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;
350 u32 *n_chans;
351 u32 flags = 0;
352
353 req = rcu_dereference_protected(local->scan_req,
354 lockdep_is_held(&local->mtx));
355
356 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
357 return false;
358
359 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
360 local->hw_scan_req->req.n_channels = req->n_channels;
361
362 for (i = 0; i < req->n_channels; i++) {
363 local->hw_scan_req->req.channels[i] = req->channels[i];
364 bands_used |= BIT(req->channels[i]->band);
365 }
366 } else {
367 do {
368 if (local->hw_scan_band == NUM_NL80211_BANDS)
369 return false;
370
371 n_chans = &local->hw_scan_req->req.n_channels;
372 *n_chans = 0;
373
374 for (i = 0; i < req->n_channels; i++) {
375 if (req->channels[i]->band !=
376 local->hw_scan_band)
377 continue;
378 local->hw_scan_req->req.channels[(*n_chans)++] =
379 req->channels[i];
380
381 bands_used |= BIT(req->channels[i]->band);
382 }
383
384 local->hw_scan_band++;
385 } while (!*n_chans);
386 }
387
388 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
389
390 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
391 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
392
393 ielen = ieee80211_build_preq_ies(sdata,
394 (u8 *)local->hw_scan_req->req.ie,
395 local->hw_scan_ies_bufsize,
396 &local->hw_scan_req->ies,
397 req->ie, req->ie_len,
398 bands_used, req->rates, &chandef,
399 flags);
400 local->hw_scan_req->req.ie_len = ielen;
401 local->hw_scan_req->req.no_cck = req->no_cck;
402 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
403 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
404 req->mac_addr_mask);
405 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
406
407 return true;
408 }
409
__ieee80211_scan_completed(struct ieee80211_hw * hw,bool aborted)410 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
411 {
412 struct ieee80211_local *local = hw_to_local(hw);
413 bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
414 bool was_scanning = local->scanning;
415 struct cfg80211_scan_request *scan_req;
416 struct ieee80211_sub_if_data *scan_sdata;
417 struct ieee80211_sub_if_data *sdata;
418
419 lockdep_assert_held(&local->mtx);
420
421 /*
422 * It's ok to abort a not-yet-running scan (that
423 * we have one at all will be verified by checking
424 * local->scan_req next), but not to complete it
425 * successfully.
426 */
427 if (WARN_ON(!local->scanning && !aborted))
428 aborted = true;
429
430 if (WARN_ON(!local->scan_req))
431 return;
432
433 scan_sdata = rcu_dereference_protected(local->scan_sdata,
434 lockdep_is_held(&local->mtx));
435
436 if (hw_scan && !aborted &&
437 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
438 ieee80211_prep_hw_scan(scan_sdata)) {
439 int rc;
440
441 rc = drv_hw_scan(local,
442 rcu_dereference_protected(local->scan_sdata,
443 lockdep_is_held(&local->mtx)),
444 local->hw_scan_req);
445
446 if (rc == 0)
447 return;
448
449 /* HW scan failed and is going to be reported as aborted,
450 * so clear old scan info.
451 */
452 memset(&local->scan_info, 0, sizeof(local->scan_info));
453 aborted = true;
454 }
455
456 kfree(local->hw_scan_req);
457 local->hw_scan_req = NULL;
458
459 scan_req = rcu_dereference_protected(local->scan_req,
460 lockdep_is_held(&local->mtx));
461
462 RCU_INIT_POINTER(local->scan_req, NULL);
463 RCU_INIT_POINTER(local->scan_sdata, NULL);
464
465 local->scanning = 0;
466 local->scan_chandef.chan = NULL;
467
468 synchronize_rcu();
469
470 if (scan_req != local->int_scan_req) {
471 local->scan_info.aborted = aborted;
472 cfg80211_scan_done(scan_req, &local->scan_info);
473 }
474
475 /* Set power back to normal operating levels. */
476 ieee80211_hw_config(local, 0);
477
478 if (!hw_scan && was_scanning) {
479 ieee80211_configure_filter(local);
480 drv_sw_scan_complete(local, scan_sdata);
481 ieee80211_offchannel_return(local);
482 }
483
484 ieee80211_recalc_idle(local);
485
486 ieee80211_mlme_notify_scan_completed(local);
487 ieee80211_ibss_notify_scan_completed(local);
488
489 /* Requeue all the work that might have been ignored while
490 * the scan was in progress; if there was none this will
491 * just be a no-op for the particular interface.
492 */
493 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
494 if (ieee80211_sdata_running(sdata))
495 wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
496 }
497
498 if (was_scanning)
499 ieee80211_start_next_roc(local);
500 }
501
ieee80211_scan_completed(struct ieee80211_hw * hw,struct cfg80211_scan_info * info)502 void ieee80211_scan_completed(struct ieee80211_hw *hw,
503 struct cfg80211_scan_info *info)
504 {
505 struct ieee80211_local *local = hw_to_local(hw);
506
507 trace_api_scan_completed(local, info->aborted);
508
509 set_bit(SCAN_COMPLETED, &local->scanning);
510 if (info->aborted)
511 set_bit(SCAN_ABORTED, &local->scanning);
512
513 memcpy(&local->scan_info, info, sizeof(*info));
514
515 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
516 }
517 EXPORT_SYMBOL(ieee80211_scan_completed);
518
ieee80211_start_sw_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)519 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
520 struct ieee80211_sub_if_data *sdata)
521 {
522 /* Software scan is not supported in multi-channel cases */
523 if (local->use_chanctx)
524 return -EOPNOTSUPP;
525
526 /*
527 * Hardware/driver doesn't support hw_scan, so use software
528 * scanning instead. First send a nullfunc frame with power save
529 * bit on so that AP will buffer the frames for us while we are not
530 * listening, then send probe requests to each channel and wait for
531 * the responses. After all channels are scanned, tune back to the
532 * original channel and send a nullfunc frame with power save bit
533 * off to trigger the AP to send us all the buffered frames.
534 *
535 * Note that while local->sw_scanning is true everything else but
536 * nullfunc frames and probe requests will be dropped in
537 * ieee80211_tx_h_check_assoc().
538 */
539 drv_sw_scan_start(local, sdata, local->scan_addr);
540
541 local->leave_oper_channel_time = jiffies;
542 local->next_scan_state = SCAN_DECISION;
543 local->scan_channel_idx = 0;
544
545 ieee80211_offchannel_stop_vifs(local);
546
547 /* ensure nullfunc is transmitted before leaving operating channel */
548 ieee80211_flush_queues(local, NULL, false);
549
550 ieee80211_configure_filter(local);
551
552 /* We need to set power level at maximum rate for scanning. */
553 ieee80211_hw_config(local, 0);
554
555 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
556
557 return 0;
558 }
559
__ieee80211_can_leave_ch(struct ieee80211_sub_if_data * sdata)560 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
561 {
562 struct ieee80211_local *local = sdata->local;
563 struct ieee80211_sub_if_data *sdata_iter;
564
565 if (!ieee80211_is_radar_required(local))
566 return true;
567
568 if (!regulatory_pre_cac_allowed(local->hw.wiphy))
569 return false;
570
571 mutex_lock(&local->iflist_mtx);
572 list_for_each_entry(sdata_iter, &local->interfaces, list) {
573 if (sdata_iter->wdev.cac_started) {
574 mutex_unlock(&local->iflist_mtx);
575 return false;
576 }
577 }
578 mutex_unlock(&local->iflist_mtx);
579
580 return true;
581 }
582
ieee80211_can_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)583 static bool ieee80211_can_scan(struct ieee80211_local *local,
584 struct ieee80211_sub_if_data *sdata)
585 {
586 if (!__ieee80211_can_leave_ch(sdata))
587 return false;
588
589 if (!list_empty(&local->roc_list))
590 return false;
591
592 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
593 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
594 return false;
595
596 return true;
597 }
598
ieee80211_run_deferred_scan(struct ieee80211_local * local)599 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
600 {
601 lockdep_assert_held(&local->mtx);
602
603 if (!local->scan_req || local->scanning)
604 return;
605
606 if (!ieee80211_can_scan(local,
607 rcu_dereference_protected(
608 local->scan_sdata,
609 lockdep_is_held(&local->mtx))))
610 return;
611
612 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
613 round_jiffies_relative(0));
614 }
615
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)616 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
617 const u8 *src, const u8 *dst,
618 const u8 *ssid, size_t ssid_len,
619 const u8 *ie, size_t ie_len,
620 u32 ratemask, u32 flags, u32 tx_flags,
621 struct ieee80211_channel *channel)
622 {
623 struct sk_buff *skb;
624
625 skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
626 ssid, ssid_len,
627 ie, ie_len, flags);
628
629 if (skb) {
630 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
631 struct ieee80211_hdr *hdr = (void *)skb->data;
632 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
633 u16 sn = get_random_u16();
634
635 info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
636 hdr->seq_ctrl =
637 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
638 }
639 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
640 IEEE80211_SKB_CB(skb)->control.flags |= IEEE80211_TX_CTRL_DONT_USE_RATE_MASK;
641 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
642 }
643 }
644
ieee80211_scan_state_send_probe(struct ieee80211_local * local,unsigned long * next_delay)645 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
646 unsigned long *next_delay)
647 {
648 int i;
649 struct ieee80211_sub_if_data *sdata;
650 struct cfg80211_scan_request *scan_req;
651 enum nl80211_band band = local->hw.conf.chandef.chan->band;
652 u32 flags = 0, tx_flags;
653
654 scan_req = rcu_dereference_protected(local->scan_req,
655 lockdep_is_held(&local->mtx));
656
657 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
658 if (scan_req->no_cck)
659 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
660 if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
661 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
662 if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
663 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
664
665 sdata = rcu_dereference_protected(local->scan_sdata,
666 lockdep_is_held(&local->mtx));
667
668 for (i = 0; i < scan_req->n_ssids; i++)
669 ieee80211_send_scan_probe_req(
670 sdata, local->scan_addr, scan_req->bssid,
671 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
672 scan_req->ie, scan_req->ie_len,
673 scan_req->rates[band], flags,
674 tx_flags, local->hw.conf.chandef.chan);
675
676 /*
677 * After sending probe requests, wait for probe responses
678 * on the channel.
679 */
680 *next_delay = IEEE80211_CHANNEL_TIME;
681 local->next_scan_state = SCAN_DECISION;
682 }
683
__ieee80211_start_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)684 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
685 struct cfg80211_scan_request *req)
686 {
687 struct ieee80211_local *local = sdata->local;
688 bool hw_scan = local->ops->hw_scan;
689 int rc;
690
691 lockdep_assert_held(&local->mtx);
692
693 if (local->scan_req)
694 return -EBUSY;
695
696 if (!__ieee80211_can_leave_ch(sdata))
697 return -EBUSY;
698
699 if (!ieee80211_can_scan(local, sdata)) {
700 /* wait for the work to finish/time out */
701 rcu_assign_pointer(local->scan_req, req);
702 rcu_assign_pointer(local->scan_sdata, sdata);
703 return 0;
704 }
705
706 again:
707 if (hw_scan) {
708 u8 *ies;
709
710 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
711
712 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
713 int i, n_bands = 0;
714 u8 bands_counted = 0;
715
716 for (i = 0; i < req->n_channels; i++) {
717 if (bands_counted & BIT(req->channels[i]->band))
718 continue;
719 bands_counted |= BIT(req->channels[i]->band);
720 n_bands++;
721 }
722
723 local->hw_scan_ies_bufsize *= n_bands;
724 }
725
726 local->hw_scan_req = kmalloc(struct_size(local->hw_scan_req,
727 req.channels,
728 req->n_channels) +
729 local->hw_scan_ies_bufsize,
730 GFP_KERNEL);
731 if (!local->hw_scan_req)
732 return -ENOMEM;
733
734 local->hw_scan_req->req.ssids = req->ssids;
735 local->hw_scan_req->req.n_ssids = req->n_ssids;
736 /* None of the channels are actually set
737 * up but let UBSAN know the boundaries.
738 */
739 local->hw_scan_req->req.n_channels = req->n_channels;
740
741 ies = (u8 *)local->hw_scan_req +
742 sizeof(*local->hw_scan_req) +
743 req->n_channels * sizeof(req->channels[0]);
744 local->hw_scan_req->req.ie = ies;
745 local->hw_scan_req->req.flags = req->flags;
746 eth_broadcast_addr(local->hw_scan_req->req.bssid);
747 local->hw_scan_req->req.duration = req->duration;
748 local->hw_scan_req->req.duration_mandatory =
749 req->duration_mandatory;
750
751 local->hw_scan_band = 0;
752 local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
753 local->hw_scan_req->req.scan_6ghz_params =
754 req->scan_6ghz_params;
755 local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
756
757 /*
758 * After allocating local->hw_scan_req, we must
759 * go through until ieee80211_prep_hw_scan(), so
760 * anything that might be changed here and leave
761 * this function early must not go after this
762 * allocation.
763 */
764 }
765
766 rcu_assign_pointer(local->scan_req, req);
767 rcu_assign_pointer(local->scan_sdata, sdata);
768
769 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
770 get_random_mask_addr(local->scan_addr,
771 req->mac_addr,
772 req->mac_addr_mask);
773 else
774 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
775
776 if (hw_scan) {
777 __set_bit(SCAN_HW_SCANNING, &local->scanning);
778 } else if ((req->n_channels == 1) &&
779 (req->channels[0] == local->_oper_chandef.chan)) {
780 /*
781 * If we are scanning only on the operating channel
782 * then we do not need to stop normal activities
783 */
784 unsigned long next_delay;
785
786 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
787
788 ieee80211_recalc_idle(local);
789
790 /* Notify driver scan is starting, keep order of operations
791 * same as normal software scan, in case that matters. */
792 drv_sw_scan_start(local, sdata, local->scan_addr);
793
794 ieee80211_configure_filter(local); /* accept probe-responses */
795
796 /* We need to ensure power level is at max for scanning. */
797 ieee80211_hw_config(local, 0);
798
799 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
800 IEEE80211_CHAN_RADAR)) ||
801 !req->n_ssids) {
802 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
803 if (req->n_ssids)
804 set_bit(SCAN_BEACON_WAIT, &local->scanning);
805 } else {
806 ieee80211_scan_state_send_probe(local, &next_delay);
807 next_delay = IEEE80211_CHANNEL_TIME;
808 }
809
810 /* Now, just wait a bit and we are all done! */
811 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
812 next_delay);
813 return 0;
814 } else {
815 /* Do normal software scan */
816 __set_bit(SCAN_SW_SCANNING, &local->scanning);
817 }
818
819 ieee80211_recalc_idle(local);
820
821 if (hw_scan) {
822 WARN_ON(!ieee80211_prep_hw_scan(sdata));
823 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
824 } else {
825 rc = ieee80211_start_sw_scan(local, sdata);
826 }
827
828 if (rc) {
829 kfree(local->hw_scan_req);
830 local->hw_scan_req = NULL;
831 local->scanning = 0;
832
833 ieee80211_recalc_idle(local);
834
835 local->scan_req = NULL;
836 RCU_INIT_POINTER(local->scan_sdata, NULL);
837 }
838
839 if (hw_scan && rc == 1) {
840 /*
841 * we can't fall back to software for P2P-GO
842 * as it must update NoA etc.
843 */
844 if (ieee80211_vif_type_p2p(&sdata->vif) ==
845 NL80211_IFTYPE_P2P_GO)
846 return -EOPNOTSUPP;
847 hw_scan = false;
848 goto again;
849 }
850
851 return rc;
852 }
853
854 static unsigned long
ieee80211_scan_get_channel_time(struct ieee80211_channel * chan)855 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
856 {
857 /*
858 * TODO: channel switching also consumes quite some time,
859 * add that delay as well to get a better estimation
860 */
861 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
862 return IEEE80211_PASSIVE_CHANNEL_TIME;
863 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
864 }
865
ieee80211_scan_state_decision(struct ieee80211_local * local,unsigned long * next_delay)866 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
867 unsigned long *next_delay)
868 {
869 bool associated = false;
870 bool tx_empty = true;
871 bool bad_latency;
872 struct ieee80211_sub_if_data *sdata;
873 struct ieee80211_channel *next_chan;
874 enum mac80211_scan_state next_scan_state;
875 struct cfg80211_scan_request *scan_req;
876
877 /*
878 * check if at least one STA interface is associated,
879 * check if at least one STA interface has pending tx frames
880 * and grab the lowest used beacon interval
881 */
882 mutex_lock(&local->iflist_mtx);
883 list_for_each_entry(sdata, &local->interfaces, list) {
884 if (!ieee80211_sdata_running(sdata))
885 continue;
886
887 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
888 if (sdata->u.mgd.associated) {
889 associated = true;
890
891 if (!qdisc_all_tx_empty(sdata->dev)) {
892 tx_empty = false;
893 break;
894 }
895 }
896 }
897 }
898 mutex_unlock(&local->iflist_mtx);
899
900 scan_req = rcu_dereference_protected(local->scan_req,
901 lockdep_is_held(&local->mtx));
902
903 next_chan = scan_req->channels[local->scan_channel_idx];
904
905 /*
906 * we're currently scanning a different channel, let's
907 * see if we can scan another channel without interfering
908 * with the current traffic situation.
909 *
910 * Keep good latency, do not stay off-channel more than 125 ms.
911 */
912
913 bad_latency = time_after(jiffies +
914 ieee80211_scan_get_channel_time(next_chan),
915 local->leave_oper_channel_time + HZ / 8);
916
917 if (associated && !tx_empty) {
918 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
919 next_scan_state = SCAN_ABORT;
920 else
921 next_scan_state = SCAN_SUSPEND;
922 } else if (associated && bad_latency) {
923 next_scan_state = SCAN_SUSPEND;
924 } else {
925 next_scan_state = SCAN_SET_CHANNEL;
926 }
927
928 local->next_scan_state = next_scan_state;
929
930 *next_delay = 0;
931 }
932
ieee80211_scan_state_set_channel(struct ieee80211_local * local,unsigned long * next_delay)933 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
934 unsigned long *next_delay)
935 {
936 int skip;
937 struct ieee80211_channel *chan;
938 enum nl80211_bss_scan_width oper_scan_width;
939 struct cfg80211_scan_request *scan_req;
940
941 scan_req = rcu_dereference_protected(local->scan_req,
942 lockdep_is_held(&local->mtx));
943
944 skip = 0;
945 chan = scan_req->channels[local->scan_channel_idx];
946
947 local->scan_chandef.chan = chan;
948 local->scan_chandef.center_freq1 = chan->center_freq;
949 local->scan_chandef.freq1_offset = chan->freq_offset;
950 local->scan_chandef.center_freq2 = 0;
951
952 /* For scanning on the S1G band, ignore scan_width (which is constant
953 * across all channels) for now since channel width is specific to each
954 * channel. Detect the required channel width here and likely revisit
955 * later. Maybe scan_width could be used to build the channel scan list?
956 */
957 if (chan->band == NL80211_BAND_S1GHZ) {
958 local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
959 goto set_channel;
960 }
961
962 switch (scan_req->scan_width) {
963 case NL80211_BSS_CHAN_WIDTH_5:
964 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
965 break;
966 case NL80211_BSS_CHAN_WIDTH_10:
967 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
968 break;
969 default:
970 case NL80211_BSS_CHAN_WIDTH_20:
971 /* If scanning on oper channel, use whatever channel-type
972 * is currently in use.
973 */
974 oper_scan_width = cfg80211_chandef_to_scan_width(
975 &local->_oper_chandef);
976 if (chan == local->_oper_chandef.chan &&
977 oper_scan_width == scan_req->scan_width)
978 local->scan_chandef = local->_oper_chandef;
979 else
980 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
981 break;
982 case NL80211_BSS_CHAN_WIDTH_1:
983 case NL80211_BSS_CHAN_WIDTH_2:
984 /* shouldn't get here, S1G handled above */
985 WARN_ON(1);
986 break;
987 }
988
989 set_channel:
990 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
991 skip = 1;
992
993 /* advance state machine to next channel/band */
994 local->scan_channel_idx++;
995
996 if (skip) {
997 /* if we skip this channel return to the decision state */
998 local->next_scan_state = SCAN_DECISION;
999 return;
1000 }
1001
1002 /*
1003 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
1004 * (which unfortunately doesn't say _why_ step a) is done,
1005 * but it waits for the probe delay or until a frame is
1006 * received - and the received frame would update the NAV).
1007 * For now, we do not support waiting until a frame is
1008 * received.
1009 *
1010 * In any case, it is not necessary for a passive scan.
1011 */
1012 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
1013 !scan_req->n_ssids) {
1014 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
1015 local->next_scan_state = SCAN_DECISION;
1016 if (scan_req->n_ssids)
1017 set_bit(SCAN_BEACON_WAIT, &local->scanning);
1018 return;
1019 }
1020
1021 /* active scan, send probes */
1022 *next_delay = IEEE80211_PROBE_DELAY;
1023 local->next_scan_state = SCAN_SEND_PROBE;
1024 }
1025
ieee80211_scan_state_suspend(struct ieee80211_local * local,unsigned long * next_delay)1026 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1027 unsigned long *next_delay)
1028 {
1029 /* switch back to the operating channel */
1030 local->scan_chandef.chan = NULL;
1031 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
1032
1033 /* disable PS */
1034 ieee80211_offchannel_return(local);
1035
1036 *next_delay = HZ / 5;
1037 /* afterwards, resume scan & go to next channel */
1038 local->next_scan_state = SCAN_RESUME;
1039 }
1040
ieee80211_scan_state_resume(struct ieee80211_local * local,unsigned long * next_delay)1041 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1042 unsigned long *next_delay)
1043 {
1044 ieee80211_offchannel_stop_vifs(local);
1045
1046 if (local->ops->flush) {
1047 ieee80211_flush_queues(local, NULL, false);
1048 *next_delay = 0;
1049 } else
1050 *next_delay = HZ / 10;
1051
1052 /* remember when we left the operating channel */
1053 local->leave_oper_channel_time = jiffies;
1054
1055 /* advance to the next channel to be scanned */
1056 local->next_scan_state = SCAN_SET_CHANNEL;
1057 }
1058
ieee80211_scan_work(struct wiphy * wiphy,struct wiphy_work * work)1059 void ieee80211_scan_work(struct wiphy *wiphy, struct wiphy_work *work)
1060 {
1061 struct ieee80211_local *local =
1062 container_of(work, struct ieee80211_local, scan_work.work);
1063 struct ieee80211_sub_if_data *sdata;
1064 struct cfg80211_scan_request *scan_req;
1065 unsigned long next_delay = 0;
1066 bool aborted;
1067
1068 mutex_lock(&local->mtx);
1069
1070 if (!ieee80211_can_run_worker(local)) {
1071 aborted = true;
1072 goto out_complete;
1073 }
1074
1075 sdata = rcu_dereference_protected(local->scan_sdata,
1076 lockdep_is_held(&local->mtx));
1077 scan_req = rcu_dereference_protected(local->scan_req,
1078 lockdep_is_held(&local->mtx));
1079
1080 /* When scanning on-channel, the first-callback means completed. */
1081 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1082 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1083 goto out_complete;
1084 }
1085
1086 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1087 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1088 goto out_complete;
1089 }
1090
1091 if (!sdata || !scan_req)
1092 goto out;
1093
1094 if (!local->scanning) {
1095 int rc;
1096
1097 RCU_INIT_POINTER(local->scan_req, NULL);
1098 RCU_INIT_POINTER(local->scan_sdata, NULL);
1099
1100 rc = __ieee80211_start_scan(sdata, scan_req);
1101 if (rc) {
1102 /* need to complete scan in cfg80211 */
1103 rcu_assign_pointer(local->scan_req, scan_req);
1104 aborted = true;
1105 goto out_complete;
1106 } else
1107 goto out;
1108 }
1109
1110 clear_bit(SCAN_BEACON_WAIT, &local->scanning);
1111
1112 /*
1113 * as long as no delay is required advance immediately
1114 * without scheduling a new work
1115 */
1116 do {
1117 if (!ieee80211_sdata_running(sdata)) {
1118 aborted = true;
1119 goto out_complete;
1120 }
1121
1122 if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) &&
1123 local->next_scan_state == SCAN_DECISION)
1124 local->next_scan_state = SCAN_SEND_PROBE;
1125
1126 switch (local->next_scan_state) {
1127 case SCAN_DECISION:
1128 /* if no more bands/channels left, complete scan */
1129 if (local->scan_channel_idx >= scan_req->n_channels) {
1130 aborted = false;
1131 goto out_complete;
1132 }
1133 ieee80211_scan_state_decision(local, &next_delay);
1134 break;
1135 case SCAN_SET_CHANNEL:
1136 ieee80211_scan_state_set_channel(local, &next_delay);
1137 break;
1138 case SCAN_SEND_PROBE:
1139 ieee80211_scan_state_send_probe(local, &next_delay);
1140 break;
1141 case SCAN_SUSPEND:
1142 ieee80211_scan_state_suspend(local, &next_delay);
1143 break;
1144 case SCAN_RESUME:
1145 ieee80211_scan_state_resume(local, &next_delay);
1146 break;
1147 case SCAN_ABORT:
1148 aborted = true;
1149 goto out_complete;
1150 }
1151 } while (next_delay == 0);
1152
1153 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
1154 next_delay);
1155 goto out;
1156
1157 out_complete:
1158 __ieee80211_scan_completed(&local->hw, aborted);
1159 out:
1160 mutex_unlock(&local->mtx);
1161 }
1162
ieee80211_request_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)1163 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1164 struct cfg80211_scan_request *req)
1165 {
1166 int res;
1167
1168 mutex_lock(&sdata->local->mtx);
1169 res = __ieee80211_start_scan(sdata, req);
1170 mutex_unlock(&sdata->local->mtx);
1171
1172 return res;
1173 }
1174
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)1175 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1176 const u8 *ssid, u8 ssid_len,
1177 struct ieee80211_channel **channels,
1178 unsigned int n_channels,
1179 enum nl80211_bss_scan_width scan_width)
1180 {
1181 struct ieee80211_local *local = sdata->local;
1182 int ret = -EBUSY, i, n_ch = 0;
1183 enum nl80211_band band;
1184
1185 mutex_lock(&local->mtx);
1186
1187 /* busy scanning */
1188 if (local->scan_req)
1189 goto unlock;
1190
1191 /* fill internal scan request */
1192 if (!channels) {
1193 int max_n;
1194
1195 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1196 if (!local->hw.wiphy->bands[band] ||
1197 band == NL80211_BAND_6GHZ)
1198 continue;
1199
1200 max_n = local->hw.wiphy->bands[band]->n_channels;
1201 for (i = 0; i < max_n; i++) {
1202 struct ieee80211_channel *tmp_ch =
1203 &local->hw.wiphy->bands[band]->channels[i];
1204
1205 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1206 IEEE80211_CHAN_DISABLED))
1207 continue;
1208
1209 local->int_scan_req->channels[n_ch] = tmp_ch;
1210 n_ch++;
1211 }
1212 }
1213
1214 if (WARN_ON_ONCE(n_ch == 0))
1215 goto unlock;
1216
1217 local->int_scan_req->n_channels = n_ch;
1218 } else {
1219 for (i = 0; i < n_channels; i++) {
1220 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1221 IEEE80211_CHAN_DISABLED))
1222 continue;
1223
1224 local->int_scan_req->channels[n_ch] = channels[i];
1225 n_ch++;
1226 }
1227
1228 if (WARN_ON_ONCE(n_ch == 0))
1229 goto unlock;
1230
1231 local->int_scan_req->n_channels = n_ch;
1232 }
1233
1234 local->int_scan_req->ssids = &local->scan_ssid;
1235 local->int_scan_req->n_ssids = 1;
1236 local->int_scan_req->scan_width = scan_width;
1237 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1238 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1239
1240 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1241 unlock:
1242 mutex_unlock(&local->mtx);
1243 return ret;
1244 }
1245
ieee80211_scan_cancel(struct ieee80211_local * local)1246 void ieee80211_scan_cancel(struct ieee80211_local *local)
1247 {
1248 /* ensure a new scan cannot be queued */
1249 lockdep_assert_wiphy(local->hw.wiphy);
1250
1251 /*
1252 * We are canceling software scan, or deferred scan that was not
1253 * yet really started (see __ieee80211_start_scan ).
1254 *
1255 * Regarding hardware scan:
1256 * - we can not call __ieee80211_scan_completed() as when
1257 * SCAN_HW_SCANNING bit is set this function change
1258 * local->hw_scan_req to operate on 5G band, what race with
1259 * driver which can use local->hw_scan_req
1260 *
1261 * - we can not cancel scan_work since driver can schedule it
1262 * by ieee80211_scan_completed(..., true) to finish scan
1263 *
1264 * Hence we only call the cancel_hw_scan() callback, but the low-level
1265 * driver is still responsible for calling ieee80211_scan_completed()
1266 * after the scan was completed/aborted.
1267 */
1268
1269 mutex_lock(&local->mtx);
1270 if (!local->scan_req)
1271 goto out;
1272
1273 /*
1274 * We have a scan running and the driver already reported completion,
1275 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1276 * cancelled.
1277 */
1278 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1279 test_bit(SCAN_COMPLETED, &local->scanning)) {
1280 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1281 goto out;
1282 }
1283
1284 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1285 /*
1286 * Make sure that __ieee80211_scan_completed doesn't trigger a
1287 * scan on another band.
1288 */
1289 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1290 if (local->ops->cancel_hw_scan)
1291 drv_cancel_hw_scan(local,
1292 rcu_dereference_protected(local->scan_sdata,
1293 lockdep_is_held(&local->mtx)));
1294 goto out;
1295 }
1296
1297 wiphy_delayed_work_cancel(local->hw.wiphy, &local->scan_work);
1298 /* and clean up */
1299 memset(&local->scan_info, 0, sizeof(local->scan_info));
1300 __ieee80211_scan_completed(&local->hw, true);
1301 out:
1302 mutex_unlock(&local->mtx);
1303 }
1304
__ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1305 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1306 struct cfg80211_sched_scan_request *req)
1307 {
1308 struct ieee80211_local *local = sdata->local;
1309 struct ieee80211_scan_ies sched_scan_ies = {};
1310 struct cfg80211_chan_def chandef;
1311 int ret, i, iebufsz, num_bands = 0;
1312 u32 rate_masks[NUM_NL80211_BANDS] = {};
1313 u8 bands_used = 0;
1314 u8 *ie;
1315 u32 flags = 0;
1316
1317 iebufsz = local->scan_ies_len + req->ie_len;
1318
1319 lockdep_assert_held(&local->mtx);
1320
1321 if (!local->ops->sched_scan_start)
1322 return -ENOTSUPP;
1323
1324 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1325 if (local->hw.wiphy->bands[i]) {
1326 bands_used |= BIT(i);
1327 rate_masks[i] = (u32) -1;
1328 num_bands++;
1329 }
1330 }
1331
1332 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1333 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1334
1335 ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1336 if (!ie) {
1337 ret = -ENOMEM;
1338 goto out;
1339 }
1340
1341 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1342
1343 ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1344 &sched_scan_ies, req->ie,
1345 req->ie_len, bands_used, rate_masks, &chandef,
1346 flags);
1347
1348 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1349 if (ret == 0) {
1350 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1351 rcu_assign_pointer(local->sched_scan_req, req);
1352 }
1353
1354 kfree(ie);
1355
1356 out:
1357 if (ret) {
1358 /* Clean in case of failure after HW restart or upon resume. */
1359 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1360 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1361 }
1362
1363 return ret;
1364 }
1365
ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1366 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1367 struct cfg80211_sched_scan_request *req)
1368 {
1369 struct ieee80211_local *local = sdata->local;
1370 int ret;
1371
1372 mutex_lock(&local->mtx);
1373
1374 if (rcu_access_pointer(local->sched_scan_sdata)) {
1375 mutex_unlock(&local->mtx);
1376 return -EBUSY;
1377 }
1378
1379 ret = __ieee80211_request_sched_scan_start(sdata, req);
1380
1381 mutex_unlock(&local->mtx);
1382 return ret;
1383 }
1384
ieee80211_request_sched_scan_stop(struct ieee80211_local * local)1385 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1386 {
1387 struct ieee80211_sub_if_data *sched_scan_sdata;
1388 int ret = -ENOENT;
1389
1390 mutex_lock(&local->mtx);
1391
1392 if (!local->ops->sched_scan_stop) {
1393 ret = -ENOTSUPP;
1394 goto out;
1395 }
1396
1397 /* We don't want to restart sched scan anymore. */
1398 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1399
1400 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1401 lockdep_is_held(&local->mtx));
1402 if (sched_scan_sdata) {
1403 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1404 if (!ret)
1405 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1406 }
1407 out:
1408 mutex_unlock(&local->mtx);
1409
1410 return ret;
1411 }
1412
ieee80211_sched_scan_results(struct ieee80211_hw * hw)1413 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1414 {
1415 struct ieee80211_local *local = hw_to_local(hw);
1416
1417 trace_api_sched_scan_results(local);
1418
1419 cfg80211_sched_scan_results(hw->wiphy, 0);
1420 }
1421 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1422
ieee80211_sched_scan_end(struct ieee80211_local * local)1423 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1424 {
1425 mutex_lock(&local->mtx);
1426
1427 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1428 mutex_unlock(&local->mtx);
1429 return;
1430 }
1431
1432 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1433
1434 /* If sched scan was aborted by the driver. */
1435 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1436
1437 mutex_unlock(&local->mtx);
1438
1439 cfg80211_sched_scan_stopped_locked(local->hw.wiphy, 0);
1440 }
1441
ieee80211_sched_scan_stopped_work(struct wiphy * wiphy,struct wiphy_work * work)1442 void ieee80211_sched_scan_stopped_work(struct wiphy *wiphy,
1443 struct wiphy_work *work)
1444 {
1445 struct ieee80211_local *local =
1446 container_of(work, struct ieee80211_local,
1447 sched_scan_stopped_work);
1448
1449 ieee80211_sched_scan_end(local);
1450 }
1451
ieee80211_sched_scan_stopped(struct ieee80211_hw * hw)1452 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1453 {
1454 struct ieee80211_local *local = hw_to_local(hw);
1455
1456 trace_api_sched_scan_stopped(local);
1457
1458 /*
1459 * this shouldn't really happen, so for simplicity
1460 * simply ignore it, and let mac80211 reconfigure
1461 * the sched scan later on.
1462 */
1463 if (local->in_reconfig)
1464 return;
1465
1466 wiphy_work_queue(hw->wiphy, &local->sched_scan_stopped_work);
1467 }
1468 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
1469