1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Scanning implementation
4 *
5 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
6 * Copyright 2004, Instant802 Networks, Inc.
7 * Copyright 2005, Devicescape Software, Inc.
8 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
9 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
10 * Copyright 2013-2015 Intel Mobile Communications GmbH
11 * Copyright 2016-2017 Intel Deutschland GmbH
12 * Copyright (C) 2018-2024 Intel Corporation
13 */
14
15 #include <linux/if_arp.h>
16 #include <linux/etherdevice.h>
17 #include <linux/rtnetlink.h>
18 #include <net/sch_generic.h>
19 #include <linux/slab.h>
20 #include <linux/export.h>
21 #include <linux/random.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
ieee80211_rx_bss_put(struct ieee80211_local * local,struct ieee80211_bss * bss)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
is_uapsd_supported(struct ieee802_11_elems * elems)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 inform_bss_update_data {
59 struct ieee80211_rx_status *rx_status;
60 bool beacon;
61 };
62
ieee80211_inform_bss(struct wiphy * wiphy,struct cfg80211_bss * cbss,const struct cfg80211_bss_ies * ies,void * data)63 void ieee80211_inform_bss(struct wiphy *wiphy,
64 struct cfg80211_bss *cbss,
65 const struct cfg80211_bss_ies *ies,
66 void *data)
67 {
68 struct ieee80211_local *local = wiphy_priv(wiphy);
69 struct inform_bss_update_data *update_data = data;
70 struct ieee80211_bss *bss = (void *)cbss->priv;
71 struct ieee80211_rx_status *rx_status;
72 struct ieee802_11_elems *elems;
73 int clen, srlen;
74
75 /* This happens while joining an IBSS */
76 if (!update_data)
77 return;
78
79 elems = ieee802_11_parse_elems(ies->data, ies->len, false, NULL);
80 if (!elems)
81 return;
82
83 rx_status = update_data->rx_status;
84
85 if (update_data->beacon)
86 bss->device_ts_beacon = rx_status->device_timestamp;
87 else
88 bss->device_ts_presp = rx_status->device_timestamp;
89
90 if (elems->parse_error) {
91 if (update_data->beacon)
92 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
93 else
94 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
95 } else {
96 if (update_data->beacon)
97 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
98 else
99 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
100 }
101
102 /* save the ERP value so that it is available at association time */
103 if (elems->erp_info && (!elems->parse_error ||
104 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
105 bss->erp_value = elems->erp_info[0];
106 bss->has_erp_value = true;
107 if (!elems->parse_error)
108 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
109 }
110
111 /* replace old supported rates if we get new values */
112 if (!elems->parse_error ||
113 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
114 srlen = 0;
115 if (elems->supp_rates) {
116 clen = IEEE80211_MAX_SUPP_RATES;
117 if (clen > elems->supp_rates_len)
118 clen = elems->supp_rates_len;
119 memcpy(bss->supp_rates, elems->supp_rates, clen);
120 srlen += clen;
121 }
122 if (elems->ext_supp_rates) {
123 clen = IEEE80211_MAX_SUPP_RATES - srlen;
124 if (clen > elems->ext_supp_rates_len)
125 clen = elems->ext_supp_rates_len;
126 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
127 clen);
128 srlen += clen;
129 }
130 if (srlen) {
131 bss->supp_rates_len = srlen;
132 if (!elems->parse_error)
133 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
134 }
135 }
136
137 if (!elems->parse_error ||
138 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
139 bss->wmm_used = elems->wmm_param || elems->wmm_info;
140 bss->uapsd_supported = is_uapsd_supported(elems);
141 if (!elems->parse_error)
142 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
143 }
144
145 if (update_data->beacon) {
146 struct ieee80211_supported_band *sband =
147 local->hw.wiphy->bands[rx_status->band];
148 if (!(rx_status->encoding == RX_ENC_HT) &&
149 !(rx_status->encoding == RX_ENC_VHT))
150 bss->beacon_rate =
151 &sband->bitrates[rx_status->rate_idx];
152 }
153
154 if (elems->vht_cap_elem)
155 bss->vht_cap_info =
156 le32_to_cpu(elems->vht_cap_elem->vht_cap_info);
157 else
158 bss->vht_cap_info = 0;
159
160 kfree(elems);
161 }
162
163 struct ieee80211_bss *
ieee80211_bss_info_update(struct ieee80211_local * local,struct ieee80211_rx_status * rx_status,struct ieee80211_mgmt * mgmt,size_t len,struct ieee80211_channel * channel)164 ieee80211_bss_info_update(struct ieee80211_local *local,
165 struct ieee80211_rx_status *rx_status,
166 struct ieee80211_mgmt *mgmt, size_t len,
167 struct ieee80211_channel *channel)
168 {
169 bool beacon = ieee80211_is_beacon(mgmt->frame_control) ||
170 ieee80211_is_s1g_beacon(mgmt->frame_control);
171 struct cfg80211_bss *cbss;
172 struct inform_bss_update_data update_data = {
173 .rx_status = rx_status,
174 .beacon = beacon,
175 };
176 struct cfg80211_inform_bss bss_meta = {
177 .boottime_ns = rx_status->boottime_ns,
178 .drv_data = (void *)&update_data,
179 };
180 bool signal_valid;
181 struct ieee80211_sub_if_data *scan_sdata;
182
183 if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
184 bss_meta.signal = 0; /* invalid signal indication */
185 else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
186 bss_meta.signal = rx_status->signal * 100;
187 else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
188 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
189
190 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
191 if (rx_status->bw == RATE_INFO_BW_5)
192 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
193 else if (rx_status->bw == RATE_INFO_BW_10)
194 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
195
196 bss_meta.chan = channel;
197
198 rcu_read_lock();
199 scan_sdata = rcu_dereference(local->scan_sdata);
200 if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
201 scan_sdata->vif.cfg.assoc &&
202 ieee80211_have_rx_timestamp(rx_status)) {
203 bss_meta.parent_tsf =
204 ieee80211_calculate_rx_timestamp(local, rx_status,
205 len + FCS_LEN, 24);
206 ether_addr_copy(bss_meta.parent_bssid,
207 scan_sdata->vif.bss_conf.bssid);
208 }
209 rcu_read_unlock();
210
211 cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
212 mgmt, len, GFP_ATOMIC);
213 if (!cbss)
214 return NULL;
215
216 /* In case the signal is invalid update the status */
217 signal_valid = channel == cbss->channel;
218 if (!signal_valid)
219 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
220
221 return (void *)cbss->priv;
222 }
223
ieee80211_scan_accept_presp(struct ieee80211_sub_if_data * sdata,struct ieee80211_channel * channel,u32 scan_flags,const u8 * da)224 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
225 struct ieee80211_channel *channel,
226 u32 scan_flags, const u8 *da)
227 {
228 if (!sdata)
229 return false;
230
231 /* accept broadcast on 6 GHz and for OCE */
232 if (is_broadcast_ether_addr(da) &&
233 (channel->band == NL80211_BAND_6GHZ ||
234 scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP))
235 return true;
236
237 if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
238 return true;
239 return ether_addr_equal(da, sdata->vif.addr);
240 }
241
ieee80211_scan_rx(struct ieee80211_local * local,struct sk_buff * skb)242 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
243 {
244 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
245 struct ieee80211_sub_if_data *sdata1, *sdata2;
246 struct ieee80211_mgmt *mgmt = (void *)skb->data;
247 struct ieee80211_bss *bss;
248 struct ieee80211_channel *channel;
249 size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
250 u.probe_resp.variable);
251
252 if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
253 !ieee80211_is_beacon(mgmt->frame_control) &&
254 !ieee80211_is_s1g_beacon(mgmt->frame_control))
255 return;
256
257 if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
258 if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
259 min_hdr_len = offsetof(struct ieee80211_ext,
260 u.s1g_short_beacon.variable);
261 else
262 min_hdr_len = offsetof(struct ieee80211_ext,
263 u.s1g_beacon);
264 }
265
266 if (skb->len < min_hdr_len)
267 return;
268
269 sdata1 = rcu_dereference(local->scan_sdata);
270 sdata2 = rcu_dereference(local->sched_scan_sdata);
271
272 if (likely(!sdata1 && !sdata2))
273 return;
274
275 if (test_and_clear_bit(SCAN_BEACON_WAIT, &local->scanning)) {
276 /*
277 * we were passive scanning because of radar/no-IR, but
278 * the beacon/proberesp rx gives us an opportunity to upgrade
279 * to active scan
280 */
281 set_bit(SCAN_BEACON_DONE, &local->scanning);
282 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
283 }
284
285 channel = ieee80211_get_channel_khz(local->hw.wiphy,
286 ieee80211_rx_status_to_khz(rx_status));
287
288 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
289 return;
290
291 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
292 struct cfg80211_scan_request *scan_req;
293 struct cfg80211_sched_scan_request *sched_scan_req;
294 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
295
296 scan_req = rcu_dereference(local->scan_req);
297 sched_scan_req = rcu_dereference(local->sched_scan_req);
298
299 if (scan_req)
300 scan_req_flags = scan_req->flags;
301
302 if (sched_scan_req)
303 sched_scan_req_flags = sched_scan_req->flags;
304
305 /* ignore ProbeResp to foreign address or non-bcast (OCE)
306 * unless scanning with randomised address
307 */
308 if (!ieee80211_scan_accept_presp(sdata1, channel,
309 scan_req_flags,
310 mgmt->da) &&
311 !ieee80211_scan_accept_presp(sdata2, channel,
312 sched_scan_req_flags,
313 mgmt->da))
314 return;
315 }
316
317 bss = ieee80211_bss_info_update(local, rx_status,
318 mgmt, skb->len,
319 channel);
320 if (bss)
321 ieee80211_rx_bss_put(local, bss);
322 }
323
324 static void
ieee80211_prepare_scan_chandef(struct cfg80211_chan_def * chandef,enum nl80211_bss_scan_width scan_width)325 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
326 enum nl80211_bss_scan_width scan_width)
327 {
328 memset(chandef, 0, sizeof(*chandef));
329 switch (scan_width) {
330 case NL80211_BSS_CHAN_WIDTH_5:
331 chandef->width = NL80211_CHAN_WIDTH_5;
332 break;
333 case NL80211_BSS_CHAN_WIDTH_10:
334 chandef->width = NL80211_CHAN_WIDTH_10;
335 break;
336 default:
337 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
338 break;
339 }
340 }
341
342 /* return false if no more work */
ieee80211_prep_hw_scan(struct ieee80211_sub_if_data * sdata)343 static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
344 {
345 struct ieee80211_local *local = sdata->local;
346 struct cfg80211_scan_request *req;
347 struct cfg80211_chan_def chandef;
348 u8 bands_used = 0;
349 int i, ielen, n_chans;
350 u32 flags = 0;
351
352 req = rcu_dereference_protected(local->scan_req,
353 lockdep_is_held(&local->mtx));
354
355 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
356 return false;
357
358 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
359 for (i = 0; i < req->n_channels; i++) {
360 local->hw_scan_req->req.channels[i] = req->channels[i];
361 bands_used |= BIT(req->channels[i]->band);
362 }
363
364 n_chans = req->n_channels;
365 } else {
366 do {
367 if (local->hw_scan_band == NUM_NL80211_BANDS)
368 return false;
369
370 n_chans = 0;
371
372 for (i = 0; i < req->n_channels; i++) {
373 if (req->channels[i]->band !=
374 local->hw_scan_band)
375 continue;
376 local->hw_scan_req->req.channels[n_chans] =
377 req->channels[i];
378 n_chans++;
379 bands_used |= BIT(req->channels[i]->band);
380 }
381
382 local->hw_scan_band++;
383 } while (!n_chans);
384 }
385
386 local->hw_scan_req->req.n_channels = n_chans;
387 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
388
389 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
390 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
391
392 ielen = ieee80211_build_preq_ies(sdata,
393 (u8 *)local->hw_scan_req->req.ie,
394 local->hw_scan_ies_bufsize,
395 &local->hw_scan_req->ies,
396 req->ie, req->ie_len,
397 bands_used, req->rates, &chandef,
398 flags);
399 local->hw_scan_req->req.ie_len = ielen;
400 local->hw_scan_req->req.no_cck = req->no_cck;
401 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
402 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
403 req->mac_addr_mask);
404 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
405
406 return true;
407 }
408
__ieee80211_scan_completed(struct ieee80211_hw * hw,bool aborted)409 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
410 {
411 struct ieee80211_local *local = hw_to_local(hw);
412 bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
413 bool was_scanning = local->scanning;
414 struct cfg80211_scan_request *scan_req;
415 struct ieee80211_sub_if_data *scan_sdata;
416 struct ieee80211_sub_if_data *sdata;
417
418 lockdep_assert_held(&local->mtx);
419
420 /*
421 * It's ok to abort a not-yet-running scan (that
422 * we have one at all will be verified by checking
423 * local->scan_req next), but not to complete it
424 * successfully.
425 */
426 if (WARN_ON(!local->scanning && !aborted))
427 aborted = true;
428
429 if (WARN_ON(!local->scan_req))
430 return;
431
432 scan_sdata = rcu_dereference_protected(local->scan_sdata,
433 lockdep_is_held(&local->mtx));
434
435 if (hw_scan && !aborted &&
436 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
437 ieee80211_prep_hw_scan(scan_sdata)) {
438 int rc;
439
440 rc = drv_hw_scan(local,
441 rcu_dereference_protected(local->scan_sdata,
442 lockdep_is_held(&local->mtx)),
443 local->hw_scan_req);
444
445 if (rc == 0)
446 return;
447
448 /* HW scan failed and is going to be reported as aborted,
449 * so clear old scan info.
450 */
451 memset(&local->scan_info, 0, sizeof(local->scan_info));
452 aborted = true;
453 }
454
455 kfree(local->hw_scan_req);
456 local->hw_scan_req = NULL;
457
458 scan_req = rcu_dereference_protected(local->scan_req,
459 lockdep_is_held(&local->mtx));
460
461 RCU_INIT_POINTER(local->scan_req, NULL);
462 RCU_INIT_POINTER(local->scan_sdata, NULL);
463
464 local->scanning = 0;
465 local->scan_chandef.chan = NULL;
466
467 synchronize_rcu();
468
469 if (scan_req != local->int_scan_req) {
470 local->scan_info.aborted = aborted;
471 cfg80211_scan_done(scan_req, &local->scan_info);
472 }
473
474 /* Set power back to normal operating levels. */
475 ieee80211_hw_config(local, 0);
476
477 if (!hw_scan && was_scanning) {
478 ieee80211_configure_filter(local);
479 drv_sw_scan_complete(local, scan_sdata);
480 ieee80211_offchannel_return(local);
481 }
482
483 ieee80211_recalc_idle(local);
484
485 ieee80211_mlme_notify_scan_completed(local);
486 ieee80211_ibss_notify_scan_completed(local);
487
488 /* Requeue all the work that might have been ignored while
489 * the scan was in progress; if there was none this will
490 * just be a no-op for the particular interface.
491 */
492 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
493 if (ieee80211_sdata_running(sdata))
494 wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
495 }
496
497 if (was_scanning)
498 ieee80211_start_next_roc(local);
499 }
500
ieee80211_scan_completed(struct ieee80211_hw * hw,struct cfg80211_scan_info * info)501 void ieee80211_scan_completed(struct ieee80211_hw *hw,
502 struct cfg80211_scan_info *info)
503 {
504 struct ieee80211_local *local = hw_to_local(hw);
505
506 trace_api_scan_completed(local, info->aborted);
507
508 set_bit(SCAN_COMPLETED, &local->scanning);
509 if (info->aborted)
510 set_bit(SCAN_ABORTED, &local->scanning);
511
512 memcpy(&local->scan_info, info, sizeof(*info));
513
514 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
515 }
516 EXPORT_SYMBOL(ieee80211_scan_completed);
517
ieee80211_start_sw_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)518 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
519 struct ieee80211_sub_if_data *sdata)
520 {
521 /* Software scan is not supported in multi-channel cases */
522 if (local->use_chanctx)
523 return -EOPNOTSUPP;
524
525 /*
526 * Hardware/driver doesn't support hw_scan, so use software
527 * scanning instead. First send a nullfunc frame with power save
528 * bit on so that AP will buffer the frames for us while we are not
529 * listening, then send probe requests to each channel and wait for
530 * the responses. After all channels are scanned, tune back to the
531 * original channel and send a nullfunc frame with power save bit
532 * off to trigger the AP to send us all the buffered frames.
533 *
534 * Note that while local->sw_scanning is true everything else but
535 * nullfunc frames and probe requests will be dropped in
536 * ieee80211_tx_h_check_assoc().
537 */
538 drv_sw_scan_start(local, sdata, local->scan_addr);
539
540 local->leave_oper_channel_time = jiffies;
541 local->next_scan_state = SCAN_DECISION;
542 local->scan_channel_idx = 0;
543
544 ieee80211_offchannel_stop_vifs(local);
545
546 /* ensure nullfunc is transmitted before leaving operating channel */
547 ieee80211_flush_queues(local, NULL, false);
548
549 ieee80211_configure_filter(local);
550
551 /* We need to set power level at maximum rate for scanning. */
552 ieee80211_hw_config(local, 0);
553
554 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
555
556 return 0;
557 }
558
__ieee80211_can_leave_ch(struct ieee80211_sub_if_data * sdata)559 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
560 {
561 struct ieee80211_local *local = sdata->local;
562 struct ieee80211_sub_if_data *sdata_iter;
563
564 if (!ieee80211_is_radar_required(local))
565 return true;
566
567 if (!regulatory_pre_cac_allowed(local->hw.wiphy))
568 return false;
569
570 mutex_lock(&local->iflist_mtx);
571 list_for_each_entry(sdata_iter, &local->interfaces, list) {
572 if (sdata_iter->wdev.cac_started) {
573 mutex_unlock(&local->iflist_mtx);
574 return false;
575 }
576 }
577 mutex_unlock(&local->iflist_mtx);
578
579 return true;
580 }
581
ieee80211_can_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)582 static bool ieee80211_can_scan(struct ieee80211_local *local,
583 struct ieee80211_sub_if_data *sdata)
584 {
585 if (!__ieee80211_can_leave_ch(sdata))
586 return false;
587
588 if (!list_empty(&local->roc_list))
589 return false;
590
591 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
592 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
593 return false;
594
595 return true;
596 }
597
ieee80211_run_deferred_scan(struct ieee80211_local * local)598 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
599 {
600 lockdep_assert_held(&local->mtx);
601
602 if (!local->scan_req || local->scanning)
603 return;
604
605 if (!ieee80211_can_scan(local,
606 rcu_dereference_protected(
607 local->scan_sdata,
608 lockdep_is_held(&local->mtx))))
609 return;
610
611 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
612 round_jiffies_relative(0));
613 }
614
ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data * sdata,const u8 * src,const u8 * dst,const u8 * ssid,size_t ssid_len,const u8 * ie,size_t ie_len,u32 ratemask,u32 flags,u32 tx_flags,struct ieee80211_channel * channel)615 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
616 const u8 *src, const u8 *dst,
617 const u8 *ssid, size_t ssid_len,
618 const u8 *ie, size_t ie_len,
619 u32 ratemask, u32 flags, u32 tx_flags,
620 struct ieee80211_channel *channel)
621 {
622 struct sk_buff *skb;
623
624 skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
625 ssid, ssid_len,
626 ie, ie_len, flags);
627
628 if (skb) {
629 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
630 struct ieee80211_hdr *hdr = (void *)skb->data;
631 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
632 u16 sn = get_random_u16();
633
634 info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
635 hdr->seq_ctrl =
636 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
637 }
638 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
639 IEEE80211_SKB_CB(skb)->control.flags |= IEEE80211_TX_CTRL_SCAN_TX;
640 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
641 }
642 }
643
ieee80211_scan_state_send_probe(struct ieee80211_local * local,unsigned long * next_delay)644 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
645 unsigned long *next_delay)
646 {
647 int i;
648 struct ieee80211_sub_if_data *sdata;
649 struct cfg80211_scan_request *scan_req;
650 enum nl80211_band band = local->hw.conf.chandef.chan->band;
651 u32 flags = 0, tx_flags;
652
653 scan_req = rcu_dereference_protected(local->scan_req,
654 lockdep_is_held(&local->mtx));
655
656 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
657 if (scan_req->no_cck)
658 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
659 if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
660 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
661 if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
662 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
663
664 sdata = rcu_dereference_protected(local->scan_sdata,
665 lockdep_is_held(&local->mtx));
666
667 for (i = 0; i < scan_req->n_ssids; i++)
668 ieee80211_send_scan_probe_req(
669 sdata, local->scan_addr, scan_req->bssid,
670 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
671 scan_req->ie, scan_req->ie_len,
672 scan_req->rates[band], flags,
673 tx_flags, local->hw.conf.chandef.chan);
674
675 /*
676 * After sending probe requests, wait for probe responses
677 * on the channel.
678 */
679 *next_delay = IEEE80211_CHANNEL_TIME;
680 local->next_scan_state = SCAN_DECISION;
681 }
682
__ieee80211_start_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)683 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
684 struct cfg80211_scan_request *req)
685 {
686 struct ieee80211_local *local = sdata->local;
687 bool hw_scan = local->ops->hw_scan;
688 int rc;
689
690 lockdep_assert_held(&local->mtx);
691
692 if (local->scan_req)
693 return -EBUSY;
694
695 if (!__ieee80211_can_leave_ch(sdata))
696 return -EBUSY;
697
698 if (!ieee80211_can_scan(local, sdata)) {
699 /* wait for the work to finish/time out */
700 rcu_assign_pointer(local->scan_req, req);
701 rcu_assign_pointer(local->scan_sdata, sdata);
702 return 0;
703 }
704
705 again:
706 if (hw_scan) {
707 u8 *ies;
708
709 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
710
711 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
712 int i, n_bands = 0;
713 u8 bands_counted = 0;
714
715 for (i = 0; i < req->n_channels; i++) {
716 if (bands_counted & BIT(req->channels[i]->band))
717 continue;
718 bands_counted |= BIT(req->channels[i]->band);
719 n_bands++;
720 }
721
722 local->hw_scan_ies_bufsize *= n_bands;
723 }
724
725 local->hw_scan_req = kmalloc(
726 sizeof(*local->hw_scan_req) +
727 req->n_channels * sizeof(req->channels[0]) +
728 local->hw_scan_ies_bufsize, GFP_KERNEL);
729 if (!local->hw_scan_req)
730 return -ENOMEM;
731
732 local->hw_scan_req->req.ssids = req->ssids;
733 local->hw_scan_req->req.n_ssids = req->n_ssids;
734 ies = (u8 *)local->hw_scan_req +
735 sizeof(*local->hw_scan_req) +
736 req->n_channels * sizeof(req->channels[0]);
737 local->hw_scan_req->req.ie = ies;
738 local->hw_scan_req->req.flags = req->flags;
739 eth_broadcast_addr(local->hw_scan_req->req.bssid);
740 local->hw_scan_req->req.duration = req->duration;
741 local->hw_scan_req->req.duration_mandatory =
742 req->duration_mandatory;
743
744 local->hw_scan_band = 0;
745 local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
746 local->hw_scan_req->req.scan_6ghz_params =
747 req->scan_6ghz_params;
748 local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
749
750 /*
751 * After allocating local->hw_scan_req, we must
752 * go through until ieee80211_prep_hw_scan(), so
753 * anything that might be changed here and leave
754 * this function early must not go after this
755 * allocation.
756 */
757 }
758
759 rcu_assign_pointer(local->scan_req, req);
760 rcu_assign_pointer(local->scan_sdata, sdata);
761
762 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
763 get_random_mask_addr(local->scan_addr,
764 req->mac_addr,
765 req->mac_addr_mask);
766 else
767 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
768
769 if (hw_scan) {
770 __set_bit(SCAN_HW_SCANNING, &local->scanning);
771 } else if ((req->n_channels == 1) &&
772 (req->channels[0] == local->_oper_chandef.chan)) {
773 /*
774 * If we are scanning only on the operating channel
775 * then we do not need to stop normal activities
776 */
777 unsigned long next_delay;
778
779 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
780
781 ieee80211_recalc_idle(local);
782
783 /* Notify driver scan is starting, keep order of operations
784 * same as normal software scan, in case that matters. */
785 drv_sw_scan_start(local, sdata, local->scan_addr);
786
787 ieee80211_configure_filter(local); /* accept probe-responses */
788
789 /* We need to ensure power level is at max for scanning. */
790 ieee80211_hw_config(local, 0);
791
792 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
793 IEEE80211_CHAN_RADAR)) ||
794 !req->n_ssids) {
795 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
796 if (req->n_ssids)
797 set_bit(SCAN_BEACON_WAIT, &local->scanning);
798 } else {
799 ieee80211_scan_state_send_probe(local, &next_delay);
800 next_delay = IEEE80211_CHANNEL_TIME;
801 }
802
803 /* Now, just wait a bit and we are all done! */
804 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
805 next_delay);
806 return 0;
807 } else {
808 /* Do normal software scan */
809 __set_bit(SCAN_SW_SCANNING, &local->scanning);
810 }
811
812 ieee80211_recalc_idle(local);
813
814 if (hw_scan) {
815 WARN_ON(!ieee80211_prep_hw_scan(sdata));
816 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
817 } else {
818 rc = ieee80211_start_sw_scan(local, sdata);
819 }
820
821 if (rc) {
822 kfree(local->hw_scan_req);
823 local->hw_scan_req = NULL;
824 local->scanning = 0;
825
826 ieee80211_recalc_idle(local);
827
828 local->scan_req = NULL;
829 RCU_INIT_POINTER(local->scan_sdata, NULL);
830 }
831
832 if (hw_scan && rc == 1) {
833 /*
834 * we can't fall back to software for P2P-GO
835 * as it must update NoA etc.
836 */
837 if (ieee80211_vif_type_p2p(&sdata->vif) ==
838 NL80211_IFTYPE_P2P_GO)
839 return -EOPNOTSUPP;
840 hw_scan = false;
841 goto again;
842 }
843
844 return rc;
845 }
846
847 static unsigned long
ieee80211_scan_get_channel_time(struct ieee80211_channel * chan)848 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
849 {
850 /*
851 * TODO: channel switching also consumes quite some time,
852 * add that delay as well to get a better estimation
853 */
854 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
855 return IEEE80211_PASSIVE_CHANNEL_TIME;
856 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
857 }
858
ieee80211_scan_state_decision(struct ieee80211_local * local,unsigned long * next_delay)859 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
860 unsigned long *next_delay)
861 {
862 bool associated = false;
863 bool tx_empty = true;
864 bool bad_latency;
865 struct ieee80211_sub_if_data *sdata;
866 struct ieee80211_channel *next_chan;
867 enum mac80211_scan_state next_scan_state;
868 struct cfg80211_scan_request *scan_req;
869
870 /*
871 * check if at least one STA interface is associated,
872 * check if at least one STA interface has pending tx frames
873 * and grab the lowest used beacon interval
874 */
875 mutex_lock(&local->iflist_mtx);
876 list_for_each_entry(sdata, &local->interfaces, list) {
877 if (!ieee80211_sdata_running(sdata))
878 continue;
879
880 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
881 if (sdata->u.mgd.associated) {
882 associated = true;
883
884 if (!qdisc_all_tx_empty(sdata->dev)) {
885 tx_empty = false;
886 break;
887 }
888 }
889 }
890 }
891 mutex_unlock(&local->iflist_mtx);
892
893 scan_req = rcu_dereference_protected(local->scan_req,
894 lockdep_is_held(&local->mtx));
895
896 next_chan = scan_req->channels[local->scan_channel_idx];
897
898 /*
899 * we're currently scanning a different channel, let's
900 * see if we can scan another channel without interfering
901 * with the current traffic situation.
902 *
903 * Keep good latency, do not stay off-channel more than 125 ms.
904 */
905
906 bad_latency = time_after(jiffies +
907 ieee80211_scan_get_channel_time(next_chan),
908 local->leave_oper_channel_time + HZ / 8);
909
910 if (associated && !tx_empty) {
911 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
912 next_scan_state = SCAN_ABORT;
913 else
914 next_scan_state = SCAN_SUSPEND;
915 } else if (associated && bad_latency) {
916 next_scan_state = SCAN_SUSPEND;
917 } else {
918 next_scan_state = SCAN_SET_CHANNEL;
919 }
920
921 local->next_scan_state = next_scan_state;
922
923 *next_delay = 0;
924 }
925
ieee80211_scan_state_set_channel(struct ieee80211_local * local,unsigned long * next_delay)926 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
927 unsigned long *next_delay)
928 {
929 int skip;
930 struct ieee80211_channel *chan;
931 enum nl80211_bss_scan_width oper_scan_width;
932 struct cfg80211_scan_request *scan_req;
933
934 scan_req = rcu_dereference_protected(local->scan_req,
935 lockdep_is_held(&local->mtx));
936
937 skip = 0;
938 chan = scan_req->channels[local->scan_channel_idx];
939
940 local->scan_chandef.chan = chan;
941 local->scan_chandef.center_freq1 = chan->center_freq;
942 local->scan_chandef.freq1_offset = chan->freq_offset;
943 local->scan_chandef.center_freq2 = 0;
944
945 /* For scanning on the S1G band, ignore scan_width (which is constant
946 * across all channels) for now since channel width is specific to each
947 * channel. Detect the required channel width here and likely revisit
948 * later. Maybe scan_width could be used to build the channel scan list?
949 */
950 if (chan->band == NL80211_BAND_S1GHZ) {
951 local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
952 goto set_channel;
953 }
954
955 switch (scan_req->scan_width) {
956 case NL80211_BSS_CHAN_WIDTH_5:
957 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
958 break;
959 case NL80211_BSS_CHAN_WIDTH_10:
960 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
961 break;
962 default:
963 case NL80211_BSS_CHAN_WIDTH_20:
964 /* If scanning on oper channel, use whatever channel-type
965 * is currently in use.
966 */
967 oper_scan_width = cfg80211_chandef_to_scan_width(
968 &local->_oper_chandef);
969 if (chan == local->_oper_chandef.chan &&
970 oper_scan_width == scan_req->scan_width)
971 local->scan_chandef = local->_oper_chandef;
972 else
973 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
974 break;
975 case NL80211_BSS_CHAN_WIDTH_1:
976 case NL80211_BSS_CHAN_WIDTH_2:
977 /* shouldn't get here, S1G handled above */
978 WARN_ON(1);
979 break;
980 }
981
982 set_channel:
983 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
984 skip = 1;
985
986 /* advance state machine to next channel/band */
987 local->scan_channel_idx++;
988
989 if (skip) {
990 /* if we skip this channel return to the decision state */
991 local->next_scan_state = SCAN_DECISION;
992 return;
993 }
994
995 /*
996 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
997 * (which unfortunately doesn't say _why_ step a) is done,
998 * but it waits for the probe delay or until a frame is
999 * received - and the received frame would update the NAV).
1000 * For now, we do not support waiting until a frame is
1001 * received.
1002 *
1003 * In any case, it is not necessary for a passive scan.
1004 */
1005 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
1006 !scan_req->n_ssids) {
1007 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
1008 local->next_scan_state = SCAN_DECISION;
1009 if (scan_req->n_ssids)
1010 set_bit(SCAN_BEACON_WAIT, &local->scanning);
1011 return;
1012 }
1013
1014 /* active scan, send probes */
1015 *next_delay = IEEE80211_PROBE_DELAY;
1016 local->next_scan_state = SCAN_SEND_PROBE;
1017 }
1018
ieee80211_scan_state_suspend(struct ieee80211_local * local,unsigned long * next_delay)1019 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1020 unsigned long *next_delay)
1021 {
1022 /* switch back to the operating channel */
1023 local->scan_chandef.chan = NULL;
1024 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
1025
1026 /* disable PS */
1027 ieee80211_offchannel_return(local);
1028
1029 *next_delay = HZ / 5;
1030 /* afterwards, resume scan & go to next channel */
1031 local->next_scan_state = SCAN_RESUME;
1032 }
1033
ieee80211_scan_state_resume(struct ieee80211_local * local,unsigned long * next_delay)1034 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1035 unsigned long *next_delay)
1036 {
1037 ieee80211_offchannel_stop_vifs(local);
1038
1039 if (local->ops->flush) {
1040 ieee80211_flush_queues(local, NULL, false);
1041 *next_delay = 0;
1042 } else
1043 *next_delay = HZ / 10;
1044
1045 /* remember when we left the operating channel */
1046 local->leave_oper_channel_time = jiffies;
1047
1048 /* advance to the next channel to be scanned */
1049 local->next_scan_state = SCAN_SET_CHANNEL;
1050 }
1051
ieee80211_scan_work(struct wiphy * wiphy,struct wiphy_work * work)1052 void ieee80211_scan_work(struct wiphy *wiphy, struct wiphy_work *work)
1053 {
1054 struct ieee80211_local *local =
1055 container_of(work, struct ieee80211_local, scan_work.work);
1056 struct ieee80211_sub_if_data *sdata;
1057 struct cfg80211_scan_request *scan_req;
1058 unsigned long next_delay = 0;
1059 bool aborted;
1060
1061 mutex_lock(&local->mtx);
1062
1063 if (!ieee80211_can_run_worker(local)) {
1064 aborted = true;
1065 goto out_complete;
1066 }
1067
1068 sdata = rcu_dereference_protected(local->scan_sdata,
1069 lockdep_is_held(&local->mtx));
1070 scan_req = rcu_dereference_protected(local->scan_req,
1071 lockdep_is_held(&local->mtx));
1072
1073 /* When scanning on-channel, the first-callback means completed. */
1074 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1075 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1076 goto out_complete;
1077 }
1078
1079 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1080 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1081 goto out_complete;
1082 }
1083
1084 if (!sdata || !scan_req)
1085 goto out;
1086
1087 if (!local->scanning) {
1088 int rc;
1089
1090 RCU_INIT_POINTER(local->scan_req, NULL);
1091 RCU_INIT_POINTER(local->scan_sdata, NULL);
1092
1093 rc = __ieee80211_start_scan(sdata, scan_req);
1094 if (rc) {
1095 /* need to complete scan in cfg80211 */
1096 rcu_assign_pointer(local->scan_req, scan_req);
1097 aborted = true;
1098 goto out_complete;
1099 } else
1100 goto out;
1101 }
1102
1103 clear_bit(SCAN_BEACON_WAIT, &local->scanning);
1104
1105 /*
1106 * as long as no delay is required advance immediately
1107 * without scheduling a new work
1108 */
1109 do {
1110 if (!ieee80211_sdata_running(sdata)) {
1111 aborted = true;
1112 goto out_complete;
1113 }
1114
1115 if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) &&
1116 local->next_scan_state == SCAN_DECISION)
1117 local->next_scan_state = SCAN_SEND_PROBE;
1118
1119 switch (local->next_scan_state) {
1120 case SCAN_DECISION:
1121 /* if no more bands/channels left, complete scan */
1122 if (local->scan_channel_idx >= scan_req->n_channels) {
1123 aborted = false;
1124 goto out_complete;
1125 }
1126 ieee80211_scan_state_decision(local, &next_delay);
1127 break;
1128 case SCAN_SET_CHANNEL:
1129 ieee80211_scan_state_set_channel(local, &next_delay);
1130 break;
1131 case SCAN_SEND_PROBE:
1132 ieee80211_scan_state_send_probe(local, &next_delay);
1133 break;
1134 case SCAN_SUSPEND:
1135 ieee80211_scan_state_suspend(local, &next_delay);
1136 break;
1137 case SCAN_RESUME:
1138 ieee80211_scan_state_resume(local, &next_delay);
1139 break;
1140 case SCAN_ABORT:
1141 aborted = true;
1142 goto out_complete;
1143 }
1144 } while (next_delay == 0);
1145
1146 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
1147 next_delay);
1148 goto out;
1149
1150 out_complete:
1151 __ieee80211_scan_completed(&local->hw, aborted);
1152 out:
1153 mutex_unlock(&local->mtx);
1154 }
1155
ieee80211_request_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)1156 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1157 struct cfg80211_scan_request *req)
1158 {
1159 int res;
1160
1161 mutex_lock(&sdata->local->mtx);
1162 res = __ieee80211_start_scan(sdata, req);
1163 mutex_unlock(&sdata->local->mtx);
1164
1165 return res;
1166 }
1167
ieee80211_request_ibss_scan(struct ieee80211_sub_if_data * sdata,const u8 * ssid,u8 ssid_len,struct ieee80211_channel ** channels,unsigned int n_channels,enum nl80211_bss_scan_width scan_width)1168 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1169 const u8 *ssid, u8 ssid_len,
1170 struct ieee80211_channel **channels,
1171 unsigned int n_channels,
1172 enum nl80211_bss_scan_width scan_width)
1173 {
1174 struct ieee80211_local *local = sdata->local;
1175 int ret = -EBUSY, i, n_ch = 0;
1176 enum nl80211_band band;
1177
1178 mutex_lock(&local->mtx);
1179
1180 /* busy scanning */
1181 if (local->scan_req)
1182 goto unlock;
1183
1184 /* fill internal scan request */
1185 if (!channels) {
1186 int max_n;
1187
1188 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1189 if (!local->hw.wiphy->bands[band] ||
1190 band == NL80211_BAND_6GHZ)
1191 continue;
1192
1193 max_n = local->hw.wiphy->bands[band]->n_channels;
1194 for (i = 0; i < max_n; i++) {
1195 struct ieee80211_channel *tmp_ch =
1196 &local->hw.wiphy->bands[band]->channels[i];
1197
1198 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1199 IEEE80211_CHAN_DISABLED))
1200 continue;
1201
1202 local->int_scan_req->channels[n_ch] = tmp_ch;
1203 n_ch++;
1204 }
1205 }
1206
1207 if (WARN_ON_ONCE(n_ch == 0))
1208 goto unlock;
1209
1210 local->int_scan_req->n_channels = n_ch;
1211 } else {
1212 for (i = 0; i < n_channels; i++) {
1213 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1214 IEEE80211_CHAN_DISABLED))
1215 continue;
1216
1217 local->int_scan_req->channels[n_ch] = channels[i];
1218 n_ch++;
1219 }
1220
1221 if (WARN_ON_ONCE(n_ch == 0))
1222 goto unlock;
1223
1224 local->int_scan_req->n_channels = n_ch;
1225 }
1226
1227 local->int_scan_req->ssids = &local->scan_ssid;
1228 local->int_scan_req->n_ssids = 1;
1229 local->int_scan_req->scan_width = scan_width;
1230 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1231 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1232
1233 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1234 unlock:
1235 mutex_unlock(&local->mtx);
1236 return ret;
1237 }
1238
ieee80211_scan_cancel(struct ieee80211_local * local)1239 void ieee80211_scan_cancel(struct ieee80211_local *local)
1240 {
1241 /* ensure a new scan cannot be queued */
1242 lockdep_assert_wiphy(local->hw.wiphy);
1243
1244 /*
1245 * We are canceling software scan, or deferred scan that was not
1246 * yet really started (see __ieee80211_start_scan ).
1247 *
1248 * Regarding hardware scan:
1249 * - we can not call __ieee80211_scan_completed() as when
1250 * SCAN_HW_SCANNING bit is set this function change
1251 * local->hw_scan_req to operate on 5G band, what race with
1252 * driver which can use local->hw_scan_req
1253 *
1254 * - we can not cancel scan_work since driver can schedule it
1255 * by ieee80211_scan_completed(..., true) to finish scan
1256 *
1257 * Hence we only call the cancel_hw_scan() callback, but the low-level
1258 * driver is still responsible for calling ieee80211_scan_completed()
1259 * after the scan was completed/aborted.
1260 */
1261
1262 mutex_lock(&local->mtx);
1263 if (!local->scan_req)
1264 goto out;
1265
1266 /*
1267 * We have a scan running and the driver already reported completion,
1268 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1269 * cancelled.
1270 */
1271 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1272 test_bit(SCAN_COMPLETED, &local->scanning)) {
1273 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1274 goto out;
1275 }
1276
1277 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1278 /*
1279 * Make sure that __ieee80211_scan_completed doesn't trigger a
1280 * scan on another band.
1281 */
1282 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1283 if (local->ops->cancel_hw_scan)
1284 drv_cancel_hw_scan(local,
1285 rcu_dereference_protected(local->scan_sdata,
1286 lockdep_is_held(&local->mtx)));
1287 goto out;
1288 }
1289
1290 wiphy_delayed_work_cancel(local->hw.wiphy, &local->scan_work);
1291 /* and clean up */
1292 memset(&local->scan_info, 0, sizeof(local->scan_info));
1293 __ieee80211_scan_completed(&local->hw, true);
1294 out:
1295 mutex_unlock(&local->mtx);
1296 }
1297
__ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1298 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1299 struct cfg80211_sched_scan_request *req)
1300 {
1301 struct ieee80211_local *local = sdata->local;
1302 struct ieee80211_scan_ies sched_scan_ies = {};
1303 struct cfg80211_chan_def chandef;
1304 int ret, i, iebufsz, num_bands = 0;
1305 u32 rate_masks[NUM_NL80211_BANDS] = {};
1306 u8 bands_used = 0;
1307 u8 *ie;
1308 u32 flags = 0;
1309
1310 iebufsz = local->scan_ies_len + req->ie_len;
1311
1312 lockdep_assert_held(&local->mtx);
1313
1314 if (!local->ops->sched_scan_start)
1315 return -ENOTSUPP;
1316
1317 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1318 if (local->hw.wiphy->bands[i]) {
1319 bands_used |= BIT(i);
1320 rate_masks[i] = (u32) -1;
1321 num_bands++;
1322 }
1323 }
1324
1325 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1326 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1327
1328 ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1329 if (!ie) {
1330 ret = -ENOMEM;
1331 goto out;
1332 }
1333
1334 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1335
1336 ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1337 &sched_scan_ies, req->ie,
1338 req->ie_len, bands_used, rate_masks, &chandef,
1339 flags);
1340
1341 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1342 if (ret == 0) {
1343 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1344 rcu_assign_pointer(local->sched_scan_req, req);
1345 }
1346
1347 kfree(ie);
1348
1349 out:
1350 if (ret) {
1351 /* Clean in case of failure after HW restart or upon resume. */
1352 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1353 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1354 }
1355
1356 return ret;
1357 }
1358
ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1359 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1360 struct cfg80211_sched_scan_request *req)
1361 {
1362 struct ieee80211_local *local = sdata->local;
1363 int ret;
1364
1365 mutex_lock(&local->mtx);
1366
1367 if (rcu_access_pointer(local->sched_scan_sdata)) {
1368 mutex_unlock(&local->mtx);
1369 return -EBUSY;
1370 }
1371
1372 ret = __ieee80211_request_sched_scan_start(sdata, req);
1373
1374 mutex_unlock(&local->mtx);
1375 return ret;
1376 }
1377
ieee80211_request_sched_scan_stop(struct ieee80211_local * local)1378 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1379 {
1380 struct ieee80211_sub_if_data *sched_scan_sdata;
1381 int ret = -ENOENT;
1382
1383 mutex_lock(&local->mtx);
1384
1385 if (!local->ops->sched_scan_stop) {
1386 ret = -ENOTSUPP;
1387 goto out;
1388 }
1389
1390 /* We don't want to restart sched scan anymore. */
1391 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1392
1393 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1394 lockdep_is_held(&local->mtx));
1395 if (sched_scan_sdata) {
1396 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1397 if (!ret)
1398 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1399 }
1400 out:
1401 mutex_unlock(&local->mtx);
1402
1403 return ret;
1404 }
1405
ieee80211_sched_scan_results(struct ieee80211_hw * hw)1406 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1407 {
1408 struct ieee80211_local *local = hw_to_local(hw);
1409
1410 trace_api_sched_scan_results(local);
1411
1412 cfg80211_sched_scan_results(hw->wiphy, 0);
1413 }
1414 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1415
ieee80211_sched_scan_end(struct ieee80211_local * local)1416 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1417 {
1418 mutex_lock(&local->mtx);
1419
1420 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1421 mutex_unlock(&local->mtx);
1422 return;
1423 }
1424
1425 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1426
1427 /* If sched scan was aborted by the driver. */
1428 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1429
1430 mutex_unlock(&local->mtx);
1431
1432 cfg80211_sched_scan_stopped_locked(local->hw.wiphy, 0);
1433 }
1434
ieee80211_sched_scan_stopped_work(struct wiphy * wiphy,struct wiphy_work * work)1435 void ieee80211_sched_scan_stopped_work(struct wiphy *wiphy,
1436 struct wiphy_work *work)
1437 {
1438 struct ieee80211_local *local =
1439 container_of(work, struct ieee80211_local,
1440 sched_scan_stopped_work);
1441
1442 ieee80211_sched_scan_end(local);
1443 }
1444
ieee80211_sched_scan_stopped(struct ieee80211_hw * hw)1445 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1446 {
1447 struct ieee80211_local *local = hw_to_local(hw);
1448
1449 trace_api_sched_scan_stopped(local);
1450
1451 /*
1452 * this shouldn't really happen, so for simplicity
1453 * simply ignore it, and let mac80211 reconfigure
1454 * the sched scan later on.
1455 */
1456 if (local->in_reconfig)
1457 return;
1458
1459 wiphy_work_queue(hw->wiphy, &local->sched_scan_stopped_work);
1460 }
1461 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
1462