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) 2018-2021 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 elems = ieee802_11_parse_elems(elements, len - baselen, false,
213 mgmt->bssid, cbss->bssid);
214 if (!elems)
215 return NULL;
216
217 /* In case the signal is invalid update the status */
218 signal_valid = channel == cbss->channel;
219 if (!signal_valid)
220 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
221
222 bss = (void *)cbss->priv;
223 ieee80211_update_bss_from_elems(local, bss, elems, rx_status, beacon);
224
225 list_for_each_entry(non_tx_cbss, &cbss->nontrans_list, nontrans_list) {
226 non_tx_bss = (void *)non_tx_cbss->priv;
227
228 ieee80211_update_bss_from_elems(local, non_tx_bss, elems,
229 rx_status, beacon);
230 }
231
232 kfree(elems);
233
234 return bss;
235 }
236
ieee80211_scan_accept_presp(struct ieee80211_sub_if_data * sdata,u32 scan_flags,const u8 * da)237 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
238 u32 scan_flags, const u8 *da)
239 {
240 if (!sdata)
241 return false;
242 /* accept broadcast for OCE */
243 if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
244 is_broadcast_ether_addr(da))
245 return true;
246 if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
247 return true;
248 return ether_addr_equal(da, sdata->vif.addr);
249 }
250
ieee80211_scan_rx(struct ieee80211_local * local,struct sk_buff * skb)251 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
252 {
253 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
254 struct ieee80211_sub_if_data *sdata1, *sdata2;
255 struct ieee80211_mgmt *mgmt = (void *)skb->data;
256 struct ieee80211_bss *bss;
257 struct ieee80211_channel *channel;
258 size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
259 u.probe_resp.variable);
260
261 if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
262 !ieee80211_is_beacon(mgmt->frame_control) &&
263 !ieee80211_is_s1g_beacon(mgmt->frame_control))
264 return;
265
266 if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
267 if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
268 min_hdr_len = offsetof(struct ieee80211_ext,
269 u.s1g_short_beacon.variable);
270 else
271 min_hdr_len = offsetof(struct ieee80211_ext,
272 u.s1g_beacon);
273 }
274
275 if (skb->len < min_hdr_len)
276 return;
277
278 sdata1 = rcu_dereference(local->scan_sdata);
279 sdata2 = rcu_dereference(local->sched_scan_sdata);
280
281 if (likely(!sdata1 && !sdata2))
282 return;
283
284 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
285 struct cfg80211_scan_request *scan_req;
286 struct cfg80211_sched_scan_request *sched_scan_req;
287 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
288
289 scan_req = rcu_dereference(local->scan_req);
290 sched_scan_req = rcu_dereference(local->sched_scan_req);
291
292 if (scan_req)
293 scan_req_flags = scan_req->flags;
294
295 if (sched_scan_req)
296 sched_scan_req_flags = sched_scan_req->flags;
297
298 /* ignore ProbeResp to foreign address or non-bcast (OCE)
299 * unless scanning with randomised address
300 */
301 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
302 mgmt->da) &&
303 !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
304 mgmt->da))
305 return;
306 }
307
308 channel = ieee80211_get_channel_khz(local->hw.wiphy,
309 ieee80211_rx_status_to_khz(rx_status));
310
311 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
312 return;
313
314 bss = ieee80211_bss_info_update(local, rx_status,
315 mgmt, skb->len,
316 channel);
317 if (bss)
318 ieee80211_rx_bss_put(local, bss);
319 }
320
321 static void
ieee80211_prepare_scan_chandef(struct cfg80211_chan_def * chandef,enum nl80211_bss_scan_width scan_width)322 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
323 enum nl80211_bss_scan_width scan_width)
324 {
325 memset(chandef, 0, sizeof(*chandef));
326 switch (scan_width) {
327 case NL80211_BSS_CHAN_WIDTH_5:
328 chandef->width = NL80211_CHAN_WIDTH_5;
329 break;
330 case NL80211_BSS_CHAN_WIDTH_10:
331 chandef->width = NL80211_CHAN_WIDTH_10;
332 break;
333 default:
334 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
335 break;
336 }
337 }
338
339 /* return false if no more work */
ieee80211_prep_hw_scan(struct ieee80211_sub_if_data * sdata)340 static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
341 {
342 struct ieee80211_local *local = sdata->local;
343 struct cfg80211_scan_request *req;
344 struct cfg80211_chan_def chandef;
345 u8 bands_used = 0;
346 int i, ielen, n_chans;
347 u32 flags = 0;
348
349 req = rcu_dereference_protected(local->scan_req,
350 lockdep_is_held(&local->mtx));
351
352 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
353 return false;
354
355 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
356 for (i = 0; i < req->n_channels; i++) {
357 local->hw_scan_req->req.channels[i] = req->channels[i];
358 bands_used |= BIT(req->channels[i]->band);
359 }
360
361 n_chans = req->n_channels;
362 } else {
363 do {
364 if (local->hw_scan_band == NUM_NL80211_BANDS)
365 return false;
366
367 n_chans = 0;
368
369 for (i = 0; i < req->n_channels; i++) {
370 if (req->channels[i]->band !=
371 local->hw_scan_band)
372 continue;
373 local->hw_scan_req->req.channels[n_chans] =
374 req->channels[i];
375 n_chans++;
376 bands_used |= BIT(req->channels[i]->band);
377 }
378
379 local->hw_scan_band++;
380 } while (!n_chans);
381 }
382
383 local->hw_scan_req->req.n_channels = n_chans;
384 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
385
386 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
387 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
388
389 ielen = ieee80211_build_preq_ies(sdata,
390 (u8 *)local->hw_scan_req->req.ie,
391 local->hw_scan_ies_bufsize,
392 &local->hw_scan_req->ies,
393 req->ie, req->ie_len,
394 bands_used, req->rates, &chandef,
395 flags);
396 local->hw_scan_req->req.ie_len = ielen;
397 local->hw_scan_req->req.no_cck = req->no_cck;
398 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
399 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
400 req->mac_addr_mask);
401 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
402
403 return true;
404 }
405
__ieee80211_scan_completed(struct ieee80211_hw * hw,bool aborted)406 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
407 {
408 struct ieee80211_local *local = hw_to_local(hw);
409 bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
410 bool was_scanning = local->scanning;
411 struct cfg80211_scan_request *scan_req;
412 struct ieee80211_sub_if_data *scan_sdata;
413 struct ieee80211_sub_if_data *sdata;
414
415 lockdep_assert_held(&local->mtx);
416
417 /*
418 * It's ok to abort a not-yet-running scan (that
419 * we have one at all will be verified by checking
420 * local->scan_req next), but not to complete it
421 * successfully.
422 */
423 if (WARN_ON(!local->scanning && !aborted))
424 aborted = true;
425
426 if (WARN_ON(!local->scan_req))
427 return;
428
429 scan_sdata = rcu_dereference_protected(local->scan_sdata,
430 lockdep_is_held(&local->mtx));
431
432 if (hw_scan && !aborted &&
433 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
434 ieee80211_prep_hw_scan(scan_sdata)) {
435 int rc;
436
437 rc = drv_hw_scan(local,
438 rcu_dereference_protected(local->scan_sdata,
439 lockdep_is_held(&local->mtx)),
440 local->hw_scan_req);
441
442 if (rc == 0)
443 return;
444
445 /* HW scan failed and is going to be reported as aborted,
446 * so clear old scan info.
447 */
448 memset(&local->scan_info, 0, sizeof(local->scan_info));
449 aborted = true;
450 }
451
452 kfree(local->hw_scan_req);
453 local->hw_scan_req = NULL;
454
455 scan_req = rcu_dereference_protected(local->scan_req,
456 lockdep_is_held(&local->mtx));
457
458 if (scan_req != local->int_scan_req) {
459 local->scan_info.aborted = aborted;
460 cfg80211_scan_done(scan_req, &local->scan_info);
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 /* Set power back to normal operating levels. */
469 ieee80211_hw_config(local, 0);
470
471 if (!hw_scan) {
472 ieee80211_configure_filter(local);
473 drv_sw_scan_complete(local, scan_sdata);
474 ieee80211_offchannel_return(local);
475 }
476
477 ieee80211_recalc_idle(local);
478
479 ieee80211_mlme_notify_scan_completed(local);
480 ieee80211_ibss_notify_scan_completed(local);
481
482 /* Requeue all the work that might have been ignored while
483 * the scan was in progress; if there was none this will
484 * just be a no-op for the particular interface.
485 */
486 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
487 if (ieee80211_sdata_running(sdata))
488 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
489 }
490
491 if (was_scanning)
492 ieee80211_start_next_roc(local);
493 }
494
ieee80211_scan_completed(struct ieee80211_hw * hw,struct cfg80211_scan_info * info)495 void ieee80211_scan_completed(struct ieee80211_hw *hw,
496 struct cfg80211_scan_info *info)
497 {
498 struct ieee80211_local *local = hw_to_local(hw);
499
500 trace_api_scan_completed(local, info->aborted);
501
502 set_bit(SCAN_COMPLETED, &local->scanning);
503 if (info->aborted)
504 set_bit(SCAN_ABORTED, &local->scanning);
505
506 memcpy(&local->scan_info, info, sizeof(*info));
507
508 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
509 }
510 EXPORT_SYMBOL(ieee80211_scan_completed);
511
ieee80211_start_sw_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)512 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
513 struct ieee80211_sub_if_data *sdata)
514 {
515 /* Software scan is not supported in multi-channel cases */
516 if (local->use_chanctx)
517 return -EOPNOTSUPP;
518
519 /*
520 * Hardware/driver doesn't support hw_scan, so use software
521 * scanning instead. First send a nullfunc frame with power save
522 * bit on so that AP will buffer the frames for us while we are not
523 * listening, then send probe requests to each channel and wait for
524 * the responses. After all channels are scanned, tune back to the
525 * original channel and send a nullfunc frame with power save bit
526 * off to trigger the AP to send us all the buffered frames.
527 *
528 * Note that while local->sw_scanning is true everything else but
529 * nullfunc frames and probe requests will be dropped in
530 * ieee80211_tx_h_check_assoc().
531 */
532 drv_sw_scan_start(local, sdata, local->scan_addr);
533
534 local->leave_oper_channel_time = jiffies;
535 local->next_scan_state = SCAN_DECISION;
536 local->scan_channel_idx = 0;
537
538 ieee80211_offchannel_stop_vifs(local);
539
540 /* ensure nullfunc is transmitted before leaving operating channel */
541 ieee80211_flush_queues(local, NULL, false);
542
543 ieee80211_configure_filter(local);
544
545 /* We need to set power level at maximum rate for scanning. */
546 ieee80211_hw_config(local, 0);
547
548 ieee80211_queue_delayed_work(&local->hw,
549 &local->scan_work, 0);
550
551 return 0;
552 }
553
__ieee80211_can_leave_ch(struct ieee80211_sub_if_data * sdata)554 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
555 {
556 struct ieee80211_local *local = sdata->local;
557 struct ieee80211_sub_if_data *sdata_iter;
558
559 if (!ieee80211_is_radar_required(local))
560 return true;
561
562 if (!regulatory_pre_cac_allowed(local->hw.wiphy))
563 return false;
564
565 mutex_lock(&local->iflist_mtx);
566 list_for_each_entry(sdata_iter, &local->interfaces, list) {
567 if (sdata_iter->wdev.cac_started) {
568 mutex_unlock(&local->iflist_mtx);
569 return false;
570 }
571 }
572 mutex_unlock(&local->iflist_mtx);
573
574 return true;
575 }
576
ieee80211_can_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)577 static bool ieee80211_can_scan(struct ieee80211_local *local,
578 struct ieee80211_sub_if_data *sdata)
579 {
580 if (!__ieee80211_can_leave_ch(sdata))
581 return false;
582
583 if (!list_empty(&local->roc_list))
584 return false;
585
586 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
587 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
588 return false;
589
590 return true;
591 }
592
ieee80211_run_deferred_scan(struct ieee80211_local * local)593 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
594 {
595 lockdep_assert_held(&local->mtx);
596
597 if (!local->scan_req || local->scanning)
598 return;
599
600 if (!ieee80211_can_scan(local,
601 rcu_dereference_protected(
602 local->scan_sdata,
603 lockdep_is_held(&local->mtx))))
604 return;
605
606 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
607 round_jiffies_relative(0));
608 }
609
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)610 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
611 const u8 *src, const u8 *dst,
612 const u8 *ssid, size_t ssid_len,
613 const u8 *ie, size_t ie_len,
614 u32 ratemask, u32 flags, u32 tx_flags,
615 struct ieee80211_channel *channel)
616 {
617 struct sk_buff *skb;
618
619 skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
620 ssid, ssid_len,
621 ie, ie_len, flags);
622
623 if (skb) {
624 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
625 struct ieee80211_hdr *hdr = (void *)skb->data;
626 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
627 u16 sn = get_random_u32();
628
629 info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
630 hdr->seq_ctrl =
631 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
632 }
633 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
634 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
635 }
636 }
637
ieee80211_scan_state_send_probe(struct ieee80211_local * local,unsigned long * next_delay)638 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
639 unsigned long *next_delay)
640 {
641 int i;
642 struct ieee80211_sub_if_data *sdata;
643 struct cfg80211_scan_request *scan_req;
644 enum nl80211_band band = local->hw.conf.chandef.chan->band;
645 u32 flags = 0, tx_flags;
646
647 scan_req = rcu_dereference_protected(local->scan_req,
648 lockdep_is_held(&local->mtx));
649
650 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
651 if (scan_req->no_cck)
652 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
653 if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
654 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
655 if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
656 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
657
658 sdata = rcu_dereference_protected(local->scan_sdata,
659 lockdep_is_held(&local->mtx));
660
661 for (i = 0; i < scan_req->n_ssids; i++)
662 ieee80211_send_scan_probe_req(
663 sdata, local->scan_addr, scan_req->bssid,
664 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
665 scan_req->ie, scan_req->ie_len,
666 scan_req->rates[band], flags,
667 tx_flags, local->hw.conf.chandef.chan);
668
669 /*
670 * After sending probe requests, wait for probe responses
671 * on the channel.
672 */
673 *next_delay = IEEE80211_CHANNEL_TIME;
674 local->next_scan_state = SCAN_DECISION;
675 }
676
__ieee80211_start_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)677 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
678 struct cfg80211_scan_request *req)
679 {
680 struct ieee80211_local *local = sdata->local;
681 bool hw_scan = local->ops->hw_scan;
682 int rc;
683
684 lockdep_assert_held(&local->mtx);
685
686 if (local->scan_req)
687 return -EBUSY;
688
689 if (!__ieee80211_can_leave_ch(sdata))
690 return -EBUSY;
691
692 if (!ieee80211_can_scan(local, sdata)) {
693 /* wait for the work to finish/time out */
694 rcu_assign_pointer(local->scan_req, req);
695 rcu_assign_pointer(local->scan_sdata, sdata);
696 return 0;
697 }
698
699 again:
700 if (hw_scan) {
701 u8 *ies;
702
703 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
704
705 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
706 int i, n_bands = 0;
707 u8 bands_counted = 0;
708
709 for (i = 0; i < req->n_channels; i++) {
710 if (bands_counted & BIT(req->channels[i]->band))
711 continue;
712 bands_counted |= BIT(req->channels[i]->band);
713 n_bands++;
714 }
715
716 local->hw_scan_ies_bufsize *= n_bands;
717 }
718
719 local->hw_scan_req = kmalloc(
720 sizeof(*local->hw_scan_req) +
721 req->n_channels * sizeof(req->channels[0]) +
722 local->hw_scan_ies_bufsize, GFP_KERNEL);
723 if (!local->hw_scan_req)
724 return -ENOMEM;
725
726 local->hw_scan_req->req.ssids = req->ssids;
727 local->hw_scan_req->req.n_ssids = req->n_ssids;
728 ies = (u8 *)local->hw_scan_req +
729 sizeof(*local->hw_scan_req) +
730 req->n_channels * sizeof(req->channels[0]);
731 local->hw_scan_req->req.ie = ies;
732 local->hw_scan_req->req.flags = req->flags;
733 eth_broadcast_addr(local->hw_scan_req->req.bssid);
734 local->hw_scan_req->req.duration = req->duration;
735 local->hw_scan_req->req.duration_mandatory =
736 req->duration_mandatory;
737
738 local->hw_scan_band = 0;
739 local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
740 local->hw_scan_req->req.scan_6ghz_params =
741 req->scan_6ghz_params;
742 local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
743
744 /*
745 * After allocating local->hw_scan_req, we must
746 * go through until ieee80211_prep_hw_scan(), so
747 * anything that might be changed here and leave
748 * this function early must not go after this
749 * allocation.
750 */
751 }
752
753 rcu_assign_pointer(local->scan_req, req);
754 rcu_assign_pointer(local->scan_sdata, sdata);
755
756 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
757 get_random_mask_addr(local->scan_addr,
758 req->mac_addr,
759 req->mac_addr_mask);
760 else
761 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
762
763 if (hw_scan) {
764 __set_bit(SCAN_HW_SCANNING, &local->scanning);
765 } else if ((req->n_channels == 1) &&
766 (req->channels[0] == local->_oper_chandef.chan)) {
767 /*
768 * If we are scanning only on the operating channel
769 * then we do not need to stop normal activities
770 */
771 unsigned long next_delay;
772
773 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
774
775 ieee80211_recalc_idle(local);
776
777 /* Notify driver scan is starting, keep order of operations
778 * same as normal software scan, in case that matters. */
779 drv_sw_scan_start(local, sdata, local->scan_addr);
780
781 ieee80211_configure_filter(local); /* accept probe-responses */
782
783 /* We need to ensure power level is at max for scanning. */
784 ieee80211_hw_config(local, 0);
785
786 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
787 IEEE80211_CHAN_RADAR)) ||
788 !req->n_ssids) {
789 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
790 } else {
791 ieee80211_scan_state_send_probe(local, &next_delay);
792 next_delay = IEEE80211_CHANNEL_TIME;
793 }
794
795 /* Now, just wait a bit and we are all done! */
796 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
797 next_delay);
798 return 0;
799 } else {
800 /* Do normal software scan */
801 __set_bit(SCAN_SW_SCANNING, &local->scanning);
802 }
803
804 ieee80211_recalc_idle(local);
805
806 if (hw_scan) {
807 WARN_ON(!ieee80211_prep_hw_scan(sdata));
808 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
809 } else {
810 rc = ieee80211_start_sw_scan(local, sdata);
811 }
812
813 if (rc) {
814 kfree(local->hw_scan_req);
815 local->hw_scan_req = NULL;
816 local->scanning = 0;
817
818 ieee80211_recalc_idle(local);
819
820 local->scan_req = NULL;
821 RCU_INIT_POINTER(local->scan_sdata, NULL);
822 }
823
824 if (hw_scan && rc == 1) {
825 /*
826 * we can't fall back to software for P2P-GO
827 * as it must update NoA etc.
828 */
829 if (ieee80211_vif_type_p2p(&sdata->vif) ==
830 NL80211_IFTYPE_P2P_GO)
831 return -EOPNOTSUPP;
832 hw_scan = false;
833 goto again;
834 }
835
836 return rc;
837 }
838
839 static unsigned long
ieee80211_scan_get_channel_time(struct ieee80211_channel * chan)840 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
841 {
842 /*
843 * TODO: channel switching also consumes quite some time,
844 * add that delay as well to get a better estimation
845 */
846 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
847 return IEEE80211_PASSIVE_CHANNEL_TIME;
848 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
849 }
850
ieee80211_scan_state_decision(struct ieee80211_local * local,unsigned long * next_delay)851 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
852 unsigned long *next_delay)
853 {
854 bool associated = false;
855 bool tx_empty = true;
856 bool bad_latency;
857 struct ieee80211_sub_if_data *sdata;
858 struct ieee80211_channel *next_chan;
859 enum mac80211_scan_state next_scan_state;
860 struct cfg80211_scan_request *scan_req;
861
862 /*
863 * check if at least one STA interface is associated,
864 * check if at least one STA interface has pending tx frames
865 * and grab the lowest used beacon interval
866 */
867 mutex_lock(&local->iflist_mtx);
868 list_for_each_entry(sdata, &local->interfaces, list) {
869 if (!ieee80211_sdata_running(sdata))
870 continue;
871
872 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
873 if (sdata->u.mgd.associated) {
874 associated = true;
875
876 if (!qdisc_all_tx_empty(sdata->dev)) {
877 tx_empty = false;
878 break;
879 }
880 }
881 }
882 }
883 mutex_unlock(&local->iflist_mtx);
884
885 scan_req = rcu_dereference_protected(local->scan_req,
886 lockdep_is_held(&local->mtx));
887
888 next_chan = scan_req->channels[local->scan_channel_idx];
889
890 /*
891 * we're currently scanning a different channel, let's
892 * see if we can scan another channel without interfering
893 * with the current traffic situation.
894 *
895 * Keep good latency, do not stay off-channel more than 125 ms.
896 */
897
898 bad_latency = time_after(jiffies +
899 ieee80211_scan_get_channel_time(next_chan),
900 local->leave_oper_channel_time + HZ / 8);
901
902 if (associated && !tx_empty) {
903 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
904 next_scan_state = SCAN_ABORT;
905 else
906 next_scan_state = SCAN_SUSPEND;
907 } else if (associated && bad_latency) {
908 next_scan_state = SCAN_SUSPEND;
909 } else {
910 next_scan_state = SCAN_SET_CHANNEL;
911 }
912
913 local->next_scan_state = next_scan_state;
914
915 *next_delay = 0;
916 }
917
ieee80211_scan_state_set_channel(struct ieee80211_local * local,unsigned long * next_delay)918 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
919 unsigned long *next_delay)
920 {
921 int skip;
922 struct ieee80211_channel *chan;
923 enum nl80211_bss_scan_width oper_scan_width;
924 struct cfg80211_scan_request *scan_req;
925
926 scan_req = rcu_dereference_protected(local->scan_req,
927 lockdep_is_held(&local->mtx));
928
929 skip = 0;
930 chan = scan_req->channels[local->scan_channel_idx];
931
932 local->scan_chandef.chan = chan;
933 local->scan_chandef.center_freq1 = chan->center_freq;
934 local->scan_chandef.freq1_offset = chan->freq_offset;
935 local->scan_chandef.center_freq2 = 0;
936
937 /* For scanning on the S1G band, ignore scan_width (which is constant
938 * across all channels) for now since channel width is specific to each
939 * channel. Detect the required channel width here and likely revisit
940 * later. Maybe scan_width could be used to build the channel scan list?
941 */
942 if (chan->band == NL80211_BAND_S1GHZ) {
943 local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
944 goto set_channel;
945 }
946
947 switch (scan_req->scan_width) {
948 case NL80211_BSS_CHAN_WIDTH_5:
949 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
950 break;
951 case NL80211_BSS_CHAN_WIDTH_10:
952 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
953 break;
954 default:
955 case NL80211_BSS_CHAN_WIDTH_20:
956 /* If scanning on oper channel, use whatever channel-type
957 * is currently in use.
958 */
959 oper_scan_width = cfg80211_chandef_to_scan_width(
960 &local->_oper_chandef);
961 if (chan == local->_oper_chandef.chan &&
962 oper_scan_width == scan_req->scan_width)
963 local->scan_chandef = local->_oper_chandef;
964 else
965 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
966 break;
967 case NL80211_BSS_CHAN_WIDTH_1:
968 case NL80211_BSS_CHAN_WIDTH_2:
969 /* shouldn't get here, S1G handled above */
970 WARN_ON(1);
971 break;
972 }
973
974 set_channel:
975 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
976 skip = 1;
977
978 /* advance state machine to next channel/band */
979 local->scan_channel_idx++;
980
981 if (skip) {
982 /* if we skip this channel return to the decision state */
983 local->next_scan_state = SCAN_DECISION;
984 return;
985 }
986
987 /*
988 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
989 * (which unfortunately doesn't say _why_ step a) is done,
990 * but it waits for the probe delay or until a frame is
991 * received - and the received frame would update the NAV).
992 * For now, we do not support waiting until a frame is
993 * received.
994 *
995 * In any case, it is not necessary for a passive scan.
996 */
997 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
998 !scan_req->n_ssids) {
999 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
1000 local->next_scan_state = SCAN_DECISION;
1001 return;
1002 }
1003
1004 /* active scan, send probes */
1005 *next_delay = IEEE80211_PROBE_DELAY;
1006 local->next_scan_state = SCAN_SEND_PROBE;
1007 }
1008
ieee80211_scan_state_suspend(struct ieee80211_local * local,unsigned long * next_delay)1009 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1010 unsigned long *next_delay)
1011 {
1012 /* switch back to the operating channel */
1013 local->scan_chandef.chan = NULL;
1014 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
1015
1016 /* disable PS */
1017 ieee80211_offchannel_return(local);
1018
1019 *next_delay = HZ / 5;
1020 /* afterwards, resume scan & go to next channel */
1021 local->next_scan_state = SCAN_RESUME;
1022 }
1023
ieee80211_scan_state_resume(struct ieee80211_local * local,unsigned long * next_delay)1024 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1025 unsigned long *next_delay)
1026 {
1027 ieee80211_offchannel_stop_vifs(local);
1028
1029 if (local->ops->flush) {
1030 ieee80211_flush_queues(local, NULL, false);
1031 *next_delay = 0;
1032 } else
1033 *next_delay = HZ / 10;
1034
1035 /* remember when we left the operating channel */
1036 local->leave_oper_channel_time = jiffies;
1037
1038 /* advance to the next channel to be scanned */
1039 local->next_scan_state = SCAN_SET_CHANNEL;
1040 }
1041
ieee80211_scan_work(struct work_struct * work)1042 void ieee80211_scan_work(struct work_struct *work)
1043 {
1044 struct ieee80211_local *local =
1045 container_of(work, struct ieee80211_local, scan_work.work);
1046 struct ieee80211_sub_if_data *sdata;
1047 struct cfg80211_scan_request *scan_req;
1048 unsigned long next_delay = 0;
1049 bool aborted;
1050
1051 mutex_lock(&local->mtx);
1052
1053 if (!ieee80211_can_run_worker(local)) {
1054 aborted = true;
1055 goto out_complete;
1056 }
1057
1058 sdata = rcu_dereference_protected(local->scan_sdata,
1059 lockdep_is_held(&local->mtx));
1060 scan_req = rcu_dereference_protected(local->scan_req,
1061 lockdep_is_held(&local->mtx));
1062
1063 /* When scanning on-channel, the first-callback means completed. */
1064 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1065 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1066 goto out_complete;
1067 }
1068
1069 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1070 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1071 goto out_complete;
1072 }
1073
1074 if (!sdata || !scan_req)
1075 goto out;
1076
1077 if (!local->scanning) {
1078 int rc;
1079
1080 RCU_INIT_POINTER(local->scan_req, NULL);
1081 RCU_INIT_POINTER(local->scan_sdata, NULL);
1082
1083 rc = __ieee80211_start_scan(sdata, scan_req);
1084 if (rc) {
1085 /* need to complete scan in cfg80211 */
1086 rcu_assign_pointer(local->scan_req, scan_req);
1087 aborted = true;
1088 goto out_complete;
1089 } else
1090 goto out;
1091 }
1092
1093 /*
1094 * as long as no delay is required advance immediately
1095 * without scheduling a new work
1096 */
1097 do {
1098 if (!ieee80211_sdata_running(sdata)) {
1099 aborted = true;
1100 goto out_complete;
1101 }
1102
1103 switch (local->next_scan_state) {
1104 case SCAN_DECISION:
1105 /* if no more bands/channels left, complete scan */
1106 if (local->scan_channel_idx >= scan_req->n_channels) {
1107 aborted = false;
1108 goto out_complete;
1109 }
1110 ieee80211_scan_state_decision(local, &next_delay);
1111 break;
1112 case SCAN_SET_CHANNEL:
1113 ieee80211_scan_state_set_channel(local, &next_delay);
1114 break;
1115 case SCAN_SEND_PROBE:
1116 ieee80211_scan_state_send_probe(local, &next_delay);
1117 break;
1118 case SCAN_SUSPEND:
1119 ieee80211_scan_state_suspend(local, &next_delay);
1120 break;
1121 case SCAN_RESUME:
1122 ieee80211_scan_state_resume(local, &next_delay);
1123 break;
1124 case SCAN_ABORT:
1125 aborted = true;
1126 goto out_complete;
1127 }
1128 } while (next_delay == 0);
1129
1130 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
1131 goto out;
1132
1133 out_complete:
1134 __ieee80211_scan_completed(&local->hw, aborted);
1135 out:
1136 mutex_unlock(&local->mtx);
1137 }
1138
ieee80211_request_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)1139 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1140 struct cfg80211_scan_request *req)
1141 {
1142 int res;
1143
1144 mutex_lock(&sdata->local->mtx);
1145 res = __ieee80211_start_scan(sdata, req);
1146 mutex_unlock(&sdata->local->mtx);
1147
1148 return res;
1149 }
1150
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)1151 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1152 const u8 *ssid, u8 ssid_len,
1153 struct ieee80211_channel **channels,
1154 unsigned int n_channels,
1155 enum nl80211_bss_scan_width scan_width)
1156 {
1157 struct ieee80211_local *local = sdata->local;
1158 int ret = -EBUSY, i, n_ch = 0;
1159 enum nl80211_band band;
1160
1161 mutex_lock(&local->mtx);
1162
1163 /* busy scanning */
1164 if (local->scan_req)
1165 goto unlock;
1166
1167 /* fill internal scan request */
1168 if (!channels) {
1169 int max_n;
1170
1171 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1172 if (!local->hw.wiphy->bands[band] ||
1173 band == NL80211_BAND_6GHZ)
1174 continue;
1175
1176 max_n = local->hw.wiphy->bands[band]->n_channels;
1177 for (i = 0; i < max_n; i++) {
1178 struct ieee80211_channel *tmp_ch =
1179 &local->hw.wiphy->bands[band]->channels[i];
1180
1181 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1182 IEEE80211_CHAN_DISABLED))
1183 continue;
1184
1185 local->int_scan_req->channels[n_ch] = tmp_ch;
1186 n_ch++;
1187 }
1188 }
1189
1190 if (WARN_ON_ONCE(n_ch == 0))
1191 goto unlock;
1192
1193 local->int_scan_req->n_channels = n_ch;
1194 } else {
1195 for (i = 0; i < n_channels; i++) {
1196 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1197 IEEE80211_CHAN_DISABLED))
1198 continue;
1199
1200 local->int_scan_req->channels[n_ch] = channels[i];
1201 n_ch++;
1202 }
1203
1204 if (WARN_ON_ONCE(n_ch == 0))
1205 goto unlock;
1206
1207 local->int_scan_req->n_channels = n_ch;
1208 }
1209
1210 local->int_scan_req->ssids = &local->scan_ssid;
1211 local->int_scan_req->n_ssids = 1;
1212 local->int_scan_req->scan_width = scan_width;
1213 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1214 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1215
1216 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1217 unlock:
1218 mutex_unlock(&local->mtx);
1219 return ret;
1220 }
1221
1222 /*
1223 * Only call this function when a scan can't be queued -- under RTNL.
1224 */
ieee80211_scan_cancel(struct ieee80211_local * local)1225 void ieee80211_scan_cancel(struct ieee80211_local *local)
1226 {
1227 /*
1228 * We are canceling software scan, or deferred scan that was not
1229 * yet really started (see __ieee80211_start_scan ).
1230 *
1231 * Regarding hardware scan:
1232 * - we can not call __ieee80211_scan_completed() as when
1233 * SCAN_HW_SCANNING bit is set this function change
1234 * local->hw_scan_req to operate on 5G band, what race with
1235 * driver which can use local->hw_scan_req
1236 *
1237 * - we can not cancel scan_work since driver can schedule it
1238 * by ieee80211_scan_completed(..., true) to finish scan
1239 *
1240 * Hence we only call the cancel_hw_scan() callback, but the low-level
1241 * driver is still responsible for calling ieee80211_scan_completed()
1242 * after the scan was completed/aborted.
1243 */
1244
1245 mutex_lock(&local->mtx);
1246 if (!local->scan_req)
1247 goto out;
1248
1249 /*
1250 * We have a scan running and the driver already reported completion,
1251 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1252 * cancelled.
1253 */
1254 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1255 test_bit(SCAN_COMPLETED, &local->scanning)) {
1256 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1257 goto out;
1258 }
1259
1260 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1261 /*
1262 * Make sure that __ieee80211_scan_completed doesn't trigger a
1263 * scan on another band.
1264 */
1265 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1266 if (local->ops->cancel_hw_scan)
1267 drv_cancel_hw_scan(local,
1268 rcu_dereference_protected(local->scan_sdata,
1269 lockdep_is_held(&local->mtx)));
1270 goto out;
1271 }
1272
1273 /*
1274 * If the work is currently running, it must be blocked on
1275 * the mutex, but we'll set scan_sdata = NULL and it'll
1276 * simply exit once it acquires the mutex.
1277 */
1278 cancel_delayed_work(&local->scan_work);
1279 /* and clean up */
1280 memset(&local->scan_info, 0, sizeof(local->scan_info));
1281 __ieee80211_scan_completed(&local->hw, true);
1282 out:
1283 mutex_unlock(&local->mtx);
1284 }
1285
__ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1286 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1287 struct cfg80211_sched_scan_request *req)
1288 {
1289 struct ieee80211_local *local = sdata->local;
1290 struct ieee80211_scan_ies sched_scan_ies = {};
1291 struct cfg80211_chan_def chandef;
1292 int ret, i, iebufsz, num_bands = 0;
1293 u32 rate_masks[NUM_NL80211_BANDS] = {};
1294 u8 bands_used = 0;
1295 u8 *ie;
1296 u32 flags = 0;
1297
1298 iebufsz = local->scan_ies_len + req->ie_len;
1299
1300 lockdep_assert_held(&local->mtx);
1301
1302 if (!local->ops->sched_scan_start)
1303 return -ENOTSUPP;
1304
1305 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1306 if (local->hw.wiphy->bands[i]) {
1307 bands_used |= BIT(i);
1308 rate_masks[i] = (u32) -1;
1309 num_bands++;
1310 }
1311 }
1312
1313 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1314 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1315
1316 ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1317 if (!ie) {
1318 ret = -ENOMEM;
1319 goto out;
1320 }
1321
1322 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1323
1324 ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1325 &sched_scan_ies, req->ie,
1326 req->ie_len, bands_used, rate_masks, &chandef,
1327 flags);
1328
1329 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1330 if (ret == 0) {
1331 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1332 rcu_assign_pointer(local->sched_scan_req, req);
1333 }
1334
1335 kfree(ie);
1336
1337 out:
1338 if (ret) {
1339 /* Clean in case of failure after HW restart or upon resume. */
1340 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1341 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1342 }
1343
1344 return ret;
1345 }
1346
ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1347 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1348 struct cfg80211_sched_scan_request *req)
1349 {
1350 struct ieee80211_local *local = sdata->local;
1351 int ret;
1352
1353 mutex_lock(&local->mtx);
1354
1355 if (rcu_access_pointer(local->sched_scan_sdata)) {
1356 mutex_unlock(&local->mtx);
1357 return -EBUSY;
1358 }
1359
1360 ret = __ieee80211_request_sched_scan_start(sdata, req);
1361
1362 mutex_unlock(&local->mtx);
1363 return ret;
1364 }
1365
ieee80211_request_sched_scan_stop(struct ieee80211_local * local)1366 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1367 {
1368 struct ieee80211_sub_if_data *sched_scan_sdata;
1369 int ret = -ENOENT;
1370
1371 mutex_lock(&local->mtx);
1372
1373 if (!local->ops->sched_scan_stop) {
1374 ret = -ENOTSUPP;
1375 goto out;
1376 }
1377
1378 /* We don't want to restart sched scan anymore. */
1379 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1380
1381 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1382 lockdep_is_held(&local->mtx));
1383 if (sched_scan_sdata) {
1384 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1385 if (!ret)
1386 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1387 }
1388 out:
1389 mutex_unlock(&local->mtx);
1390
1391 return ret;
1392 }
1393
ieee80211_sched_scan_results(struct ieee80211_hw * hw)1394 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1395 {
1396 struct ieee80211_local *local = hw_to_local(hw);
1397
1398 trace_api_sched_scan_results(local);
1399
1400 cfg80211_sched_scan_results(hw->wiphy, 0);
1401 }
1402 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1403
ieee80211_sched_scan_end(struct ieee80211_local * local)1404 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1405 {
1406 mutex_lock(&local->mtx);
1407
1408 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1409 mutex_unlock(&local->mtx);
1410 return;
1411 }
1412
1413 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1414
1415 /* If sched scan was aborted by the driver. */
1416 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1417
1418 mutex_unlock(&local->mtx);
1419
1420 cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1421 }
1422
ieee80211_sched_scan_stopped_work(struct work_struct * work)1423 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1424 {
1425 struct ieee80211_local *local =
1426 container_of(work, struct ieee80211_local,
1427 sched_scan_stopped_work);
1428
1429 ieee80211_sched_scan_end(local);
1430 }
1431
ieee80211_sched_scan_stopped(struct ieee80211_hw * hw)1432 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1433 {
1434 struct ieee80211_local *local = hw_to_local(hw);
1435
1436 trace_api_sched_scan_stopped(local);
1437
1438 /*
1439 * this shouldn't really happen, so for simplicity
1440 * simply ignore it, and let mac80211 reconfigure
1441 * the sched scan later on.
1442 */
1443 if (local->in_reconfig)
1444 return;
1445
1446 schedule_work(&local->sched_scan_stopped_work);
1447 }
1448 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
1449