /*
979 * Make sure that __ieee80211_scan_completed doesn't trigger a
980 * scan on another band.
981 */
982 set_bit(SCAN_HW_CANCELLED, &local->scanning);
983 if (local->ops->cancel_hw_scan)
984 drv_cancel_hw_scan(local,
985 rcu_dereference_protected(local->scan_sdata,
986 lockdep_is_held(&local->mtx)));
987 goto out;
988 }
989
990 /*
991 * If the work is currently running, it must be blocked on
992 * the mutex, but we'll set scan_sdata = NULL and it'll
993 * simply exit once it acquires the mutex.
994 */
995 cancel_delayed_work(&local->scan_work);
996 /* and clean up */
997 __ieee80211_scan_completed(&local->hw, true);
998 out:
999 mutex_unlock(&local->mtx);
1000 }
1001
1002 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1003 struct cfg80211_sched_scan_request *req)
1004 {
1005 struct ieee80211_local *local = sdata->local;
1006 struct ieee80211_scan_ies sched_scan_ies = {};
1007 struct cfg80211_chan_def chandef;
1008 int ret, i, iebufsz, num_bands = 0;
1009 u32 rate_masks[IEEE80211_NUM_BANDS] = {};
1010 u8 bands_used = 0;
1011 u8 *ie;
1012 size_t len;
1013
1014 iebufsz = local->scan_ies_len + req->ie_len;
1015
1016 lockdep_assert_held(&local->mtx);
1017
1018 if (!local->ops->sched_scan_start)
1019 return -ENOTSUPP;
1020
1021 for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
1022 if (local->hw.wiphy->bands[i]) {
1023 bands_used |= BIT(i);
1024 rate_masks[i] = (u32) -1;
1025 num_bands++;
1026 }
1027 }
1028
1029 ie = kzalloc(num_bands * iebufsz, GFP_KERNEL);
1030 if (!ie) {
1031 ret = -ENOMEM;
1032 goto out;
1033 }
1034
1035 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1036
1037 len = ieee80211_build_preq_ies(local, ie, num_bands * iebufsz,
1038 &sched_scan_ies, req->ie,
1039 req->ie_len, bands_used,
1040 rate_masks, &chandef);
1041
1042 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1043 if (ret == 0) {
1044 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1045 local->sched_scan_req = req;
1046 }
1047
1048 kfree(ie);
1049
1050 out:
1051 if (ret) {
1052 /* Clean in case of failure after HW restart or upon resume. */
1053 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1054 local->sched_scan_req = NULL;
1055 }
1056
1057 return ret;
1058 }
1059
1060 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1061 struct cfg80211_sched_scan_request *req)
1062 {
1063 struct ieee80211_local *local = sdata->local;
1064 int ret;
1065
1066 mutex_lock(&local->mtx);
1067
1068 if (rcu_access_pointer(local->sched_scan_sdata)) {
1069 mutex_unlock(&local->mtx);
1070 return -EBUSY;
1071 }
1072
1073 ret = __ieee80211_request_sched_scan_start(sdata, req);
1074
1075 mutex_unlock(&local->mtx);
1076 return ret;
1077 }
1078
1079 int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata)
1080 {
1081 struct ieee80211_local *local = sdata->local;
1082 int ret = 0;
1083
1084 mutex_lock(&local->mtx);
1085
1086 if (!local->ops->sched_scan_stop) {
1087 ret = -ENOTSUPP;
1088 goto out;
1089 }
1090
1091 /* We don't want to restart sched scan anymore. */
1092 local->sched_scan_req = NULL;
1093
1094 if (rcu_access_pointer(local->sched_scan_sdata)) {
1095 ret = drv_sched_scan_stop(local, sdata);
1096 if (!ret)
1097 rcu_assign_pointer(local->sched_scan_sdata, NULL);
1098 }
1099 out:
1100 mutex_unlock(&local->mtx);
1101
1102 return ret;
1103 }
1104
1105 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1106 {
1107 struct ieee80211_local *local = hw_to_local(hw);
1108
1109 trace_api_sched_scan_results(local);
1110
1111 cfg80211_sched_scan_results(hw->wiphy);
1112 }
1113 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1114
1115 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1116 {
1117 mutex_lock(&local->mtx);
1118
1119 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1120 mutex_unlock(&local->mtx);
1121 return;
1122 }
1123
1124 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1125
1126 /* If sched scan was aborted by the driver. */
1127 local->sched_scan_req = NULL;
1128
1129 mutex_unlock(&local->mtx);
1130
1131 cfg80211_sched_scan_stopped(local->hw.wiphy);
1132 }
1133
1134 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1135 {
1136 struct ieee80211_local *local =
1137 container_of(work, struct ieee80211_local,
1138 sched_scan_stopped_work);
1139
1140 ieee80211_sched_scan_end(local);
1141 }
1142
1143 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1144 {
1145 struct ieee80211_local *local = hw_to_local(hw);
1146
1147 trace_api_sched_scan_stopped(local);
1148
1149 schedule_work(&local->sched_scan_stopped_work);
1150 }
1151 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
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