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 size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
255 u.probe_resp.variable);
256
257 if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
258 !ieee80211_is_beacon(mgmt->frame_control) &&
259 !ieee80211_is_s1g_beacon(mgmt->frame_control))
260 return;
261
262 if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
263 if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
264 min_hdr_len = offsetof(struct ieee80211_ext,
265 u.s1g_short_beacon.variable);
266 else
267 min_hdr_len = offsetof(struct ieee80211_ext,
268 u.s1g_beacon);
269 }
270
271 if (skb->len < min_hdr_len)
272 return;
273
274 sdata1 = rcu_dereference(local->scan_sdata);
275 sdata2 = rcu_dereference(local->sched_scan_sdata);
276
277 if (likely(!sdata1 && !sdata2))
278 return;
279
280 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
281 struct cfg80211_scan_request *scan_req;
282 struct cfg80211_sched_scan_request *sched_scan_req;
283 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
284
285 scan_req = rcu_dereference(local->scan_req);
286 sched_scan_req = rcu_dereference(local->sched_scan_req);
287
288 if (scan_req)
289 scan_req_flags = scan_req->flags;
290
291 if (sched_scan_req)
292 sched_scan_req_flags = sched_scan_req->flags;
293
294 /* ignore ProbeResp to foreign address or non-bcast (OCE)
295 * unless scanning with randomised address
296 */
297 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
298 mgmt->da) &&
299 !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
300 mgmt->da))
301 return;
302 }
303
304 channel = ieee80211_get_channel_khz(local->hw.wiphy,
305 ieee80211_rx_status_to_khz(rx_status));
306
307 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
308 return;
309
310 bss = ieee80211_bss_info_update(local, rx_status,
311 mgmt, skb->len,
312 channel);
313 if (bss)
314 ieee80211_rx_bss_put(local, bss);
315 }
316
317 static void
ieee80211_prepare_scan_chandef(struct cfg80211_chan_def * chandef,enum nl80211_bss_scan_width scan_width)318 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
319 enum nl80211_bss_scan_width scan_width)
320 {
321 memset(chandef, 0, sizeof(*chandef));
322 switch (scan_width) {
323 case NL80211_BSS_CHAN_WIDTH_5:
324 chandef->width = NL80211_CHAN_WIDTH_5;
325 break;
326 case NL80211_BSS_CHAN_WIDTH_10:
327 chandef->width = NL80211_CHAN_WIDTH_10;
328 break;
329 default:
330 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
331 break;
332 }
333 }
334
335 /* return false if no more work */
ieee80211_prep_hw_scan(struct ieee80211_sub_if_data * sdata)336 static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
337 {
338 struct ieee80211_local *local = sdata->local;
339 struct cfg80211_scan_request *req;
340 struct cfg80211_chan_def chandef;
341 u8 bands_used = 0;
342 int i, ielen, n_chans;
343 u32 flags = 0;
344
345 req = rcu_dereference_protected(local->scan_req,
346 lockdep_is_held(&local->mtx));
347
348 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
349 return false;
350
351 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
352 for (i = 0; i < req->n_channels; i++) {
353 local->hw_scan_req->req.channels[i] = req->channels[i];
354 bands_used |= BIT(req->channels[i]->band);
355 }
356
357 n_chans = req->n_channels;
358 } else {
359 do {
360 if (local->hw_scan_band == NUM_NL80211_BANDS)
361 return false;
362
363 n_chans = 0;
364
365 for (i = 0; i < req->n_channels; i++) {
366 if (req->channels[i]->band !=
367 local->hw_scan_band)
368 continue;
369 local->hw_scan_req->req.channels[n_chans] =
370 req->channels[i];
371 n_chans++;
372 bands_used |= BIT(req->channels[i]->band);
373 }
374
375 local->hw_scan_band++;
376 } while (!n_chans);
377 }
378
379 local->hw_scan_req->req.n_channels = n_chans;
380 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
381
382 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
383 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
384
385 ielen = ieee80211_build_preq_ies(sdata,
386 (u8 *)local->hw_scan_req->req.ie,
387 local->hw_scan_ies_bufsize,
388 &local->hw_scan_req->ies,
389 req->ie, req->ie_len,
390 bands_used, req->rates, &chandef,
391 flags);
392 local->hw_scan_req->req.ie_len = ielen;
393 local->hw_scan_req->req.no_cck = req->no_cck;
394 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
395 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
396 req->mac_addr_mask);
397 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
398
399 return true;
400 }
401
__ieee80211_scan_completed(struct ieee80211_hw * hw,bool aborted)402 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
403 {
404 struct ieee80211_local *local = hw_to_local(hw);
405 bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
406 bool was_scanning = local->scanning;
407 struct cfg80211_scan_request *scan_req;
408 struct ieee80211_sub_if_data *scan_sdata;
409 struct ieee80211_sub_if_data *sdata;
410
411 lockdep_assert_held(&local->mtx);
412
413 /*
414 * It's ok to abort a not-yet-running scan (that
415 * we have one at all will be verified by checking
416 * local->scan_req next), but not to complete it
417 * successfully.
418 */
419 if (WARN_ON(!local->scanning && !aborted))
420 aborted = true;
421
422 if (WARN_ON(!local->scan_req))
423 return;
424
425 scan_sdata = rcu_dereference_protected(local->scan_sdata,
426 lockdep_is_held(&local->mtx));
427
428 if (hw_scan && !aborted &&
429 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
430 ieee80211_prep_hw_scan(scan_sdata)) {
431 int rc;
432
433 rc = drv_hw_scan(local,
434 rcu_dereference_protected(local->scan_sdata,
435 lockdep_is_held(&local->mtx)),
436 local->hw_scan_req);
437
438 if (rc == 0)
439 return;
440
441 /* HW scan failed and is going to be reported as aborted,
442 * so clear old scan info.
443 */
444 memset(&local->scan_info, 0, sizeof(local->scan_info));
445 aborted = true;
446 }
447
448 kfree(local->hw_scan_req);
449 local->hw_scan_req = NULL;
450
451 scan_req = rcu_dereference_protected(local->scan_req,
452 lockdep_is_held(&local->mtx));
453
454 if (scan_req != local->int_scan_req) {
455 local->scan_info.aborted = aborted;
456 cfg80211_scan_done(scan_req, &local->scan_info);
457 }
458 RCU_INIT_POINTER(local->scan_req, NULL);
459 RCU_INIT_POINTER(local->scan_sdata, NULL);
460
461 local->scanning = 0;
462 local->scan_chandef.chan = NULL;
463
464 /* Set power back to normal operating levels. */
465 ieee80211_hw_config(local, 0);
466
467 if (!hw_scan) {
468 ieee80211_configure_filter(local);
469 drv_sw_scan_complete(local, scan_sdata);
470 ieee80211_offchannel_return(local);
471 }
472
473 ieee80211_recalc_idle(local);
474
475 ieee80211_mlme_notify_scan_completed(local);
476 ieee80211_ibss_notify_scan_completed(local);
477
478 /* Requeue all the work that might have been ignored while
479 * the scan was in progress; if there was none this will
480 * just be a no-op for the particular interface.
481 */
482 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
483 if (ieee80211_sdata_running(sdata))
484 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
485 }
486
487 if (was_scanning)
488 ieee80211_start_next_roc(local);
489 }
490
ieee80211_scan_completed(struct ieee80211_hw * hw,struct cfg80211_scan_info * info)491 void ieee80211_scan_completed(struct ieee80211_hw *hw,
492 struct cfg80211_scan_info *info)
493 {
494 struct ieee80211_local *local = hw_to_local(hw);
495
496 trace_api_scan_completed(local, info->aborted);
497
498 set_bit(SCAN_COMPLETED, &local->scanning);
499 if (info->aborted)
500 set_bit(SCAN_ABORTED, &local->scanning);
501
502 memcpy(&local->scan_info, info, sizeof(*info));
503
504 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
505 }
506 EXPORT_SYMBOL(ieee80211_scan_completed);
507
ieee80211_start_sw_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)508 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
509 struct ieee80211_sub_if_data *sdata)
510 {
511 /* Software scan is not supported in multi-channel cases */
512 if (local->use_chanctx)
513 return -EOPNOTSUPP;
514
515 /*
516 * Hardware/driver doesn't support hw_scan, so use software
517 * scanning instead. First send a nullfunc frame with power save
518 * bit on so that AP will buffer the frames for us while we are not
519 * listening, then send probe requests to each channel and wait for
520 * the responses. After all channels are scanned, tune back to the
521 * original channel and send a nullfunc frame with power save bit
522 * off to trigger the AP to send us all the buffered frames.
523 *
524 * Note that while local->sw_scanning is true everything else but
525 * nullfunc frames and probe requests will be dropped in
526 * ieee80211_tx_h_check_assoc().
527 */
528 drv_sw_scan_start(local, sdata, local->scan_addr);
529
530 local->leave_oper_channel_time = jiffies;
531 local->next_scan_state = SCAN_DECISION;
532 local->scan_channel_idx = 0;
533
534 ieee80211_offchannel_stop_vifs(local);
535
536 /* ensure nullfunc is transmitted before leaving operating channel */
537 ieee80211_flush_queues(local, NULL, false);
538
539 ieee80211_configure_filter(local);
540
541 /* We need to set power level at maximum rate for scanning. */
542 ieee80211_hw_config(local, 0);
543
544 ieee80211_queue_delayed_work(&local->hw,
545 &local->scan_work, 0);
546
547 return 0;
548 }
549
__ieee80211_can_leave_ch(struct ieee80211_sub_if_data * sdata)550 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
551 {
552 struct ieee80211_local *local = sdata->local;
553 struct ieee80211_sub_if_data *sdata_iter;
554
555 if (!ieee80211_is_radar_required(local))
556 return true;
557
558 if (!regulatory_pre_cac_allowed(local->hw.wiphy))
559 return false;
560
561 mutex_lock(&local->iflist_mtx);
562 list_for_each_entry(sdata_iter, &local->interfaces, list) {
563 if (sdata_iter->wdev.cac_started) {
564 mutex_unlock(&local->iflist_mtx);
565 return false;
566 }
567 }
568 mutex_unlock(&local->iflist_mtx);
569
570 return true;
571 }
572
ieee80211_can_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)573 static bool ieee80211_can_scan(struct ieee80211_local *local,
574 struct ieee80211_sub_if_data *sdata)
575 {
576 if (!__ieee80211_can_leave_ch(sdata))
577 return false;
578
579 if (!list_empty(&local->roc_list))
580 return false;
581
582 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
583 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
584 return false;
585
586 return true;
587 }
588
ieee80211_run_deferred_scan(struct ieee80211_local * local)589 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
590 {
591 lockdep_assert_held(&local->mtx);
592
593 if (!local->scan_req || local->scanning)
594 return;
595
596 if (!ieee80211_can_scan(local,
597 rcu_dereference_protected(
598 local->scan_sdata,
599 lockdep_is_held(&local->mtx))))
600 return;
601
602 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
603 round_jiffies_relative(0));
604 }
605
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)606 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
607 const u8 *src, const u8 *dst,
608 const u8 *ssid, size_t ssid_len,
609 const u8 *ie, size_t ie_len,
610 u32 ratemask, u32 flags, u32 tx_flags,
611 struct ieee80211_channel *channel)
612 {
613 struct sk_buff *skb;
614
615 skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
616 ssid, ssid_len,
617 ie, ie_len, flags);
618
619 if (skb) {
620 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
621 struct ieee80211_hdr *hdr = (void *)skb->data;
622 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
623 u16 sn = get_random_u32();
624
625 info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
626 hdr->seq_ctrl =
627 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
628 }
629 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
630 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
631 }
632 }
633
ieee80211_scan_state_send_probe(struct ieee80211_local * local,unsigned long * next_delay)634 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
635 unsigned long *next_delay)
636 {
637 int i;
638 struct ieee80211_sub_if_data *sdata;
639 struct cfg80211_scan_request *scan_req;
640 enum nl80211_band band = local->hw.conf.chandef.chan->band;
641 u32 flags = 0, tx_flags;
642
643 scan_req = rcu_dereference_protected(local->scan_req,
644 lockdep_is_held(&local->mtx));
645
646 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
647 if (scan_req->no_cck)
648 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
649 if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
650 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
651 if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
652 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
653
654 sdata = rcu_dereference_protected(local->scan_sdata,
655 lockdep_is_held(&local->mtx));
656
657 for (i = 0; i < scan_req->n_ssids; i++)
658 ieee80211_send_scan_probe_req(
659 sdata, local->scan_addr, scan_req->bssid,
660 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
661 scan_req->ie, scan_req->ie_len,
662 scan_req->rates[band], flags,
663 tx_flags, local->hw.conf.chandef.chan);
664
665 /*
666 * After sending probe requests, wait for probe responses
667 * on the channel.
668 */
669 *next_delay = IEEE80211_CHANNEL_TIME;
670 local->next_scan_state = SCAN_DECISION;
671 }
672
__ieee80211_start_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)673 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
674 struct cfg80211_scan_request *req)
675 {
676 struct ieee80211_local *local = sdata->local;
677 bool hw_scan = local->ops->hw_scan;
678 int rc;
679
680 lockdep_assert_held(&local->mtx);
681
682 if (local->scan_req)
683 return -EBUSY;
684
685 if (!__ieee80211_can_leave_ch(sdata))
686 return -EBUSY;
687
688 if (!ieee80211_can_scan(local, sdata)) {
689 /* wait for the work to finish/time out */
690 rcu_assign_pointer(local->scan_req, req);
691 rcu_assign_pointer(local->scan_sdata, sdata);
692 return 0;
693 }
694
695 again:
696 if (hw_scan) {
697 u8 *ies;
698
699 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
700
701 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
702 int i, n_bands = 0;
703 u8 bands_counted = 0;
704
705 for (i = 0; i < req->n_channels; i++) {
706 if (bands_counted & BIT(req->channels[i]->band))
707 continue;
708 bands_counted |= BIT(req->channels[i]->band);
709 n_bands++;
710 }
711
712 local->hw_scan_ies_bufsize *= n_bands;
713 }
714
715 local->hw_scan_req = kmalloc(
716 sizeof(*local->hw_scan_req) +
717 req->n_channels * sizeof(req->channels[0]) +
718 local->hw_scan_ies_bufsize, GFP_KERNEL);
719 if (!local->hw_scan_req)
720 return -ENOMEM;
721
722 local->hw_scan_req->req.ssids = req->ssids;
723 local->hw_scan_req->req.n_ssids = req->n_ssids;
724 ies = (u8 *)local->hw_scan_req +
725 sizeof(*local->hw_scan_req) +
726 req->n_channels * sizeof(req->channels[0]);
727 local->hw_scan_req->req.ie = ies;
728 local->hw_scan_req->req.flags = req->flags;
729 eth_broadcast_addr(local->hw_scan_req->req.bssid);
730 local->hw_scan_req->req.duration = req->duration;
731 local->hw_scan_req->req.duration_mandatory =
732 req->duration_mandatory;
733
734 local->hw_scan_band = 0;
735 local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
736 local->hw_scan_req->req.scan_6ghz_params =
737 req->scan_6ghz_params;
738 local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
739
740 /*
741 * After allocating local->hw_scan_req, we must
742 * go through until ieee80211_prep_hw_scan(), so
743 * anything that might be changed here and leave
744 * this function early must not go after this
745 * allocation.
746 */
747 }
748
749 rcu_assign_pointer(local->scan_req, req);
750 rcu_assign_pointer(local->scan_sdata, sdata);
751
752 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
753 get_random_mask_addr(local->scan_addr,
754 req->mac_addr,
755 req->mac_addr_mask);
756 else
757 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
758
759 if (hw_scan) {
760 __set_bit(SCAN_HW_SCANNING, &local->scanning);
761 } else if ((req->n_channels == 1) &&
762 (req->channels[0] == local->_oper_chandef.chan)) {
763 /*
764 * If we are scanning only on the operating channel
765 * then we do not need to stop normal activities
766 */
767 unsigned long next_delay;
768
769 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
770
771 ieee80211_recalc_idle(local);
772
773 /* Notify driver scan is starting, keep order of operations
774 * same as normal software scan, in case that matters. */
775 drv_sw_scan_start(local, sdata, local->scan_addr);
776
777 ieee80211_configure_filter(local); /* accept probe-responses */
778
779 /* We need to ensure power level is at max for scanning. */
780 ieee80211_hw_config(local, 0);
781
782 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
783 IEEE80211_CHAN_RADAR)) ||
784 !req->n_ssids) {
785 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
786 } else {
787 ieee80211_scan_state_send_probe(local, &next_delay);
788 next_delay = IEEE80211_CHANNEL_TIME;
789 }
790
791 /* Now, just wait a bit and we are all done! */
792 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
793 next_delay);
794 return 0;
795 } else {
796 /* Do normal software scan */
797 __set_bit(SCAN_SW_SCANNING, &local->scanning);
798 }
799
800 ieee80211_recalc_idle(local);
801
802 if (hw_scan) {
803 WARN_ON(!ieee80211_prep_hw_scan(sdata));
804 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
805 } else {
806 rc = ieee80211_start_sw_scan(local, sdata);
807 }
808
809 if (rc) {
810 kfree(local->hw_scan_req);
811 local->hw_scan_req = NULL;
812 local->scanning = 0;
813
814 ieee80211_recalc_idle(local);
815
816 local->scan_req = NULL;
817 RCU_INIT_POINTER(local->scan_sdata, NULL);
818 }
819
820 if (hw_scan && rc == 1) {
821 /*
822 * we can't fall back to software for P2P-GO
823 * as it must update NoA etc.
824 */
825 if (ieee80211_vif_type_p2p(&sdata->vif) ==
826 NL80211_IFTYPE_P2P_GO)
827 return -EOPNOTSUPP;
828 hw_scan = false;
829 goto again;
830 }
831
832 return rc;
833 }
834
835 static unsigned long
ieee80211_scan_get_channel_time(struct ieee80211_channel * chan)836 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
837 {
838 /*
839 * TODO: channel switching also consumes quite some time,
840 * add that delay as well to get a better estimation
841 */
842 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
843 return IEEE80211_PASSIVE_CHANNEL_TIME;
844 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
845 }
846
ieee80211_scan_state_decision(struct ieee80211_local * local,unsigned long * next_delay)847 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
848 unsigned long *next_delay)
849 {
850 bool associated = false;
851 bool tx_empty = true;
852 bool bad_latency;
853 struct ieee80211_sub_if_data *sdata;
854 struct ieee80211_channel *next_chan;
855 enum mac80211_scan_state next_scan_state;
856 struct cfg80211_scan_request *scan_req;
857
858 /*
859 * check if at least one STA interface is associated,
860 * check if at least one STA interface has pending tx frames
861 * and grab the lowest used beacon interval
862 */
863 mutex_lock(&local->iflist_mtx);
864 list_for_each_entry(sdata, &local->interfaces, list) {
865 if (!ieee80211_sdata_running(sdata))
866 continue;
867
868 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
869 if (sdata->u.mgd.associated) {
870 associated = true;
871
872 if (!qdisc_all_tx_empty(sdata->dev)) {
873 tx_empty = false;
874 break;
875 }
876 }
877 }
878 }
879 mutex_unlock(&local->iflist_mtx);
880
881 scan_req = rcu_dereference_protected(local->scan_req,
882 lockdep_is_held(&local->mtx));
883
884 next_chan = scan_req->channels[local->scan_channel_idx];
885
886 /*
887 * we're currently scanning a different channel, let's
888 * see if we can scan another channel without interfering
889 * with the current traffic situation.
890 *
891 * Keep good latency, do not stay off-channel more than 125 ms.
892 */
893
894 bad_latency = time_after(jiffies +
895 ieee80211_scan_get_channel_time(next_chan),
896 local->leave_oper_channel_time + HZ / 8);
897
898 if (associated && !tx_empty) {
899 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
900 next_scan_state = SCAN_ABORT;
901 else
902 next_scan_state = SCAN_SUSPEND;
903 } else if (associated && bad_latency) {
904 next_scan_state = SCAN_SUSPEND;
905 } else {
906 next_scan_state = SCAN_SET_CHANNEL;
907 }
908
909 local->next_scan_state = next_scan_state;
910
911 *next_delay = 0;
912 }
913
ieee80211_scan_state_set_channel(struct ieee80211_local * local,unsigned long * next_delay)914 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
915 unsigned long *next_delay)
916 {
917 int skip;
918 struct ieee80211_channel *chan;
919 enum nl80211_bss_scan_width oper_scan_width;
920 struct cfg80211_scan_request *scan_req;
921
922 scan_req = rcu_dereference_protected(local->scan_req,
923 lockdep_is_held(&local->mtx));
924
925 skip = 0;
926 chan = scan_req->channels[local->scan_channel_idx];
927
928 local->scan_chandef.chan = chan;
929 local->scan_chandef.center_freq1 = chan->center_freq;
930 local->scan_chandef.freq1_offset = chan->freq_offset;
931 local->scan_chandef.center_freq2 = 0;
932
933 /* For scanning on the S1G band, ignore scan_width (which is constant
934 * across all channels) for now since channel width is specific to each
935 * channel. Detect the required channel width here and likely revisit
936 * later. Maybe scan_width could be used to build the channel scan list?
937 */
938 if (chan->band == NL80211_BAND_S1GHZ) {
939 local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
940 goto set_channel;
941 }
942
943 switch (scan_req->scan_width) {
944 case NL80211_BSS_CHAN_WIDTH_5:
945 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
946 break;
947 case NL80211_BSS_CHAN_WIDTH_10:
948 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
949 break;
950 default:
951 case NL80211_BSS_CHAN_WIDTH_20:
952 /* If scanning on oper channel, use whatever channel-type
953 * is currently in use.
954 */
955 oper_scan_width = cfg80211_chandef_to_scan_width(
956 &local->_oper_chandef);
957 if (chan == local->_oper_chandef.chan &&
958 oper_scan_width == scan_req->scan_width)
959 local->scan_chandef = local->_oper_chandef;
960 else
961 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
962 break;
963 case NL80211_BSS_CHAN_WIDTH_1:
964 case NL80211_BSS_CHAN_WIDTH_2:
965 /* shouldn't get here, S1G handled above */
966 WARN_ON(1);
967 break;
968 }
969
970 set_channel:
971 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
972 skip = 1;
973
974 /* advance state machine to next channel/band */
975 local->scan_channel_idx++;
976
977 if (skip) {
978 /* if we skip this channel return to the decision state */
979 local->next_scan_state = SCAN_DECISION;
980 return;
981 }
982
983 /*
984 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
985 * (which unfortunately doesn't say _why_ step a) is done,
986 * but it waits for the probe delay or until a frame is
987 * received - and the received frame would update the NAV).
988 * For now, we do not support waiting until a frame is
989 * received.
990 *
991 * In any case, it is not necessary for a passive scan.
992 */
993 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
994 !scan_req->n_ssids) {
995 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
996 local->next_scan_state = SCAN_DECISION;
997 return;
998 }
999
1000 /* active scan, send probes */
1001 *next_delay = IEEE80211_PROBE_DELAY;
1002 local->next_scan_state = SCAN_SEND_PROBE;
1003 }
1004
ieee80211_scan_state_suspend(struct ieee80211_local * local,unsigned long * next_delay)1005 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1006 unsigned long *next_delay)
1007 {
1008 /* switch back to the operating channel */
1009 local->scan_chandef.chan = NULL;
1010 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
1011
1012 /* disable PS */
1013 ieee80211_offchannel_return(local);
1014
1015 *next_delay = HZ / 5;
1016 /* afterwards, resume scan & go to next channel */
1017 local->next_scan_state = SCAN_RESUME;
1018 }
1019
ieee80211_scan_state_resume(struct ieee80211_local * local,unsigned long * next_delay)1020 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1021 unsigned long *next_delay)
1022 {
1023 ieee80211_offchannel_stop_vifs(local);
1024
1025 if (local->ops->flush) {
1026 ieee80211_flush_queues(local, NULL, false);
1027 *next_delay = 0;
1028 } else
1029 *next_delay = HZ / 10;
1030
1031 /* remember when we left the operating channel */
1032 local->leave_oper_channel_time = jiffies;
1033
1034 /* advance to the next channel to be scanned */
1035 local->next_scan_state = SCAN_SET_CHANNEL;
1036 }
1037
ieee80211_scan_work(struct work_struct * work)1038 void ieee80211_scan_work(struct work_struct *work)
1039 {
1040 struct ieee80211_local *local =
1041 container_of(work, struct ieee80211_local, scan_work.work);
1042 struct ieee80211_sub_if_data *sdata;
1043 struct cfg80211_scan_request *scan_req;
1044 unsigned long next_delay = 0;
1045 bool aborted;
1046
1047 mutex_lock(&local->mtx);
1048
1049 if (!ieee80211_can_run_worker(local)) {
1050 aborted = true;
1051 goto out_complete;
1052 }
1053
1054 sdata = rcu_dereference_protected(local->scan_sdata,
1055 lockdep_is_held(&local->mtx));
1056 scan_req = rcu_dereference_protected(local->scan_req,
1057 lockdep_is_held(&local->mtx));
1058
1059 /* When scanning on-channel, the first-callback means completed. */
1060 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1061 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1062 goto out_complete;
1063 }
1064
1065 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1066 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1067 goto out_complete;
1068 }
1069
1070 if (!sdata || !scan_req)
1071 goto out;
1072
1073 if (!local->scanning) {
1074 int rc;
1075
1076 RCU_INIT_POINTER(local->scan_req, NULL);
1077 RCU_INIT_POINTER(local->scan_sdata, NULL);
1078
1079 rc = __ieee80211_start_scan(sdata, scan_req);
1080 if (rc) {
1081 /* need to complete scan in cfg80211 */
1082 rcu_assign_pointer(local->scan_req, scan_req);
1083 aborted = true;
1084 goto out_complete;
1085 } else
1086 goto out;
1087 }
1088
1089 /*
1090 * as long as no delay is required advance immediately
1091 * without scheduling a new work
1092 */
1093 do {
1094 if (!ieee80211_sdata_running(sdata)) {
1095 aborted = true;
1096 goto out_complete;
1097 }
1098
1099 switch (local->next_scan_state) {
1100 case SCAN_DECISION:
1101 /* if no more bands/channels left, complete scan */
1102 if (local->scan_channel_idx >= scan_req->n_channels) {
1103 aborted = false;
1104 goto out_complete;
1105 }
1106 ieee80211_scan_state_decision(local, &next_delay);
1107 break;
1108 case SCAN_SET_CHANNEL:
1109 ieee80211_scan_state_set_channel(local, &next_delay);
1110 break;
1111 case SCAN_SEND_PROBE:
1112 ieee80211_scan_state_send_probe(local, &next_delay);
1113 break;
1114 case SCAN_SUSPEND:
1115 ieee80211_scan_state_suspend(local, &next_delay);
1116 break;
1117 case SCAN_RESUME:
1118 ieee80211_scan_state_resume(local, &next_delay);
1119 break;
1120 case SCAN_ABORT:
1121 aborted = true;
1122 goto out_complete;
1123 }
1124 } while (next_delay == 0);
1125
1126 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
1127 goto out;
1128
1129 out_complete:
1130 __ieee80211_scan_completed(&local->hw, aborted);
1131 out:
1132 mutex_unlock(&local->mtx);
1133 }
1134
ieee80211_request_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)1135 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1136 struct cfg80211_scan_request *req)
1137 {
1138 int res;
1139
1140 mutex_lock(&sdata->local->mtx);
1141 res = __ieee80211_start_scan(sdata, req);
1142 mutex_unlock(&sdata->local->mtx);
1143
1144 return res;
1145 }
1146
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)1147 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1148 const u8 *ssid, u8 ssid_len,
1149 struct ieee80211_channel **channels,
1150 unsigned int n_channels,
1151 enum nl80211_bss_scan_width scan_width)
1152 {
1153 struct ieee80211_local *local = sdata->local;
1154 int ret = -EBUSY, i, n_ch = 0;
1155 enum nl80211_band band;
1156
1157 mutex_lock(&local->mtx);
1158
1159 /* busy scanning */
1160 if (local->scan_req)
1161 goto unlock;
1162
1163 /* fill internal scan request */
1164 if (!channels) {
1165 int max_n;
1166
1167 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1168 if (!local->hw.wiphy->bands[band] ||
1169 band == NL80211_BAND_6GHZ)
1170 continue;
1171
1172 max_n = local->hw.wiphy->bands[band]->n_channels;
1173 for (i = 0; i < max_n; i++) {
1174 struct ieee80211_channel *tmp_ch =
1175 &local->hw.wiphy->bands[band]->channels[i];
1176
1177 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1178 IEEE80211_CHAN_DISABLED))
1179 continue;
1180
1181 local->int_scan_req->channels[n_ch] = tmp_ch;
1182 n_ch++;
1183 }
1184 }
1185
1186 if (WARN_ON_ONCE(n_ch == 0))
1187 goto unlock;
1188
1189 local->int_scan_req->n_channels = n_ch;
1190 } else {
1191 for (i = 0; i < n_channels; i++) {
1192 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1193 IEEE80211_CHAN_DISABLED))
1194 continue;
1195
1196 local->int_scan_req->channels[n_ch] = channels[i];
1197 n_ch++;
1198 }
1199
1200 if (WARN_ON_ONCE(n_ch == 0))
1201 goto unlock;
1202
1203 local->int_scan_req->n_channels = n_ch;
1204 }
1205
1206 local->int_scan_req->ssids = &local->scan_ssid;
1207 local->int_scan_req->n_ssids = 1;
1208 local->int_scan_req->scan_width = scan_width;
1209 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1210 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1211
1212 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1213 unlock:
1214 mutex_unlock(&local->mtx);
1215 return ret;
1216 }
1217
1218 /*
1219 * Only call this function when a scan can't be queued -- under RTNL.
1220 */
ieee80211_scan_cancel(struct ieee80211_local * local)1221 void ieee80211_scan_cancel(struct ieee80211_local *local)
1222 {
1223 /*
1224 * We are canceling software scan, or deferred scan that was not
1225 * yet really started (see __ieee80211_start_scan ).
1226 *
1227 * Regarding hardware scan:
1228 * - we can not call __ieee80211_scan_completed() as when
1229 * SCAN_HW_SCANNING bit is set this function change
1230 * local->hw_scan_req to operate on 5G band, what race with
1231 * driver which can use local->hw_scan_req
1232 *
1233 * - we can not cancel scan_work since driver can schedule it
1234 * by ieee80211_scan_completed(..., true) to finish scan
1235 *
1236 * Hence we only call the cancel_hw_scan() callback, but the low-level
1237 * driver is still responsible for calling ieee80211_scan_completed()
1238 * after the scan was completed/aborted.
1239 */
1240
1241 mutex_lock(&local->mtx);
1242 if (!local->scan_req)
1243 goto out;
1244
1245 /*
1246 * We have a scan running and the driver already reported completion,
1247 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1248 * cancelled.
1249 */
1250 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1251 test_bit(SCAN_COMPLETED, &local->scanning)) {
1252 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1253 goto out;
1254 }
1255
1256 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1257 /*
1258 * Make sure that __ieee80211_scan_completed doesn't trigger a
1259 * scan on another band.
1260 */
1261 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1262 if (local->ops->cancel_hw_scan)
1263 drv_cancel_hw_scan(local,
1264 rcu_dereference_protected(local->scan_sdata,
1265 lockdep_is_held(&local->mtx)));
1266 goto out;
1267 }
1268
1269 /*
1270 * If the work is currently running, it must be blocked on
1271 * the mutex, but we'll set scan_sdata = NULL and it'll
1272 * simply exit once it acquires the mutex.
1273 */
1274 cancel_delayed_work(&local->scan_work);
1275 /* and clean up */
1276 memset(&local->scan_info, 0, sizeof(local->scan_info));
1277 __ieee80211_scan_completed(&local->hw, true);
1278 out:
1279 mutex_unlock(&local->mtx);
1280 }
1281
__ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1282 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1283 struct cfg80211_sched_scan_request *req)
1284 {
1285 struct ieee80211_local *local = sdata->local;
1286 struct ieee80211_scan_ies sched_scan_ies = {};
1287 struct cfg80211_chan_def chandef;
1288 int ret, i, iebufsz, num_bands = 0;
1289 u32 rate_masks[NUM_NL80211_BANDS] = {};
1290 u8 bands_used = 0;
1291 u8 *ie;
1292 u32 flags = 0;
1293
1294 iebufsz = local->scan_ies_len + req->ie_len;
1295
1296 lockdep_assert_held(&local->mtx);
1297
1298 if (!local->ops->sched_scan_start)
1299 return -ENOTSUPP;
1300
1301 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1302 if (local->hw.wiphy->bands[i]) {
1303 bands_used |= BIT(i);
1304 rate_masks[i] = (u32) -1;
1305 num_bands++;
1306 }
1307 }
1308
1309 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1310 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1311
1312 ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1313 if (!ie) {
1314 ret = -ENOMEM;
1315 goto out;
1316 }
1317
1318 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1319
1320 ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1321 &sched_scan_ies, req->ie,
1322 req->ie_len, bands_used, rate_masks, &chandef,
1323 flags);
1324
1325 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1326 if (ret == 0) {
1327 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1328 rcu_assign_pointer(local->sched_scan_req, req);
1329 }
1330
1331 kfree(ie);
1332
1333 out:
1334 if (ret) {
1335 /* Clean in case of failure after HW restart or upon resume. */
1336 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1337 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1338 }
1339
1340 return ret;
1341 }
1342
ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1343 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1344 struct cfg80211_sched_scan_request *req)
1345 {
1346 struct ieee80211_local *local = sdata->local;
1347 int ret;
1348
1349 mutex_lock(&local->mtx);
1350
1351 if (rcu_access_pointer(local->sched_scan_sdata)) {
1352 mutex_unlock(&local->mtx);
1353 return -EBUSY;
1354 }
1355
1356 ret = __ieee80211_request_sched_scan_start(sdata, req);
1357
1358 mutex_unlock(&local->mtx);
1359 return ret;
1360 }
1361
ieee80211_request_sched_scan_stop(struct ieee80211_local * local)1362 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1363 {
1364 struct ieee80211_sub_if_data *sched_scan_sdata;
1365 int ret = -ENOENT;
1366
1367 mutex_lock(&local->mtx);
1368
1369 if (!local->ops->sched_scan_stop) {
1370 ret = -ENOTSUPP;
1371 goto out;
1372 }
1373
1374 /* We don't want to restart sched scan anymore. */
1375 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1376
1377 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1378 lockdep_is_held(&local->mtx));
1379 if (sched_scan_sdata) {
1380 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1381 if (!ret)
1382 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1383 }
1384 out:
1385 mutex_unlock(&local->mtx);
1386
1387 return ret;
1388 }
1389
ieee80211_sched_scan_results(struct ieee80211_hw * hw)1390 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1391 {
1392 struct ieee80211_local *local = hw_to_local(hw);
1393
1394 trace_api_sched_scan_results(local);
1395
1396 cfg80211_sched_scan_results(hw->wiphy, 0);
1397 }
1398 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1399
ieee80211_sched_scan_end(struct ieee80211_local * local)1400 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1401 {
1402 mutex_lock(&local->mtx);
1403
1404 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1405 mutex_unlock(&local->mtx);
1406 return;
1407 }
1408
1409 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1410
1411 /* If sched scan was aborted by the driver. */
1412 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1413
1414 mutex_unlock(&local->mtx);
1415
1416 cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1417 }
1418
ieee80211_sched_scan_stopped_work(struct work_struct * work)1419 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1420 {
1421 struct ieee80211_local *local =
1422 container_of(work, struct ieee80211_local,
1423 sched_scan_stopped_work);
1424
1425 ieee80211_sched_scan_end(local);
1426 }
1427
ieee80211_sched_scan_stopped(struct ieee80211_hw * hw)1428 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1429 {
1430 struct ieee80211_local *local = hw_to_local(hw);
1431
1432 trace_api_sched_scan_stopped(local);
1433
1434 /*
1435 * this shouldn't really happen, so for simplicity
1436 * simply ignore it, and let mac80211 reconfigure
1437 * the sched scan later on.
1438 */
1439 if (local->in_reconfig)
1440 return;
1441
1442 schedule_work(&local->sched_scan_stopped_work);
1443 }
1444 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
1445
