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mm: synchronize period update interval
[GitHub/LineageOS/android_kernel_motorola_exynos9610.git] / net / mac80211 / scan.c
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 * Copyright 2013-2015 Intel Mobile Communications GmbH
10 * Copyright 2016 Intel Deutschland GmbH
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
15 */
16
17 #include <linux/if_arp.h>
18 #include <linux/etherdevice.h>
19 #include <linux/rtnetlink.h>
20 #include <net/sch_generic.h>
21 #include <linux/slab.h>
22 #include <linux/export.h>
23 #include <net/mac80211.h>
24
25 #include "ieee80211_i.h"
26 #include "driver-ops.h"
27 #include "mesh.h"
28
29 #define IEEE80211_PROBE_DELAY (HZ / 33)
30 #define IEEE80211_CHANNEL_TIME (HZ / 33)
31 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
32
33 void ieee80211_rx_bss_put(struct ieee80211_local *local,
34 struct ieee80211_bss *bss)
35 {
36 if (!bss)
37 return;
38 cfg80211_put_bss(local->hw.wiphy,
39 container_of((void *)bss, struct cfg80211_bss, priv));
40 }
41
42 static bool is_uapsd_supported(struct ieee802_11_elems *elems)
43 {
44 u8 qos_info;
45
46 if (elems->wmm_info && elems->wmm_info_len == 7
47 && elems->wmm_info[5] == 1)
48 qos_info = elems->wmm_info[6];
49 else if (elems->wmm_param && elems->wmm_param_len == 24
50 && elems->wmm_param[5] == 1)
51 qos_info = elems->wmm_param[6];
52 else
53 /* no valid wmm information or parameter element found */
54 return false;
55
56 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
57 }
58
59 struct ieee80211_bss *
60 ieee80211_bss_info_update(struct ieee80211_local *local,
61 struct ieee80211_rx_status *rx_status,
62 struct ieee80211_mgmt *mgmt, size_t len,
63 struct ieee802_11_elems *elems,
64 struct ieee80211_channel *channel)
65 {
66 bool beacon = ieee80211_is_beacon(mgmt->frame_control);
67 struct cfg80211_bss *cbss;
68 struct ieee80211_bss *bss;
69 int clen, srlen;
70 struct cfg80211_inform_bss bss_meta = {
71 .boottime_ns = rx_status->boottime_ns,
72 };
73 bool signal_valid;
74 struct ieee80211_sub_if_data *scan_sdata;
75
76 if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
77 bss_meta.signal = rx_status->signal * 100;
78 else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
79 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
80
81 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
82 if (rx_status->bw == RATE_INFO_BW_5)
83 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
84 else if (rx_status->bw == RATE_INFO_BW_10)
85 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
86
87 bss_meta.chan = channel;
88
89 rcu_read_lock();
90 scan_sdata = rcu_dereference(local->scan_sdata);
91 if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
92 scan_sdata->vif.bss_conf.assoc &&
93 ieee80211_have_rx_timestamp(rx_status)) {
94 bss_meta.parent_tsf =
95 ieee80211_calculate_rx_timestamp(local, rx_status,
96 len + FCS_LEN, 24);
97 ether_addr_copy(bss_meta.parent_bssid,
98 scan_sdata->vif.bss_conf.bssid);
99 }
100 rcu_read_unlock();
101
102 cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
103 mgmt, len, GFP_ATOMIC);
104 if (!cbss)
105 return NULL;
106 /* In case the signal is invalid update the status */
107 signal_valid = abs(channel->center_freq - cbss->channel->center_freq)
108 <= local->hw.wiphy->max_adj_channel_rssi_comp;
109 if (!signal_valid)
110 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
111
112 bss = (void *)cbss->priv;
113
114 if (beacon)
115 bss->device_ts_beacon = rx_status->device_timestamp;
116 else
117 bss->device_ts_presp = rx_status->device_timestamp;
118
119 if (elems->parse_error) {
120 if (beacon)
121 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
122 else
123 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
124 } else {
125 if (beacon)
126 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
127 else
128 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
129 }
130
131 /* save the ERP value so that it is available at association time */
132 if (elems->erp_info && (!elems->parse_error ||
133 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
134 bss->erp_value = elems->erp_info[0];
135 bss->has_erp_value = true;
136 if (!elems->parse_error)
137 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
138 }
139
140 /* replace old supported rates if we get new values */
141 if (!elems->parse_error ||
142 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
143 srlen = 0;
144 if (elems->supp_rates) {
145 clen = IEEE80211_MAX_SUPP_RATES;
146 if (clen > elems->supp_rates_len)
147 clen = elems->supp_rates_len;
148 memcpy(bss->supp_rates, elems->supp_rates, clen);
149 srlen += clen;
150 }
151 if (elems->ext_supp_rates) {
152 clen = IEEE80211_MAX_SUPP_RATES - srlen;
153 if (clen > elems->ext_supp_rates_len)
154 clen = elems->ext_supp_rates_len;
155 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
156 clen);
157 srlen += clen;
158 }
159 if (srlen) {
160 bss->supp_rates_len = srlen;
161 if (!elems->parse_error)
162 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
163 }
164 }
165
166 if (!elems->parse_error ||
167 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
168 bss->wmm_used = elems->wmm_param || elems->wmm_info;
169 bss->uapsd_supported = is_uapsd_supported(elems);
170 if (!elems->parse_error)
171 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
172 }
173
174 if (beacon) {
175 struct ieee80211_supported_band *sband =
176 local->hw.wiphy->bands[rx_status->band];
177 if (!(rx_status->encoding == RX_ENC_HT) &&
178 !(rx_status->encoding == RX_ENC_VHT))
179 bss->beacon_rate =
180 &sband->bitrates[rx_status->rate_idx];
181 }
182
183 return bss;
184 }
185
186 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
187 {
188 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
189 struct ieee80211_sub_if_data *sdata1, *sdata2;
190 struct ieee80211_mgmt *mgmt = (void *)skb->data;
191 struct ieee80211_bss *bss;
192 u8 *elements;
193 struct ieee80211_channel *channel;
194 size_t baselen;
195 struct ieee802_11_elems elems;
196
197 if (skb->len < 24 ||
198 (!ieee80211_is_probe_resp(mgmt->frame_control) &&
199 !ieee80211_is_beacon(mgmt->frame_control)))
200 return;
201
202 sdata1 = rcu_dereference(local->scan_sdata);
203 sdata2 = rcu_dereference(local->sched_scan_sdata);
204
205 if (likely(!sdata1 && !sdata2))
206 return;
207
208 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
209 struct cfg80211_scan_request *scan_req;
210 struct cfg80211_sched_scan_request *sched_scan_req;
211
212 scan_req = rcu_dereference(local->scan_req);
213 sched_scan_req = rcu_dereference(local->sched_scan_req);
214
215 /* ignore ProbeResp to foreign address unless scanning
216 * with randomised address
217 */
218 if (!(sdata1 &&
219 (ether_addr_equal(mgmt->da, sdata1->vif.addr) ||
220 scan_req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)) &&
221 !(sdata2 &&
222 (ether_addr_equal(mgmt->da, sdata2->vif.addr) ||
223 sched_scan_req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)))
224 return;
225
226 elements = mgmt->u.probe_resp.variable;
227 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
228 } else {
229 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
230 elements = mgmt->u.beacon.variable;
231 }
232
233 if (baselen > skb->len)
234 return;
235
236 ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems);
237
238 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
239
240 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
241 return;
242
243 bss = ieee80211_bss_info_update(local, rx_status,
244 mgmt, skb->len, &elems,
245 channel);
246 if (bss)
247 ieee80211_rx_bss_put(local, bss);
248 }
249
250 static void
251 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
252 enum nl80211_bss_scan_width scan_width)
253 {
254 memset(chandef, 0, sizeof(*chandef));
255 switch (scan_width) {
256 case NL80211_BSS_CHAN_WIDTH_5:
257 chandef->width = NL80211_CHAN_WIDTH_5;
258 break;
259 case NL80211_BSS_CHAN_WIDTH_10:
260 chandef->width = NL80211_CHAN_WIDTH_10;
261 break;
262 default:
263 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
264 break;
265 }
266 }
267
268 /* return false if no more work */
269 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
270 {
271 struct cfg80211_scan_request *req;
272 struct cfg80211_chan_def chandef;
273 u8 bands_used = 0;
274 int i, ielen, n_chans;
275
276 req = rcu_dereference_protected(local->scan_req,
277 lockdep_is_held(&local->mtx));
278
279 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
280 return false;
281
282 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
283 for (i = 0; i < req->n_channels; i++) {
284 local->hw_scan_req->req.channels[i] = req->channels[i];
285 bands_used |= BIT(req->channels[i]->band);
286 }
287
288 n_chans = req->n_channels;
289 } else {
290 do {
291 if (local->hw_scan_band == NUM_NL80211_BANDS)
292 return false;
293
294 n_chans = 0;
295
296 for (i = 0; i < req->n_channels; i++) {
297 if (req->channels[i]->band !=
298 local->hw_scan_band)
299 continue;
300 local->hw_scan_req->req.channels[n_chans] =
301 req->channels[i];
302 n_chans++;
303 bands_used |= BIT(req->channels[i]->band);
304 }
305
306 local->hw_scan_band++;
307 } while (!n_chans);
308 }
309
310 local->hw_scan_req->req.n_channels = n_chans;
311 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
312
313 ielen = ieee80211_build_preq_ies(local,
314 (u8 *)local->hw_scan_req->req.ie,
315 local->hw_scan_ies_bufsize,
316 &local->hw_scan_req->ies,
317 req->ie, req->ie_len,
318 bands_used, req->rates, &chandef);
319 local->hw_scan_req->req.ie_len = ielen;
320 local->hw_scan_req->req.no_cck = req->no_cck;
321 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
322 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
323 req->mac_addr_mask);
324 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
325
326 return true;
327 }
328
329 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
330 {
331 struct ieee80211_local *local = hw_to_local(hw);
332 bool hw_scan = local->ops->hw_scan;
333 bool was_scanning = local->scanning;
334 struct cfg80211_scan_request *scan_req;
335 struct ieee80211_sub_if_data *scan_sdata;
336 struct ieee80211_sub_if_data *sdata;
337
338 lockdep_assert_held(&local->mtx);
339
340 /*
341 * It's ok to abort a not-yet-running scan (that
342 * we have one at all will be verified by checking
343 * local->scan_req next), but not to complete it
344 * successfully.
345 */
346 if (WARN_ON(!local->scanning && !aborted))
347 aborted = true;
348
349 if (WARN_ON(!local->scan_req))
350 return;
351
352 if (hw_scan && !aborted &&
353 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
354 ieee80211_prep_hw_scan(local)) {
355 int rc;
356
357 rc = drv_hw_scan(local,
358 rcu_dereference_protected(local->scan_sdata,
359 lockdep_is_held(&local->mtx)),
360 local->hw_scan_req);
361
362 if (rc == 0)
363 return;
364
365 /* HW scan failed and is going to be reported as aborted,
366 * so clear old scan info.
367 */
368 memset(&local->scan_info, 0, sizeof(local->scan_info));
369 aborted = true;
370 }
371
372 kfree(local->hw_scan_req);
373 local->hw_scan_req = NULL;
374
375 scan_req = rcu_dereference_protected(local->scan_req,
376 lockdep_is_held(&local->mtx));
377
378 if (scan_req != local->int_scan_req) {
379 local->scan_info.aborted = aborted;
380 cfg80211_scan_done(scan_req, &local->scan_info);
381 }
382 RCU_INIT_POINTER(local->scan_req, NULL);
383
384 scan_sdata = rcu_dereference_protected(local->scan_sdata,
385 lockdep_is_held(&local->mtx));
386 RCU_INIT_POINTER(local->scan_sdata, NULL);
387
388 local->scanning = 0;
389 local->scan_chandef.chan = NULL;
390
391 /* Set power back to normal operating levels. */
392 ieee80211_hw_config(local, 0);
393
394 if (!hw_scan) {
395 ieee80211_configure_filter(local);
396 drv_sw_scan_complete(local, scan_sdata);
397 ieee80211_offchannel_return(local);
398 }
399
400 ieee80211_recalc_idle(local);
401
402 ieee80211_mlme_notify_scan_completed(local);
403 ieee80211_ibss_notify_scan_completed(local);
404
405 /* Requeue all the work that might have been ignored while
406 * the scan was in progress; if there was none this will
407 * just be a no-op for the particular interface.
408 */
409 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
410 if (ieee80211_sdata_running(sdata))
411 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
412 }
413
414 if (was_scanning)
415 ieee80211_start_next_roc(local);
416 }
417
418 void ieee80211_scan_completed(struct ieee80211_hw *hw,
419 struct cfg80211_scan_info *info)
420 {
421 struct ieee80211_local *local = hw_to_local(hw);
422
423 trace_api_scan_completed(local, info->aborted);
424
425 set_bit(SCAN_COMPLETED, &local->scanning);
426 if (info->aborted)
427 set_bit(SCAN_ABORTED, &local->scanning);
428
429 memcpy(&local->scan_info, info, sizeof(*info));
430
431 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
432 }
433 EXPORT_SYMBOL(ieee80211_scan_completed);
434
435 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
436 struct ieee80211_sub_if_data *sdata)
437 {
438 /* Software scan is not supported in multi-channel cases */
439 if (local->use_chanctx)
440 return -EOPNOTSUPP;
441
442 /*
443 * Hardware/driver doesn't support hw_scan, so use software
444 * scanning instead. First send a nullfunc frame with power save
445 * bit on so that AP will buffer the frames for us while we are not
446 * listening, then send probe requests to each channel and wait for
447 * the responses. After all channels are scanned, tune back to the
448 * original channel and send a nullfunc frame with power save bit
449 * off to trigger the AP to send us all the buffered frames.
450 *
451 * Note that while local->sw_scanning is true everything else but
452 * nullfunc frames and probe requests will be dropped in
453 * ieee80211_tx_h_check_assoc().
454 */
455 drv_sw_scan_start(local, sdata, local->scan_addr);
456
457 local->leave_oper_channel_time = jiffies;
458 local->next_scan_state = SCAN_DECISION;
459 local->scan_channel_idx = 0;
460
461 ieee80211_offchannel_stop_vifs(local);
462
463 /* ensure nullfunc is transmitted before leaving operating channel */
464 ieee80211_flush_queues(local, NULL, false);
465
466 ieee80211_configure_filter(local);
467
468 /* We need to set power level at maximum rate for scanning. */
469 ieee80211_hw_config(local, 0);
470
471 ieee80211_queue_delayed_work(&local->hw,
472 &local->scan_work, 0);
473
474 return 0;
475 }
476
477 static bool ieee80211_can_scan(struct ieee80211_local *local,
478 struct ieee80211_sub_if_data *sdata)
479 {
480 if (ieee80211_is_radar_required(local))
481 return false;
482
483 if (!list_empty(&local->roc_list))
484 return false;
485
486 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
487 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
488 return false;
489
490 return true;
491 }
492
493 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
494 {
495 lockdep_assert_held(&local->mtx);
496
497 if (!local->scan_req || local->scanning)
498 return;
499
500 if (!ieee80211_can_scan(local,
501 rcu_dereference_protected(
502 local->scan_sdata,
503 lockdep_is_held(&local->mtx))))
504 return;
505
506 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
507 round_jiffies_relative(0));
508 }
509
510 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
511 unsigned long *next_delay)
512 {
513 int i;
514 struct ieee80211_sub_if_data *sdata;
515 struct cfg80211_scan_request *scan_req;
516 enum nl80211_band band = local->hw.conf.chandef.chan->band;
517 u32 tx_flags;
518
519 scan_req = rcu_dereference_protected(local->scan_req,
520 lockdep_is_held(&local->mtx));
521
522 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
523 if (scan_req->no_cck)
524 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
525
526 sdata = rcu_dereference_protected(local->scan_sdata,
527 lockdep_is_held(&local->mtx));
528
529 for (i = 0; i < scan_req->n_ssids; i++)
530 ieee80211_send_probe_req(
531 sdata, local->scan_addr, scan_req->bssid,
532 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
533 scan_req->ie, scan_req->ie_len,
534 scan_req->rates[band], false,
535 tx_flags, local->hw.conf.chandef.chan, true);
536
537 /*
538 * After sending probe requests, wait for probe responses
539 * on the channel.
540 */
541 *next_delay = IEEE80211_CHANNEL_TIME;
542 local->next_scan_state = SCAN_DECISION;
543 }
544
545 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
546 struct cfg80211_scan_request *req)
547 {
548 struct ieee80211_local *local = sdata->local;
549 int rc;
550
551 lockdep_assert_held(&local->mtx);
552
553 if (local->scan_req || ieee80211_is_radar_required(local))
554 return -EBUSY;
555
556 if (!ieee80211_can_scan(local, sdata)) {
557 /* wait for the work to finish/time out */
558 rcu_assign_pointer(local->scan_req, req);
559 rcu_assign_pointer(local->scan_sdata, sdata);
560 return 0;
561 }
562
563 if (local->ops->hw_scan) {
564 u8 *ies;
565
566 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
567
568 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
569 int i, n_bands = 0;
570 u8 bands_counted = 0;
571
572 for (i = 0; i < req->n_channels; i++) {
573 if (bands_counted & BIT(req->channels[i]->band))
574 continue;
575 bands_counted |= BIT(req->channels[i]->band);
576 n_bands++;
577 }
578
579 local->hw_scan_ies_bufsize *= n_bands;
580 }
581
582 local->hw_scan_req = kmalloc(
583 sizeof(*local->hw_scan_req) +
584 req->n_channels * sizeof(req->channels[0]) +
585 local->hw_scan_ies_bufsize, GFP_KERNEL);
586 if (!local->hw_scan_req)
587 return -ENOMEM;
588
589 local->hw_scan_req->req.ssids = req->ssids;
590 local->hw_scan_req->req.n_ssids = req->n_ssids;
591 ies = (u8 *)local->hw_scan_req +
592 sizeof(*local->hw_scan_req) +
593 req->n_channels * sizeof(req->channels[0]);
594 local->hw_scan_req->req.ie = ies;
595 local->hw_scan_req->req.flags = req->flags;
596 eth_broadcast_addr(local->hw_scan_req->req.bssid);
597 local->hw_scan_req->req.duration = req->duration;
598 local->hw_scan_req->req.duration_mandatory =
599 req->duration_mandatory;
600
601 local->hw_scan_band = 0;
602
603 /*
604 * After allocating local->hw_scan_req, we must
605 * go through until ieee80211_prep_hw_scan(), so
606 * anything that might be changed here and leave
607 * this function early must not go after this
608 * allocation.
609 */
610 }
611
612 rcu_assign_pointer(local->scan_req, req);
613 rcu_assign_pointer(local->scan_sdata, sdata);
614
615 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
616 get_random_mask_addr(local->scan_addr,
617 req->mac_addr,
618 req->mac_addr_mask);
619 else
620 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
621
622 if (local->ops->hw_scan) {
623 __set_bit(SCAN_HW_SCANNING, &local->scanning);
624 } else if ((req->n_channels == 1) &&
625 (req->channels[0] == local->_oper_chandef.chan)) {
626 /*
627 * If we are scanning only on the operating channel
628 * then we do not need to stop normal activities
629 */
630 unsigned long next_delay;
631
632 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
633
634 ieee80211_recalc_idle(local);
635
636 /* Notify driver scan is starting, keep order of operations
637 * same as normal software scan, in case that matters. */
638 drv_sw_scan_start(local, sdata, local->scan_addr);
639
640 ieee80211_configure_filter(local); /* accept probe-responses */
641
642 /* We need to ensure power level is at max for scanning. */
643 ieee80211_hw_config(local, 0);
644
645 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
646 IEEE80211_CHAN_RADAR)) ||
647 !req->n_ssids) {
648 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
649 } else {
650 ieee80211_scan_state_send_probe(local, &next_delay);
651 next_delay = IEEE80211_CHANNEL_TIME;
652 }
653
654 /* Now, just wait a bit and we are all done! */
655 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
656 next_delay);
657 return 0;
658 } else {
659 /* Do normal software scan */
660 __set_bit(SCAN_SW_SCANNING, &local->scanning);
661 }
662
663 ieee80211_recalc_idle(local);
664
665 if (local->ops->hw_scan) {
666 WARN_ON(!ieee80211_prep_hw_scan(local));
667 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
668 } else {
669 rc = ieee80211_start_sw_scan(local, sdata);
670 }
671
672 if (rc) {
673 kfree(local->hw_scan_req);
674 local->hw_scan_req = NULL;
675 local->scanning = 0;
676
677 ieee80211_recalc_idle(local);
678
679 local->scan_req = NULL;
680 RCU_INIT_POINTER(local->scan_sdata, NULL);
681 }
682
683 return rc;
684 }
685
686 static unsigned long
687 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
688 {
689 /*
690 * TODO: channel switching also consumes quite some time,
691 * add that delay as well to get a better estimation
692 */
693 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
694 return IEEE80211_PASSIVE_CHANNEL_TIME;
695 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
696 }
697
698 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
699 unsigned long *next_delay)
700 {
701 bool associated = false;
702 bool tx_empty = true;
703 bool bad_latency;
704 struct ieee80211_sub_if_data *sdata;
705 struct ieee80211_channel *next_chan;
706 enum mac80211_scan_state next_scan_state;
707 struct cfg80211_scan_request *scan_req;
708
709 /*
710 * check if at least one STA interface is associated,
711 * check if at least one STA interface has pending tx frames
712 * and grab the lowest used beacon interval
713 */
714 mutex_lock(&local->iflist_mtx);
715 list_for_each_entry(sdata, &local->interfaces, list) {
716 if (!ieee80211_sdata_running(sdata))
717 continue;
718
719 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
720 if (sdata->u.mgd.associated) {
721 associated = true;
722
723 if (!qdisc_all_tx_empty(sdata->dev)) {
724 tx_empty = false;
725 break;
726 }
727 }
728 }
729 }
730 mutex_unlock(&local->iflist_mtx);
731
732 scan_req = rcu_dereference_protected(local->scan_req,
733 lockdep_is_held(&local->mtx));
734
735 next_chan = scan_req->channels[local->scan_channel_idx];
736
737 /*
738 * we're currently scanning a different channel, let's
739 * see if we can scan another channel without interfering
740 * with the current traffic situation.
741 *
742 * Keep good latency, do not stay off-channel more than 125 ms.
743 */
744
745 bad_latency = time_after(jiffies +
746 ieee80211_scan_get_channel_time(next_chan),
747 local->leave_oper_channel_time + HZ / 8);
748
749 if (associated && !tx_empty) {
750 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
751 next_scan_state = SCAN_ABORT;
752 else
753 next_scan_state = SCAN_SUSPEND;
754 } else if (associated && bad_latency) {
755 next_scan_state = SCAN_SUSPEND;
756 } else {
757 next_scan_state = SCAN_SET_CHANNEL;
758 }
759
760 local->next_scan_state = next_scan_state;
761
762 *next_delay = 0;
763 }
764
765 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
766 unsigned long *next_delay)
767 {
768 int skip;
769 struct ieee80211_channel *chan;
770 enum nl80211_bss_scan_width oper_scan_width;
771 struct cfg80211_scan_request *scan_req;
772
773 scan_req = rcu_dereference_protected(local->scan_req,
774 lockdep_is_held(&local->mtx));
775
776 skip = 0;
777 chan = scan_req->channels[local->scan_channel_idx];
778
779 local->scan_chandef.chan = chan;
780 local->scan_chandef.center_freq1 = chan->center_freq;
781 local->scan_chandef.center_freq2 = 0;
782 switch (scan_req->scan_width) {
783 case NL80211_BSS_CHAN_WIDTH_5:
784 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
785 break;
786 case NL80211_BSS_CHAN_WIDTH_10:
787 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
788 break;
789 case NL80211_BSS_CHAN_WIDTH_20:
790 /* If scanning on oper channel, use whatever channel-type
791 * is currently in use.
792 */
793 oper_scan_width = cfg80211_chandef_to_scan_width(
794 &local->_oper_chandef);
795 if (chan == local->_oper_chandef.chan &&
796 oper_scan_width == scan_req->scan_width)
797 local->scan_chandef = local->_oper_chandef;
798 else
799 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
800 break;
801 }
802
803 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
804 skip = 1;
805
806 /* advance state machine to next channel/band */
807 local->scan_channel_idx++;
808
809 if (skip) {
810 /* if we skip this channel return to the decision state */
811 local->next_scan_state = SCAN_DECISION;
812 return;
813 }
814
815 /*
816 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
817 * (which unfortunately doesn't say _why_ step a) is done,
818 * but it waits for the probe delay or until a frame is
819 * received - and the received frame would update the NAV).
820 * For now, we do not support waiting until a frame is
821 * received.
822 *
823 * In any case, it is not necessary for a passive scan.
824 */
825 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
826 !scan_req->n_ssids) {
827 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
828 local->next_scan_state = SCAN_DECISION;
829 return;
830 }
831
832 /* active scan, send probes */
833 *next_delay = IEEE80211_PROBE_DELAY;
834 local->next_scan_state = SCAN_SEND_PROBE;
835 }
836
837 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
838 unsigned long *next_delay)
839 {
840 /* switch back to the operating channel */
841 local->scan_chandef.chan = NULL;
842 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
843
844 /* disable PS */
845 ieee80211_offchannel_return(local);
846
847 *next_delay = HZ / 5;
848 /* afterwards, resume scan & go to next channel */
849 local->next_scan_state = SCAN_RESUME;
850 }
851
852 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
853 unsigned long *next_delay)
854 {
855 ieee80211_offchannel_stop_vifs(local);
856
857 if (local->ops->flush) {
858 ieee80211_flush_queues(local, NULL, false);
859 *next_delay = 0;
860 } else
861 *next_delay = HZ / 10;
862
863 /* remember when we left the operating channel */
864 local->leave_oper_channel_time = jiffies;
865
866 /* advance to the next channel to be scanned */
867 local->next_scan_state = SCAN_SET_CHANNEL;
868 }
869
870 void ieee80211_scan_work(struct work_struct *work)
871 {
872 struct ieee80211_local *local =
873 container_of(work, struct ieee80211_local, scan_work.work);
874 struct ieee80211_sub_if_data *sdata;
875 struct cfg80211_scan_request *scan_req;
876 unsigned long next_delay = 0;
877 bool aborted;
878
879 mutex_lock(&local->mtx);
880
881 if (!ieee80211_can_run_worker(local)) {
882 aborted = true;
883 goto out_complete;
884 }
885
886 sdata = rcu_dereference_protected(local->scan_sdata,
887 lockdep_is_held(&local->mtx));
888 scan_req = rcu_dereference_protected(local->scan_req,
889 lockdep_is_held(&local->mtx));
890
891 /* When scanning on-channel, the first-callback means completed. */
892 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
893 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
894 goto out_complete;
895 }
896
897 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
898 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
899 goto out_complete;
900 }
901
902 if (!sdata || !scan_req)
903 goto out;
904
905 if (!local->scanning) {
906 int rc;
907
908 RCU_INIT_POINTER(local->scan_req, NULL);
909 RCU_INIT_POINTER(local->scan_sdata, NULL);
910
911 rc = __ieee80211_start_scan(sdata, scan_req);
912 if (rc) {
913 /* need to complete scan in cfg80211 */
914 rcu_assign_pointer(local->scan_req, scan_req);
915 aborted = true;
916 goto out_complete;
917 } else
918 goto out;
919 }
920
921 /*
922 * as long as no delay is required advance immediately
923 * without scheduling a new work
924 */
925 do {
926 if (!ieee80211_sdata_running(sdata)) {
927 aborted = true;
928 goto out_complete;
929 }
930
931 switch (local->next_scan_state) {
932 case SCAN_DECISION:
933 /* if no more bands/channels left, complete scan */
934 if (local->scan_channel_idx >= scan_req->n_channels) {
935 aborted = false;
936 goto out_complete;
937 }
938 ieee80211_scan_state_decision(local, &next_delay);
939 break;
940 case SCAN_SET_CHANNEL:
941 ieee80211_scan_state_set_channel(local, &next_delay);
942 break;
943 case SCAN_SEND_PROBE:
944 ieee80211_scan_state_send_probe(local, &next_delay);
945 break;
946 case SCAN_SUSPEND:
947 ieee80211_scan_state_suspend(local, &next_delay);
948 break;
949 case SCAN_RESUME:
950 ieee80211_scan_state_resume(local, &next_delay);
951 break;
952 case SCAN_ABORT:
953 aborted = true;
954 goto out_complete;
955 }
956 } while (next_delay == 0);
957
958 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
959 goto out;
960
961 out_complete:
962 __ieee80211_scan_completed(&local->hw, aborted);
963 out:
964 mutex_unlock(&local->mtx);
965 }
966
967 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
968 struct cfg80211_scan_request *req)
969 {
970 int res;
971
972 mutex_lock(&sdata->local->mtx);
973 res = __ieee80211_start_scan(sdata, req);
974 mutex_unlock(&sdata->local->mtx);
975
976 return res;
977 }
978
979 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
980 const u8 *ssid, u8 ssid_len,
981 struct ieee80211_channel **channels,
982 unsigned int n_channels,
983 enum nl80211_bss_scan_width scan_width)
984 {
985 struct ieee80211_local *local = sdata->local;
986 int ret = -EBUSY, i, n_ch = 0;
987 enum nl80211_band band;
988
989 mutex_lock(&local->mtx);
990
991 /* busy scanning */
992 if (local->scan_req)
993 goto unlock;
994
995 /* fill internal scan request */
996 if (!channels) {
997 int max_n;
998
999 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1000 if (!local->hw.wiphy->bands[band])
1001 continue;
1002
1003 max_n = local->hw.wiphy->bands[band]->n_channels;
1004 for (i = 0; i < max_n; i++) {
1005 struct ieee80211_channel *tmp_ch =
1006 &local->hw.wiphy->bands[band]->channels[i];
1007
1008 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1009 IEEE80211_CHAN_DISABLED))
1010 continue;
1011
1012 local->int_scan_req->channels[n_ch] = tmp_ch;
1013 n_ch++;
1014 }
1015 }
1016
1017 if (WARN_ON_ONCE(n_ch == 0))
1018 goto unlock;
1019
1020 local->int_scan_req->n_channels = n_ch;
1021 } else {
1022 for (i = 0; i < n_channels; i++) {
1023 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1024 IEEE80211_CHAN_DISABLED))
1025 continue;
1026
1027 local->int_scan_req->channels[n_ch] = channels[i];
1028 n_ch++;
1029 }
1030
1031 if (WARN_ON_ONCE(n_ch == 0))
1032 goto unlock;
1033
1034 local->int_scan_req->n_channels = n_ch;
1035 }
1036
1037 local->int_scan_req->ssids = &local->scan_ssid;
1038 local->int_scan_req->n_ssids = 1;
1039 local->int_scan_req->scan_width = scan_width;
1040 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1041 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1042
1043 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1044 unlock:
1045 mutex_unlock(&local->mtx);
1046 return ret;
1047 }
1048
1049 /*
1050 * Only call this function when a scan can't be queued -- under RTNL.
1051 */
1052 void ieee80211_scan_cancel(struct ieee80211_local *local)
1053 {
1054 /*
1055 * We are canceling software scan, or deferred scan that was not
1056 * yet really started (see __ieee80211_start_scan ).
1057 *
1058 * Regarding hardware scan:
1059 * - we can not call __ieee80211_scan_completed() as when
1060 * SCAN_HW_SCANNING bit is set this function change
1061 * local->hw_scan_req to operate on 5G band, what race with
1062 * driver which can use local->hw_scan_req
1063 *
1064 * - we can not cancel scan_work since driver can schedule it
1065 * by ieee80211_scan_completed(..., true) to finish scan
1066 *
1067 * Hence we only call the cancel_hw_scan() callback, but the low-level
1068 * driver is still responsible for calling ieee80211_scan_completed()
1069 * after the scan was completed/aborted.
1070 */
1071
1072 mutex_lock(&local->mtx);
1073 if (!local->scan_req)
1074 goto out;
1075
1076 /*
1077 * We have a scan running and the driver already reported completion,
1078 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1079 * cancelled.
1080 */
1081 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1082 test_bit(SCAN_COMPLETED, &local->scanning)) {
1083 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1084 goto out;
1085 }
1086
1087 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1088 /*
1089 * Make sure that __ieee80211_scan_completed doesn't trigger a
1090 * scan on another band.
1091 */
1092 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1093 if (local->ops->cancel_hw_scan)
1094 drv_cancel_hw_scan(local,
1095 rcu_dereference_protected(local->scan_sdata,
1096 lockdep_is_held(&local->mtx)));
1097 goto out;
1098 }
1099
1100 /*
1101 * If the work is currently running, it must be blocked on
1102 * the mutex, but we'll set scan_sdata = NULL and it'll
1103 * simply exit once it acquires the mutex.
1104 */
1105 cancel_delayed_work(&local->scan_work);
1106 /* and clean up */
1107 memset(&local->scan_info, 0, sizeof(local->scan_info));
1108 __ieee80211_scan_completed(&local->hw, true);
1109 out:
1110 mutex_unlock(&local->mtx);
1111 }
1112
1113 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1114 struct cfg80211_sched_scan_request *req)
1115 {
1116 struct ieee80211_local *local = sdata->local;
1117 struct ieee80211_scan_ies sched_scan_ies = {};
1118 struct cfg80211_chan_def chandef;
1119 int ret, i, iebufsz, num_bands = 0;
1120 u32 rate_masks[NUM_NL80211_BANDS] = {};
1121 u8 bands_used = 0;
1122 u8 *ie;
1123
1124 iebufsz = local->scan_ies_len + req->ie_len;
1125
1126 lockdep_assert_held(&local->mtx);
1127
1128 if (!local->ops->sched_scan_start)
1129 return -ENOTSUPP;
1130
1131 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1132 if (local->hw.wiphy->bands[i]) {
1133 bands_used |= BIT(i);
1134 rate_masks[i] = (u32) -1;
1135 num_bands++;
1136 }
1137 }
1138
1139 ie = kzalloc(num_bands * iebufsz, GFP_KERNEL);
1140 if (!ie) {
1141 ret = -ENOMEM;
1142 goto out;
1143 }
1144
1145 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1146
1147 ieee80211_build_preq_ies(local, ie, num_bands * iebufsz,
1148 &sched_scan_ies, req->ie,
1149 req->ie_len, bands_used, rate_masks, &chandef);
1150
1151 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1152 if (ret == 0) {
1153 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1154 rcu_assign_pointer(local->sched_scan_req, req);
1155 }
1156
1157 kfree(ie);
1158
1159 out:
1160 if (ret) {
1161 /* Clean in case of failure after HW restart or upon resume. */
1162 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1163 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1164 }
1165
1166 return ret;
1167 }
1168
1169 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1170 struct cfg80211_sched_scan_request *req)
1171 {
1172 struct ieee80211_local *local = sdata->local;
1173 int ret;
1174
1175 mutex_lock(&local->mtx);
1176
1177 if (rcu_access_pointer(local->sched_scan_sdata)) {
1178 mutex_unlock(&local->mtx);
1179 return -EBUSY;
1180 }
1181
1182 ret = __ieee80211_request_sched_scan_start(sdata, req);
1183
1184 mutex_unlock(&local->mtx);
1185 return ret;
1186 }
1187
1188 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1189 {
1190 struct ieee80211_sub_if_data *sched_scan_sdata;
1191 int ret = -ENOENT;
1192
1193 mutex_lock(&local->mtx);
1194
1195 if (!local->ops->sched_scan_stop) {
1196 ret = -ENOTSUPP;
1197 goto out;
1198 }
1199
1200 /* We don't want to restart sched scan anymore. */
1201 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1202
1203 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1204 lockdep_is_held(&local->mtx));
1205 if (sched_scan_sdata) {
1206 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1207 if (!ret)
1208 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1209 }
1210 out:
1211 mutex_unlock(&local->mtx);
1212
1213 return ret;
1214 }
1215
1216 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1217 {
1218 struct ieee80211_local *local = hw_to_local(hw);
1219
1220 trace_api_sched_scan_results(local);
1221
1222 cfg80211_sched_scan_results(hw->wiphy, 0);
1223 }
1224 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1225
1226 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1227 {
1228 mutex_lock(&local->mtx);
1229
1230 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1231 mutex_unlock(&local->mtx);
1232 return;
1233 }
1234
1235 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1236
1237 /* If sched scan was aborted by the driver. */
1238 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1239
1240 mutex_unlock(&local->mtx);
1241
1242 cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1243 }
1244
1245 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1246 {
1247 struct ieee80211_local *local =
1248 container_of(work, struct ieee80211_local,
1249 sched_scan_stopped_work);
1250
1251 ieee80211_sched_scan_end(local);
1252 }
1253
1254 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1255 {
1256 struct ieee80211_local *local = hw_to_local(hw);
1257
1258 trace_api_sched_scan_stopped(local);
1259
1260 /*
1261 * this shouldn't really happen, so for simplicity
1262 * simply ignore it, and let mac80211 reconfigure
1263 * the sched scan later on.
1264 */
1265 if (local->in_reconfig)
1266 return;
1267
1268 schedule_work(&local->sched_scan_stopped_work);
1269 }
1270 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);