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) 2018-2020 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 static void
ieee80211_update_bss_from_elems(struct ieee80211_local * local,struct ieee80211_bss * bss,struct ieee802_11_elems * elems,struct ieee80211_rx_status * rx_status,bool beacon)59 ieee80211_update_bss_from_elems(struct ieee80211_local *local,
60 struct ieee80211_bss *bss,
61 struct ieee802_11_elems *elems,
62 struct ieee80211_rx_status *rx_status,
63 bool beacon)
64 {
65 int clen, srlen;
66
67 if (beacon)
68 bss->device_ts_beacon = rx_status->device_timestamp;
69 else
70 bss->device_ts_presp = rx_status->device_timestamp;
71
72 if (elems->parse_error) {
73 if (beacon)
74 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
75 else
76 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
77 } else {
78 if (beacon)
79 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
80 else
81 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
82 }
83
84 /* save the ERP value so that it is available at association time */
85 if (elems->erp_info && (!elems->parse_error ||
86 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
87 bss->erp_value = elems->erp_info[0];
88 bss->has_erp_value = true;
89 if (!elems->parse_error)
90 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
91 }
92
93 /* replace old supported rates if we get new values */
94 if (!elems->parse_error ||
95 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
96 srlen = 0;
97 if (elems->supp_rates) {
98 clen = IEEE80211_MAX_SUPP_RATES;
99 if (clen > elems->supp_rates_len)
100 clen = elems->supp_rates_len;
101 memcpy(bss->supp_rates, elems->supp_rates, clen);
102 srlen += clen;
103 }
104 if (elems->ext_supp_rates) {
105 clen = IEEE80211_MAX_SUPP_RATES - srlen;
106 if (clen > elems->ext_supp_rates_len)
107 clen = elems->ext_supp_rates_len;
108 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
109 clen);
110 srlen += clen;
111 }
112 if (srlen) {
113 bss->supp_rates_len = srlen;
114 if (!elems->parse_error)
115 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
116 }
117 }
118
119 if (!elems->parse_error ||
120 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
121 bss->wmm_used = elems->wmm_param || elems->wmm_info;
122 bss->uapsd_supported = is_uapsd_supported(elems);
123 if (!elems->parse_error)
124 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
125 }
126
127 if (beacon) {
128 struct ieee80211_supported_band *sband =
129 local->hw.wiphy->bands[rx_status->band];
130 if (!(rx_status->encoding == RX_ENC_HT) &&
131 !(rx_status->encoding == RX_ENC_VHT))
132 bss->beacon_rate =
133 &sband->bitrates[rx_status->rate_idx];
134 }
135
136 if (elems->vht_cap_elem)
137 bss->vht_cap_info =
138 le32_to_cpu(elems->vht_cap_elem->vht_cap_info);
139 else
140 bss->vht_cap_info = 0;
141 }
142
143 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)144 ieee80211_bss_info_update(struct ieee80211_local *local,
145 struct ieee80211_rx_status *rx_status,
146 struct ieee80211_mgmt *mgmt, size_t len,
147 struct ieee80211_channel *channel)
148 {
149 bool beacon = ieee80211_is_beacon(mgmt->frame_control) ||
150 ieee80211_is_s1g_beacon(mgmt->frame_control);
151 struct cfg80211_bss *cbss, *non_tx_cbss;
152 struct ieee80211_bss *bss, *non_tx_bss;
153 struct cfg80211_inform_bss bss_meta = {
154 .boottime_ns = rx_status->boottime_ns,
155 };
156 bool signal_valid;
157 struct ieee80211_sub_if_data *scan_sdata;
158 struct ieee802_11_elems elems;
159 size_t baselen;
160 u8 *elements;
161
162 if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
163 bss_meta.signal = 0; /* invalid signal indication */
164 else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
165 bss_meta.signal = rx_status->signal * 100;
166 else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
167 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
168
169 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
170 if (rx_status->bw == RATE_INFO_BW_5)
171 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
172 else if (rx_status->bw == RATE_INFO_BW_10)
173 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
174
175 bss_meta.chan = channel;
176
177 rcu_read_lock();
178 scan_sdata = rcu_dereference(local->scan_sdata);
179 if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
180 scan_sdata->vif.bss_conf.assoc &&
181 ieee80211_have_rx_timestamp(rx_status)) {
182 bss_meta.parent_tsf =
183 ieee80211_calculate_rx_timestamp(local, rx_status,
184 len + FCS_LEN, 24);
185 ether_addr_copy(bss_meta.parent_bssid,
186 scan_sdata->vif.bss_conf.bssid);
187 }
188 rcu_read_unlock();
189
190 cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
191 mgmt, len, GFP_ATOMIC);
192 if (!cbss)
193 return NULL;
194
195 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
196 elements = mgmt->u.probe_resp.variable;
197 baselen = offsetof(struct ieee80211_mgmt,
198 u.probe_resp.variable);
199 } else if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
200 struct ieee80211_ext *ext = (void *) mgmt;
201
202 baselen = offsetof(struct ieee80211_ext, u.s1g_beacon.variable);
203 elements = ext->u.s1g_beacon.variable;
204 } else {
205 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
206 elements = mgmt->u.beacon.variable;
207 }
208
209 if (baselen > len)
210 return NULL;
211
212 ieee802_11_parse_elems(elements, len - baselen, false, &elems,
213 mgmt->bssid, cbss->bssid);
214
215 /* In case the signal is invalid update the status */
216 signal_valid = channel == cbss->channel;
217 if (!signal_valid)
218 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
219
220 bss = (void *)cbss->priv;
221 ieee80211_update_bss_from_elems(local, bss, &elems, rx_status, beacon);
222
223 list_for_each_entry(non_tx_cbss, &cbss->nontrans_list, nontrans_list) {
224 non_tx_bss = (void *)non_tx_cbss->priv;
225
226 ieee80211_update_bss_from_elems(local, non_tx_bss, &elems,
227 rx_status, beacon);
228 }
229
230 return bss;
231 }
232
ieee80211_scan_accept_presp(struct ieee80211_sub_if_data * sdata,u32 scan_flags,const u8 * da)233 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
234 u32 scan_flags, const u8 *da)
235 {
236 if (!sdata)
237 return false;
238 /* accept broadcast for OCE */
239 if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
240 is_broadcast_ether_addr(da))
241 return true;
242 if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
243 return true;
244 return ether_addr_equal(da, sdata->vif.addr);
245 }
246
ieee80211_scan_rx(struct ieee80211_local * local,struct sk_buff * skb)247 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
248 {
249 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
250 struct ieee80211_sub_if_data *sdata1, *sdata2;
251 struct ieee80211_mgmt *mgmt = (void *)skb->data;
252 struct ieee80211_bss *bss;
253 struct ieee80211_channel *channel;
254
255 if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
256 if (skb->len < 15)
257 return;
258 } else if (skb->len < 24 ||
259 (!ieee80211_is_probe_resp(mgmt->frame_control) &&
260 !ieee80211_is_beacon(mgmt->frame_control)))
261 return;
262
263 sdata1 = rcu_dereference(local->scan_sdata);
264 sdata2 = rcu_dereference(local->sched_scan_sdata);
265
266 if (likely(!sdata1 && !sdata2))
267 return;
268
269 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
270 struct cfg80211_scan_request *scan_req;
271 struct cfg80211_sched_scan_request *sched_scan_req;
272 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
273
274 scan_req = rcu_dereference(local->scan_req);
275 sched_scan_req = rcu_dereference(local->sched_scan_req);
276
277 if (scan_req)
278 scan_req_flags = scan_req->flags;
279
280 if (sched_scan_req)
281 sched_scan_req_flags = sched_scan_req->flags;
282
283 /* ignore ProbeResp to foreign address or non-bcast (OCE)
284 * unless scanning with randomised address
285 */
286 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
287 mgmt->da) &&
288 !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
289 mgmt->da))
290 return;
291 }
292
293 channel = ieee80211_get_channel_khz(local->hw.wiphy,
294 ieee80211_rx_status_to_khz(rx_status));
295
296 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
297 return;
298
299 bss = ieee80211_bss_info_update(local, rx_status,
300 mgmt, skb->len,
301 channel);
302 if (bss)
303 ieee80211_rx_bss_put(local, bss);
304 }
305
306 static void
ieee80211_prepare_scan_chandef(struct cfg80211_chan_def * chandef,enum nl80211_bss_scan_width scan_width)307 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
308 enum nl80211_bss_scan_width scan_width)
309 {
310 memset(chandef, 0, sizeof(*chandef));
311 switch (scan_width) {
312 case NL80211_BSS_CHAN_WIDTH_5:
313 chandef->width = NL80211_CHAN_WIDTH_5;
314 break;
315 case NL80211_BSS_CHAN_WIDTH_10:
316 chandef->width = NL80211_CHAN_WIDTH_10;
317 break;
318 default:
319 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
320 break;
321 }
322 }
323
324 /* return false if no more work */
ieee80211_prep_hw_scan(struct ieee80211_sub_if_data * sdata)325 static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
326 {
327 struct ieee80211_local *local = sdata->local;
328 struct cfg80211_scan_request *req;
329 struct cfg80211_chan_def chandef;
330 u8 bands_used = 0;
331 int i, ielen, n_chans;
332 u32 flags = 0;
333
334 req = rcu_dereference_protected(local->scan_req,
335 lockdep_is_held(&local->mtx));
336
337 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
338 return false;
339
340 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
341 for (i = 0; i < req->n_channels; i++) {
342 local->hw_scan_req->req.channels[i] = req->channels[i];
343 bands_used |= BIT(req->channels[i]->band);
344 }
345
346 n_chans = req->n_channels;
347 } else {
348 do {
349 if (local->hw_scan_band == NUM_NL80211_BANDS)
350 return false;
351
352 n_chans = 0;
353
354 for (i = 0; i < req->n_channels; i++) {
355 if (req->channels[i]->band !=
356 local->hw_scan_band)
357 continue;
358 local->hw_scan_req->req.channels[n_chans] =
359 req->channels[i];
360 n_chans++;
361 bands_used |= BIT(req->channels[i]->band);
362 }
363
364 local->hw_scan_band++;
365 } while (!n_chans);
366 }
367
368 local->hw_scan_req->req.n_channels = n_chans;
369 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
370
371 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
372 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
373
374 ielen = ieee80211_build_preq_ies(sdata,
375 (u8 *)local->hw_scan_req->req.ie,
376 local->hw_scan_ies_bufsize,
377 &local->hw_scan_req->ies,
378 req->ie, req->ie_len,
379 bands_used, req->rates, &chandef,
380 flags);
381 local->hw_scan_req->req.ie_len = ielen;
382 local->hw_scan_req->req.no_cck = req->no_cck;
383 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
384 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
385 req->mac_addr_mask);
386 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
387
388 return true;
389 }
390
__ieee80211_scan_completed(struct ieee80211_hw * hw,bool aborted)391 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
392 {
393 struct ieee80211_local *local = hw_to_local(hw);
394 bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
395 bool was_scanning = local->scanning;
396 struct cfg80211_scan_request *scan_req;
397 struct ieee80211_sub_if_data *scan_sdata;
398 struct ieee80211_sub_if_data *sdata;
399
400 lockdep_assert_held(&local->mtx);
401
402 /*
403 * It's ok to abort a not-yet-running scan (that
404 * we have one at all will be verified by checking
405 * local->scan_req next), but not to complete it
406 * successfully.
407 */
408 if (WARN_ON(!local->scanning && !aborted))
409 aborted = true;
410
411 if (WARN_ON(!local->scan_req))
412 return;
413
414 scan_sdata = rcu_dereference_protected(local->scan_sdata,
415 lockdep_is_held(&local->mtx));
416
417 if (hw_scan && !aborted &&
418 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
419 ieee80211_prep_hw_scan(scan_sdata)) {
420 int rc;
421
422 rc = drv_hw_scan(local,
423 rcu_dereference_protected(local->scan_sdata,
424 lockdep_is_held(&local->mtx)),
425 local->hw_scan_req);
426
427 if (rc == 0)
428 return;
429
430 /* HW scan failed and is going to be reported as aborted,
431 * so clear old scan info.
432 */
433 memset(&local->scan_info, 0, sizeof(local->scan_info));
434 aborted = true;
435 }
436
437 kfree(local->hw_scan_req);
438 local->hw_scan_req = NULL;
439
440 scan_req = rcu_dereference_protected(local->scan_req,
441 lockdep_is_held(&local->mtx));
442
443 if (scan_req != local->int_scan_req) {
444 local->scan_info.aborted = aborted;
445 cfg80211_scan_done(scan_req, &local->scan_info);
446 }
447 RCU_INIT_POINTER(local->scan_req, NULL);
448 RCU_INIT_POINTER(local->scan_sdata, NULL);
449
450 local->scanning = 0;
451 local->scan_chandef.chan = NULL;
452
453 /* Set power back to normal operating levels. */
454 ieee80211_hw_config(local, 0);
455
456 if (!hw_scan) {
457 ieee80211_configure_filter(local);
458 drv_sw_scan_complete(local, scan_sdata);
459 ieee80211_offchannel_return(local);
460 }
461
462 ieee80211_recalc_idle(local);
463
464 ieee80211_mlme_notify_scan_completed(local);
465 ieee80211_ibss_notify_scan_completed(local);
466
467 /* Requeue all the work that might have been ignored while
468 * the scan was in progress; if there was none this will
469 * just be a no-op for the particular interface.
470 */
471 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
472 if (ieee80211_sdata_running(sdata))
473 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
474 }
475
476 if (was_scanning)
477 ieee80211_start_next_roc(local);
478 }
479
ieee80211_scan_completed(struct ieee80211_hw * hw,struct cfg80211_scan_info * info)480 void ieee80211_scan_completed(struct ieee80211_hw *hw,
481 struct cfg80211_scan_info *info)
482 {
483 struct ieee80211_local *local = hw_to_local(hw);
484
485 trace_api_scan_completed(local, info->aborted);
486
487 set_bit(SCAN_COMPLETED, &local->scanning);
488 if (info->aborted)
489 set_bit(SCAN_ABORTED, &local->scanning);
490
491 memcpy(&local->scan_info, info, sizeof(*info));
492
493 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
494 }
495 EXPORT_SYMBOL(ieee80211_scan_completed);
496
ieee80211_start_sw_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)497 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
498 struct ieee80211_sub_if_data *sdata)
499 {
500 /* Software scan is not supported in multi-channel cases */
501 if (local->use_chanctx)
502 return -EOPNOTSUPP;
503
504 /*
505 * Hardware/driver doesn't support hw_scan, so use software
506 * scanning instead. First send a nullfunc frame with power save
507 * bit on so that AP will buffer the frames for us while we are not
508 * listening, then send probe requests to each channel and wait for
509 * the responses. After all channels are scanned, tune back to the
510 * original channel and send a nullfunc frame with power save bit
511 * off to trigger the AP to send us all the buffered frames.
512 *
513 * Note that while local->sw_scanning is true everything else but
514 * nullfunc frames and probe requests will be dropped in
515 * ieee80211_tx_h_check_assoc().
516 */
517 drv_sw_scan_start(local, sdata, local->scan_addr);
518
519 local->leave_oper_channel_time = jiffies;
520 local->next_scan_state = SCAN_DECISION;
521 local->scan_channel_idx = 0;
522
523 ieee80211_offchannel_stop_vifs(local);
524
525 /* ensure nullfunc is transmitted before leaving operating channel */
526 ieee80211_flush_queues(local, NULL, false);
527
528 ieee80211_configure_filter(local);
529
530 /* We need to set power level at maximum rate for scanning. */
531 ieee80211_hw_config(local, 0);
532
533 ieee80211_queue_delayed_work(&local->hw,
534 &local->scan_work, 0);
535
536 return 0;
537 }
538
__ieee80211_can_leave_ch(struct ieee80211_sub_if_data * sdata)539 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
540 {
541 struct ieee80211_local *local = sdata->local;
542 struct ieee80211_sub_if_data *sdata_iter;
543
544 if (!ieee80211_is_radar_required(local))
545 return true;
546
547 if (!regulatory_pre_cac_allowed(local->hw.wiphy))
548 return false;
549
550 mutex_lock(&local->iflist_mtx);
551 list_for_each_entry(sdata_iter, &local->interfaces, list) {
552 if (sdata_iter->wdev.cac_started) {
553 mutex_unlock(&local->iflist_mtx);
554 return false;
555 }
556 }
557 mutex_unlock(&local->iflist_mtx);
558
559 return true;
560 }
561
ieee80211_can_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)562 static bool ieee80211_can_scan(struct ieee80211_local *local,
563 struct ieee80211_sub_if_data *sdata)
564 {
565 if (!__ieee80211_can_leave_ch(sdata))
566 return false;
567
568 if (!list_empty(&local->roc_list))
569 return false;
570
571 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
572 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
573 return false;
574
575 return true;
576 }
577
ieee80211_run_deferred_scan(struct ieee80211_local * local)578 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
579 {
580 lockdep_assert_held(&local->mtx);
581
582 if (!local->scan_req || local->scanning)
583 return;
584
585 if (!ieee80211_can_scan(local,
586 rcu_dereference_protected(
587 local->scan_sdata,
588 lockdep_is_held(&local->mtx))))
589 return;
590
591 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
592 round_jiffies_relative(0));
593 }
594
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)595 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
596 const u8 *src, const u8 *dst,
597 const u8 *ssid, size_t ssid_len,
598 const u8 *ie, size_t ie_len,
599 u32 ratemask, u32 flags, u32 tx_flags,
600 struct ieee80211_channel *channel)
601 {
602 struct sk_buff *skb;
603
604 skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
605 ssid, ssid_len,
606 ie, ie_len, flags);
607
608 if (skb) {
609 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
610 struct ieee80211_hdr *hdr = (void *)skb->data;
611 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
612 u16 sn = get_random_u32();
613
614 info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
615 hdr->seq_ctrl =
616 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
617 }
618 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
619 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
620 }
621 }
622
ieee80211_scan_state_send_probe(struct ieee80211_local * local,unsigned long * next_delay)623 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
624 unsigned long *next_delay)
625 {
626 int i;
627 struct ieee80211_sub_if_data *sdata;
628 struct cfg80211_scan_request *scan_req;
629 enum nl80211_band band = local->hw.conf.chandef.chan->band;
630 u32 flags = 0, tx_flags;
631
632 scan_req = rcu_dereference_protected(local->scan_req,
633 lockdep_is_held(&local->mtx));
634
635 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
636 if (scan_req->no_cck)
637 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
638 if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
639 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
640 if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
641 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
642
643 sdata = rcu_dereference_protected(local->scan_sdata,
644 lockdep_is_held(&local->mtx));
645
646 for (i = 0; i < scan_req->n_ssids; i++)
647 ieee80211_send_scan_probe_req(
648 sdata, local->scan_addr, scan_req->bssid,
649 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
650 scan_req->ie, scan_req->ie_len,
651 scan_req->rates[band], flags,
652 tx_flags, local->hw.conf.chandef.chan);
653
654 /*
655 * After sending probe requests, wait for probe responses
656 * on the channel.
657 */
658 *next_delay = IEEE80211_CHANNEL_TIME;
659 local->next_scan_state = SCAN_DECISION;
660 }
661
__ieee80211_start_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)662 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
663 struct cfg80211_scan_request *req)
664 {
665 struct ieee80211_local *local = sdata->local;
666 bool hw_scan = local->ops->hw_scan;
667 int rc;
668
669 lockdep_assert_held(&local->mtx);
670
671 if (local->scan_req)
672 return -EBUSY;
673
674 if (!__ieee80211_can_leave_ch(sdata))
675 return -EBUSY;
676
677 if (!ieee80211_can_scan(local, sdata)) {
678 /* wait for the work to finish/time out */
679 rcu_assign_pointer(local->scan_req, req);
680 rcu_assign_pointer(local->scan_sdata, sdata);
681 return 0;
682 }
683
684 again:
685 if (hw_scan) {
686 u8 *ies;
687
688 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
689
690 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
691 int i, n_bands = 0;
692 u8 bands_counted = 0;
693
694 for (i = 0; i < req->n_channels; i++) {
695 if (bands_counted & BIT(req->channels[i]->band))
696 continue;
697 bands_counted |= BIT(req->channels[i]->band);
698 n_bands++;
699 }
700
701 local->hw_scan_ies_bufsize *= n_bands;
702 }
703
704 local->hw_scan_req = kmalloc(
705 sizeof(*local->hw_scan_req) +
706 req->n_channels * sizeof(req->channels[0]) +
707 local->hw_scan_ies_bufsize, GFP_KERNEL);
708 if (!local->hw_scan_req)
709 return -ENOMEM;
710
711 local->hw_scan_req->req.ssids = req->ssids;
712 local->hw_scan_req->req.n_ssids = req->n_ssids;
713 ies = (u8 *)local->hw_scan_req +
714 sizeof(*local->hw_scan_req) +
715 req->n_channels * sizeof(req->channels[0]);
716 local->hw_scan_req->req.ie = ies;
717 local->hw_scan_req->req.flags = req->flags;
718 eth_broadcast_addr(local->hw_scan_req->req.bssid);
719 local->hw_scan_req->req.duration = req->duration;
720 local->hw_scan_req->req.duration_mandatory =
721 req->duration_mandatory;
722
723 local->hw_scan_band = 0;
724 local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
725 local->hw_scan_req->req.scan_6ghz_params =
726 req->scan_6ghz_params;
727 local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
728
729 /*
730 * After allocating local->hw_scan_req, we must
731 * go through until ieee80211_prep_hw_scan(), so
732 * anything that might be changed here and leave
733 * this function early must not go after this
734 * allocation.
735 */
736 }
737
738 rcu_assign_pointer(local->scan_req, req);
739 rcu_assign_pointer(local->scan_sdata, sdata);
740
741 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
742 get_random_mask_addr(local->scan_addr,
743 req->mac_addr,
744 req->mac_addr_mask);
745 else
746 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
747
748 if (hw_scan) {
749 __set_bit(SCAN_HW_SCANNING, &local->scanning);
750 } else if ((req->n_channels == 1) &&
751 (req->channels[0] == local->_oper_chandef.chan)) {
752 /*
753 * If we are scanning only on the operating channel
754 * then we do not need to stop normal activities
755 */
756 unsigned long next_delay;
757
758 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
759
760 ieee80211_recalc_idle(local);
761
762 /* Notify driver scan is starting, keep order of operations
763 * same as normal software scan, in case that matters. */
764 drv_sw_scan_start(local, sdata, local->scan_addr);
765
766 ieee80211_configure_filter(local); /* accept probe-responses */
767
768 /* We need to ensure power level is at max for scanning. */
769 ieee80211_hw_config(local, 0);
770
771 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
772 IEEE80211_CHAN_RADAR)) ||
773 !req->n_ssids) {
774 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
775 } else {
776 ieee80211_scan_state_send_probe(local, &next_delay);
777 next_delay = IEEE80211_CHANNEL_TIME;
778 }
779
780 /* Now, just wait a bit and we are all done! */
781 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
782 next_delay);
783 return 0;
784 } else {
785 /* Do normal software scan */
786 __set_bit(SCAN_SW_SCANNING, &local->scanning);
787 }
788
789 ieee80211_recalc_idle(local);
790
791 if (hw_scan) {
792 WARN_ON(!ieee80211_prep_hw_scan(sdata));
793 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
794 } else {
795 rc = ieee80211_start_sw_scan(local, sdata);
796 }
797
798 if (rc) {
799 kfree(local->hw_scan_req);
800 local->hw_scan_req = NULL;
801 local->scanning = 0;
802
803 ieee80211_recalc_idle(local);
804
805 local->scan_req = NULL;
806 RCU_INIT_POINTER(local->scan_sdata, NULL);
807 }
808
809 if (hw_scan && rc == 1) {
810 /*
811 * we can't fall back to software for P2P-GO
812 * as it must update NoA etc.
813 */
814 if (ieee80211_vif_type_p2p(&sdata->vif) ==
815 NL80211_IFTYPE_P2P_GO)
816 return -EOPNOTSUPP;
817 hw_scan = false;
818 goto again;
819 }
820
821 return rc;
822 }
823
824 static unsigned long
ieee80211_scan_get_channel_time(struct ieee80211_channel * chan)825 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
826 {
827 /*
828 * TODO: channel switching also consumes quite some time,
829 * add that delay as well to get a better estimation
830 */
831 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
832 return IEEE80211_PASSIVE_CHANNEL_TIME;
833 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
834 }
835
ieee80211_scan_state_decision(struct ieee80211_local * local,unsigned long * next_delay)836 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
837 unsigned long *next_delay)
838 {
839 bool associated = false;
840 bool tx_empty = true;
841 bool bad_latency;
842 struct ieee80211_sub_if_data *sdata;
843 struct ieee80211_channel *next_chan;
844 enum mac80211_scan_state next_scan_state;
845 struct cfg80211_scan_request *scan_req;
846
847 /*
848 * check if at least one STA interface is associated,
849 * check if at least one STA interface has pending tx frames
850 * and grab the lowest used beacon interval
851 */
852 mutex_lock(&local->iflist_mtx);
853 list_for_each_entry(sdata, &local->interfaces, list) {
854 if (!ieee80211_sdata_running(sdata))
855 continue;
856
857 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
858 if (sdata->u.mgd.associated) {
859 associated = true;
860
861 if (!qdisc_all_tx_empty(sdata->dev)) {
862 tx_empty = false;
863 break;
864 }
865 }
866 }
867 }
868 mutex_unlock(&local->iflist_mtx);
869
870 scan_req = rcu_dereference_protected(local->scan_req,
871 lockdep_is_held(&local->mtx));
872
873 next_chan = scan_req->channels[local->scan_channel_idx];
874
875 /*
876 * we're currently scanning a different channel, let's
877 * see if we can scan another channel without interfering
878 * with the current traffic situation.
879 *
880 * Keep good latency, do not stay off-channel more than 125 ms.
881 */
882
883 bad_latency = time_after(jiffies +
884 ieee80211_scan_get_channel_time(next_chan),
885 local->leave_oper_channel_time + HZ / 8);
886
887 if (associated && !tx_empty) {
888 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
889 next_scan_state = SCAN_ABORT;
890 else
891 next_scan_state = SCAN_SUSPEND;
892 } else if (associated && bad_latency) {
893 next_scan_state = SCAN_SUSPEND;
894 } else {
895 next_scan_state = SCAN_SET_CHANNEL;
896 }
897
898 local->next_scan_state = next_scan_state;
899
900 *next_delay = 0;
901 }
902
ieee80211_scan_state_set_channel(struct ieee80211_local * local,unsigned long * next_delay)903 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
904 unsigned long *next_delay)
905 {
906 int skip;
907 struct ieee80211_channel *chan;
908 enum nl80211_bss_scan_width oper_scan_width;
909 struct cfg80211_scan_request *scan_req;
910
911 scan_req = rcu_dereference_protected(local->scan_req,
912 lockdep_is_held(&local->mtx));
913
914 skip = 0;
915 chan = scan_req->channels[local->scan_channel_idx];
916
917 local->scan_chandef.chan = chan;
918 local->scan_chandef.center_freq1 = chan->center_freq;
919 local->scan_chandef.freq1_offset = chan->freq_offset;
920 local->scan_chandef.center_freq2 = 0;
921
922 /* For scanning on the S1G band, ignore scan_width (which is constant
923 * across all channels) for now since channel width is specific to each
924 * channel. Detect the required channel width here and likely revisit
925 * later. Maybe scan_width could be used to build the channel scan list?
926 */
927 if (chan->band == NL80211_BAND_S1GHZ) {
928 local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
929 goto set_channel;
930 }
931
932 switch (scan_req->scan_width) {
933 case NL80211_BSS_CHAN_WIDTH_5:
934 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
935 break;
936 case NL80211_BSS_CHAN_WIDTH_10:
937 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
938 break;
939 default:
940 case NL80211_BSS_CHAN_WIDTH_20:
941 /* If scanning on oper channel, use whatever channel-type
942 * is currently in use.
943 */
944 oper_scan_width = cfg80211_chandef_to_scan_width(
945 &local->_oper_chandef);
946 if (chan == local->_oper_chandef.chan &&
947 oper_scan_width == scan_req->scan_width)
948 local->scan_chandef = local->_oper_chandef;
949 else
950 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
951 break;
952 case NL80211_BSS_CHAN_WIDTH_1:
953 case NL80211_BSS_CHAN_WIDTH_2:
954 /* shouldn't get here, S1G handled above */
955 WARN_ON(1);
956 break;
957 }
958
959 set_channel:
960 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
961 skip = 1;
962
963 /* advance state machine to next channel/band */
964 local->scan_channel_idx++;
965
966 if (skip) {
967 /* if we skip this channel return to the decision state */
968 local->next_scan_state = SCAN_DECISION;
969 return;
970 }
971
972 /*
973 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
974 * (which unfortunately doesn't say _why_ step a) is done,
975 * but it waits for the probe delay or until a frame is
976 * received - and the received frame would update the NAV).
977 * For now, we do not support waiting until a frame is
978 * received.
979 *
980 * In any case, it is not necessary for a passive scan.
981 */
982 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
983 !scan_req->n_ssids) {
984 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
985 local->next_scan_state = SCAN_DECISION;
986 return;
987 }
988
989 /* active scan, send probes */
990 *next_delay = IEEE80211_PROBE_DELAY;
991 local->next_scan_state = SCAN_SEND_PROBE;
992 }
993
ieee80211_scan_state_suspend(struct ieee80211_local * local,unsigned long * next_delay)994 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
995 unsigned long *next_delay)
996 {
997 /* switch back to the operating channel */
998 local->scan_chandef.chan = NULL;
999 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
1000
1001 /* disable PS */
1002 ieee80211_offchannel_return(local);
1003
1004 *next_delay = HZ / 5;
1005 /* afterwards, resume scan & go to next channel */
1006 local->next_scan_state = SCAN_RESUME;
1007 }
1008
ieee80211_scan_state_resume(struct ieee80211_local * local,unsigned long * next_delay)1009 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1010 unsigned long *next_delay)
1011 {
1012 ieee80211_offchannel_stop_vifs(local);
1013
1014 if (local->ops->flush) {
1015 ieee80211_flush_queues(local, NULL, false);
1016 *next_delay = 0;
1017 } else
1018 *next_delay = HZ / 10;
1019
1020 /* remember when we left the operating channel */
1021 local->leave_oper_channel_time = jiffies;
1022
1023 /* advance to the next channel to be scanned */
1024 local->next_scan_state = SCAN_SET_CHANNEL;
1025 }
1026
ieee80211_scan_work(struct work_struct * work)1027 void ieee80211_scan_work(struct work_struct *work)
1028 {
1029 struct ieee80211_local *local =
1030 container_of(work, struct ieee80211_local, scan_work.work);
1031 struct ieee80211_sub_if_data *sdata;
1032 struct cfg80211_scan_request *scan_req;
1033 unsigned long next_delay = 0;
1034 bool aborted;
1035
1036 mutex_lock(&local->mtx);
1037
1038 if (!ieee80211_can_run_worker(local)) {
1039 aborted = true;
1040 goto out_complete;
1041 }
1042
1043 sdata = rcu_dereference_protected(local->scan_sdata,
1044 lockdep_is_held(&local->mtx));
1045 scan_req = rcu_dereference_protected(local->scan_req,
1046 lockdep_is_held(&local->mtx));
1047
1048 /* When scanning on-channel, the first-callback means completed. */
1049 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1050 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1051 goto out_complete;
1052 }
1053
1054 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1055 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1056 goto out_complete;
1057 }
1058
1059 if (!sdata || !scan_req)
1060 goto out;
1061
1062 if (!local->scanning) {
1063 int rc;
1064
1065 RCU_INIT_POINTER(local->scan_req, NULL);
1066 RCU_INIT_POINTER(local->scan_sdata, NULL);
1067
1068 rc = __ieee80211_start_scan(sdata, scan_req);
1069 if (rc) {
1070 /* need to complete scan in cfg80211 */
1071 rcu_assign_pointer(local->scan_req, scan_req);
1072 aborted = true;
1073 goto out_complete;
1074 } else
1075 goto out;
1076 }
1077
1078 /*
1079 * as long as no delay is required advance immediately
1080 * without scheduling a new work
1081 */
1082 do {
1083 if (!ieee80211_sdata_running(sdata)) {
1084 aborted = true;
1085 goto out_complete;
1086 }
1087
1088 switch (local->next_scan_state) {
1089 case SCAN_DECISION:
1090 /* if no more bands/channels left, complete scan */
1091 if (local->scan_channel_idx >= scan_req->n_channels) {
1092 aborted = false;
1093 goto out_complete;
1094 }
1095 ieee80211_scan_state_decision(local, &next_delay);
1096 break;
1097 case SCAN_SET_CHANNEL:
1098 ieee80211_scan_state_set_channel(local, &next_delay);
1099 break;
1100 case SCAN_SEND_PROBE:
1101 ieee80211_scan_state_send_probe(local, &next_delay);
1102 break;
1103 case SCAN_SUSPEND:
1104 ieee80211_scan_state_suspend(local, &next_delay);
1105 break;
1106 case SCAN_RESUME:
1107 ieee80211_scan_state_resume(local, &next_delay);
1108 break;
1109 case SCAN_ABORT:
1110 aborted = true;
1111 goto out_complete;
1112 }
1113 } while (next_delay == 0);
1114
1115 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
1116 goto out;
1117
1118 out_complete:
1119 __ieee80211_scan_completed(&local->hw, aborted);
1120 out:
1121 mutex_unlock(&local->mtx);
1122 }
1123
ieee80211_request_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)1124 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1125 struct cfg80211_scan_request *req)
1126 {
1127 int res;
1128
1129 mutex_lock(&sdata->local->mtx);
1130 res = __ieee80211_start_scan(sdata, req);
1131 mutex_unlock(&sdata->local->mtx);
1132
1133 return res;
1134 }
1135
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)1136 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1137 const u8 *ssid, u8 ssid_len,
1138 struct ieee80211_channel **channels,
1139 unsigned int n_channels,
1140 enum nl80211_bss_scan_width scan_width)
1141 {
1142 struct ieee80211_local *local = sdata->local;
1143 int ret = -EBUSY, i, n_ch = 0;
1144 enum nl80211_band band;
1145
1146 mutex_lock(&local->mtx);
1147
1148 /* busy scanning */
1149 if (local->scan_req)
1150 goto unlock;
1151
1152 /* fill internal scan request */
1153 if (!channels) {
1154 int max_n;
1155
1156 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1157 if (!local->hw.wiphy->bands[band] ||
1158 band == NL80211_BAND_6GHZ)
1159 continue;
1160
1161 max_n = local->hw.wiphy->bands[band]->n_channels;
1162 for (i = 0; i < max_n; i++) {
1163 struct ieee80211_channel *tmp_ch =
1164 &local->hw.wiphy->bands[band]->channels[i];
1165
1166 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1167 IEEE80211_CHAN_DISABLED))
1168 continue;
1169
1170 local->int_scan_req->channels[n_ch] = tmp_ch;
1171 n_ch++;
1172 }
1173 }
1174
1175 if (WARN_ON_ONCE(n_ch == 0))
1176 goto unlock;
1177
1178 local->int_scan_req->n_channels = n_ch;
1179 } else {
1180 for (i = 0; i < n_channels; i++) {
1181 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1182 IEEE80211_CHAN_DISABLED))
1183 continue;
1184
1185 local->int_scan_req->channels[n_ch] = channels[i];
1186 n_ch++;
1187 }
1188
1189 if (WARN_ON_ONCE(n_ch == 0))
1190 goto unlock;
1191
1192 local->int_scan_req->n_channels = n_ch;
1193 }
1194
1195 local->int_scan_req->ssids = &local->scan_ssid;
1196 local->int_scan_req->n_ssids = 1;
1197 local->int_scan_req->scan_width = scan_width;
1198 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1199 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1200
1201 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1202 unlock:
1203 mutex_unlock(&local->mtx);
1204 return ret;
1205 }
1206
1207 /*
1208 * Only call this function when a scan can't be queued -- under RTNL.
1209 */
ieee80211_scan_cancel(struct ieee80211_local * local)1210 void ieee80211_scan_cancel(struct ieee80211_local *local)
1211 {
1212 /*
1213 * We are canceling software scan, or deferred scan that was not
1214 * yet really started (see __ieee80211_start_scan ).
1215 *
1216 * Regarding hardware scan:
1217 * - we can not call __ieee80211_scan_completed() as when
1218 * SCAN_HW_SCANNING bit is set this function change
1219 * local->hw_scan_req to operate on 5G band, what race with
1220 * driver which can use local->hw_scan_req
1221 *
1222 * - we can not cancel scan_work since driver can schedule it
1223 * by ieee80211_scan_completed(..., true) to finish scan
1224 *
1225 * Hence we only call the cancel_hw_scan() callback, but the low-level
1226 * driver is still responsible for calling ieee80211_scan_completed()
1227 * after the scan was completed/aborted.
1228 */
1229
1230 mutex_lock(&local->mtx);
1231 if (!local->scan_req)
1232 goto out;
1233
1234 /*
1235 * We have a scan running and the driver already reported completion,
1236 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1237 * cancelled.
1238 */
1239 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1240 test_bit(SCAN_COMPLETED, &local->scanning)) {
1241 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1242 goto out;
1243 }
1244
1245 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1246 /*
1247 * Make sure that __ieee80211_scan_completed doesn't trigger a
1248 * scan on another band.
1249 */
1250 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1251 if (local->ops->cancel_hw_scan)
1252 drv_cancel_hw_scan(local,
1253 rcu_dereference_protected(local->scan_sdata,
1254 lockdep_is_held(&local->mtx)));
1255 goto out;
1256 }
1257
1258 /*
1259 * If the work is currently running, it must be blocked on
1260 * the mutex, but we'll set scan_sdata = NULL and it'll
1261 * simply exit once it acquires the mutex.
1262 */
1263 cancel_delayed_work(&local->scan_work);
1264 /* and clean up */
1265 memset(&local->scan_info, 0, sizeof(local->scan_info));
1266 __ieee80211_scan_completed(&local->hw, true);
1267 out:
1268 mutex_unlock(&local->mtx);
1269 }
1270
__ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1271 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1272 struct cfg80211_sched_scan_request *req)
1273 {
1274 struct ieee80211_local *local = sdata->local;
1275 struct ieee80211_scan_ies sched_scan_ies = {};
1276 struct cfg80211_chan_def chandef;
1277 int ret, i, iebufsz, num_bands = 0;
1278 u32 rate_masks[NUM_NL80211_BANDS] = {};
1279 u8 bands_used = 0;
1280 u8 *ie;
1281 u32 flags = 0;
1282
1283 iebufsz = local->scan_ies_len + req->ie_len;
1284
1285 lockdep_assert_held(&local->mtx);
1286
1287 if (!local->ops->sched_scan_start)
1288 return -ENOTSUPP;
1289
1290 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1291 if (local->hw.wiphy->bands[i]) {
1292 bands_used |= BIT(i);
1293 rate_masks[i] = (u32) -1;
1294 num_bands++;
1295 }
1296 }
1297
1298 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1299 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1300
1301 ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1302 if (!ie) {
1303 ret = -ENOMEM;
1304 goto out;
1305 }
1306
1307 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1308
1309 ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1310 &sched_scan_ies, req->ie,
1311 req->ie_len, bands_used, rate_masks, &chandef,
1312 flags);
1313
1314 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1315 if (ret == 0) {
1316 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1317 rcu_assign_pointer(local->sched_scan_req, req);
1318 }
1319
1320 kfree(ie);
1321
1322 out:
1323 if (ret) {
1324 /* Clean in case of failure after HW restart or upon resume. */
1325 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1326 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1327 }
1328
1329 return ret;
1330 }
1331
ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1332 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1333 struct cfg80211_sched_scan_request *req)
1334 {
1335 struct ieee80211_local *local = sdata->local;
1336 int ret;
1337
1338 mutex_lock(&local->mtx);
1339
1340 if (rcu_access_pointer(local->sched_scan_sdata)) {
1341 mutex_unlock(&local->mtx);
1342 return -EBUSY;
1343 }
1344
1345 ret = __ieee80211_request_sched_scan_start(sdata, req);
1346
1347 mutex_unlock(&local->mtx);
1348 return ret;
1349 }
1350
ieee80211_request_sched_scan_stop(struct ieee80211_local * local)1351 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1352 {
1353 struct ieee80211_sub_if_data *sched_scan_sdata;
1354 int ret = -ENOENT;
1355
1356 mutex_lock(&local->mtx);
1357
1358 if (!local->ops->sched_scan_stop) {
1359 ret = -ENOTSUPP;
1360 goto out;
1361 }
1362
1363 /* We don't want to restart sched scan anymore. */
1364 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1365
1366 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1367 lockdep_is_held(&local->mtx));
1368 if (sched_scan_sdata) {
1369 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1370 if (!ret)
1371 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1372 }
1373 out:
1374 mutex_unlock(&local->mtx);
1375
1376 return ret;
1377 }
1378
ieee80211_sched_scan_results(struct ieee80211_hw * hw)1379 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1380 {
1381 struct ieee80211_local *local = hw_to_local(hw);
1382
1383 trace_api_sched_scan_results(local);
1384
1385 cfg80211_sched_scan_results(hw->wiphy, 0);
1386 }
1387 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1388
ieee80211_sched_scan_end(struct ieee80211_local * local)1389 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1390 {
1391 mutex_lock(&local->mtx);
1392
1393 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1394 mutex_unlock(&local->mtx);
1395 return;
1396 }
1397
1398 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1399
1400 /* If sched scan was aborted by the driver. */
1401 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1402
1403 mutex_unlock(&local->mtx);
1404
1405 cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1406 }
1407
ieee80211_sched_scan_stopped_work(struct work_struct * work)1408 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1409 {
1410 struct ieee80211_local *local =
1411 container_of(work, struct ieee80211_local,
1412 sched_scan_stopped_work);
1413
1414 ieee80211_sched_scan_end(local);
1415 }
1416
ieee80211_sched_scan_stopped(struct ieee80211_hw * hw)1417 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1418 {
1419 struct ieee80211_local *local = hw_to_local(hw);
1420
1421 trace_api_sched_scan_stopped(local);
1422
1423 /*
1424 * this shouldn't really happen, so for simplicity
1425 * simply ignore it, and let mac80211 reconfigure
1426 * the sched scan later on.
1427 */
1428 if (local->in_reconfig)
1429 return;
1430
1431 schedule_work(&local->sched_scan_stopped_work);
1432 }
1433 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
1434
