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) 2018-2023 Intel Corporation
13 */
14
15 #include <linux/if_arp.h>
16 #include <linux/etherdevice.h>
17 #include <linux/rtnetlink.h>
18 #include <net/sch_generic.h>
19 #include <linux/slab.h>
20 #include <linux/export.h>
21 #include <linux/random.h>
22 #include <net/mac80211.h>
23
24 #include "ieee80211_i.h"
25 #include "driver-ops.h"
26 #include "mesh.h"
27
28 #define IEEE80211_PROBE_DELAY (HZ / 33)
29 #define IEEE80211_CHANNEL_TIME (HZ / 33)
30 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
31
ieee80211_rx_bss_put(struct ieee80211_local * local,struct ieee80211_bss * bss)32 void ieee80211_rx_bss_put(struct ieee80211_local *local,
33 struct ieee80211_bss *bss)
34 {
35 if (!bss)
36 return;
37 cfg80211_put_bss(local->hw.wiphy,
38 container_of((void *)bss, struct cfg80211_bss, priv));
39 }
40
is_uapsd_supported(struct ieee802_11_elems * elems)41 static bool is_uapsd_supported(struct ieee802_11_elems *elems)
42 {
43 u8 qos_info;
44
45 if (elems->wmm_info && elems->wmm_info_len == 7
46 && elems->wmm_info[5] == 1)
47 qos_info = elems->wmm_info[6];
48 else if (elems->wmm_param && elems->wmm_param_len == 24
49 && elems->wmm_param[5] == 1)
50 qos_info = elems->wmm_param[6];
51 else
52 /* no valid wmm information or parameter element found */
53 return false;
54
55 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
56 }
57
58 struct inform_bss_update_data {
59 struct ieee80211_rx_status *rx_status;
60 bool beacon;
61 };
62
ieee80211_inform_bss(struct wiphy * wiphy,struct cfg80211_bss * cbss,const struct cfg80211_bss_ies * ies,void * data)63 void ieee80211_inform_bss(struct wiphy *wiphy,
64 struct cfg80211_bss *cbss,
65 const struct cfg80211_bss_ies *ies,
66 void *data)
67 {
68 struct ieee80211_local *local = wiphy_priv(wiphy);
69 struct inform_bss_update_data *update_data = data;
70 struct ieee80211_bss *bss = (void *)cbss->priv;
71 struct ieee80211_rx_status *rx_status;
72 struct ieee802_11_elems *elems;
73 int clen, srlen;
74
75 /* This happens while joining an IBSS */
76 if (!update_data)
77 return;
78
79 elems = ieee802_11_parse_elems(ies->data, ies->len, false, NULL);
80 if (!elems)
81 return;
82
83 rx_status = update_data->rx_status;
84
85 if (update_data->beacon)
86 bss->device_ts_beacon = rx_status->device_timestamp;
87 else
88 bss->device_ts_presp = rx_status->device_timestamp;
89
90 if (elems->parse_error) {
91 if (update_data->beacon)
92 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
93 else
94 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
95 } else {
96 if (update_data->beacon)
97 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
98 else
99 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
100 }
101
102 /* save the ERP value so that it is available at association time */
103 if (elems->erp_info && (!elems->parse_error ||
104 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
105 bss->erp_value = elems->erp_info[0];
106 bss->has_erp_value = true;
107 if (!elems->parse_error)
108 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
109 }
110
111 /* replace old supported rates if we get new values */
112 if (!elems->parse_error ||
113 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
114 srlen = 0;
115 if (elems->supp_rates) {
116 clen = IEEE80211_MAX_SUPP_RATES;
117 if (clen > elems->supp_rates_len)
118 clen = elems->supp_rates_len;
119 memcpy(bss->supp_rates, elems->supp_rates, clen);
120 srlen += clen;
121 }
122 if (elems->ext_supp_rates) {
123 clen = IEEE80211_MAX_SUPP_RATES - srlen;
124 if (clen > elems->ext_supp_rates_len)
125 clen = elems->ext_supp_rates_len;
126 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
127 clen);
128 srlen += clen;
129 }
130 if (srlen) {
131 bss->supp_rates_len = srlen;
132 if (!elems->parse_error)
133 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
134 }
135 }
136
137 if (!elems->parse_error ||
138 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
139 bss->wmm_used = elems->wmm_param || elems->wmm_info;
140 bss->uapsd_supported = is_uapsd_supported(elems);
141 if (!elems->parse_error)
142 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
143 }
144
145 if (update_data->beacon) {
146 struct ieee80211_supported_band *sband =
147 local->hw.wiphy->bands[rx_status->band];
148 if (!(rx_status->encoding == RX_ENC_HT) &&
149 !(rx_status->encoding == RX_ENC_VHT))
150 bss->beacon_rate =
151 &sband->bitrates[rx_status->rate_idx];
152 }
153
154 if (elems->vht_cap_elem)
155 bss->vht_cap_info =
156 le32_to_cpu(elems->vht_cap_elem->vht_cap_info);
157 else
158 bss->vht_cap_info = 0;
159
160 kfree(elems);
161 }
162
163 struct ieee80211_bss *
ieee80211_bss_info_update(struct ieee80211_local * local,struct ieee80211_rx_status * rx_status,struct ieee80211_mgmt * mgmt,size_t len,struct ieee80211_channel * channel)164 ieee80211_bss_info_update(struct ieee80211_local *local,
165 struct ieee80211_rx_status *rx_status,
166 struct ieee80211_mgmt *mgmt, size_t len,
167 struct ieee80211_channel *channel)
168 {
169 bool beacon = ieee80211_is_beacon(mgmt->frame_control) ||
170 ieee80211_is_s1g_beacon(mgmt->frame_control);
171 struct cfg80211_bss *cbss;
172 struct inform_bss_update_data update_data = {
173 .rx_status = rx_status,
174 .beacon = beacon,
175 };
176 struct cfg80211_inform_bss bss_meta = {
177 .boottime_ns = rx_status->boottime_ns,
178 .drv_data = (void *)&update_data,
179 };
180 bool signal_valid;
181 struct ieee80211_sub_if_data *scan_sdata;
182
183 if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
184 bss_meta.signal = 0; /* invalid signal indication */
185 else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
186 bss_meta.signal = rx_status->signal * 100;
187 else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
188 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
189
190 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
191 if (rx_status->bw == RATE_INFO_BW_5)
192 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
193 else if (rx_status->bw == RATE_INFO_BW_10)
194 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
195
196 bss_meta.chan = channel;
197
198 rcu_read_lock();
199 scan_sdata = rcu_dereference(local->scan_sdata);
200 if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
201 scan_sdata->vif.cfg.assoc &&
202 ieee80211_have_rx_timestamp(rx_status)) {
203 bss_meta.parent_tsf =
204 ieee80211_calculate_rx_timestamp(local, rx_status,
205 len + FCS_LEN, 24);
206 ether_addr_copy(bss_meta.parent_bssid,
207 scan_sdata->vif.bss_conf.bssid);
208 }
209 rcu_read_unlock();
210
211 cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
212 mgmt, len, GFP_ATOMIC);
213 if (!cbss)
214 return NULL;
215
216 /* In case the signal is invalid update the status */
217 signal_valid = channel == cbss->channel;
218 if (!signal_valid)
219 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
220
221 return (void *)cbss->priv;
222 }
223
ieee80211_scan_accept_presp(struct ieee80211_sub_if_data * sdata,u32 scan_flags,const u8 * da)224 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
225 u32 scan_flags, const u8 *da)
226 {
227 if (!sdata)
228 return false;
229 /* accept broadcast for OCE */
230 if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
231 is_broadcast_ether_addr(da))
232 return true;
233 if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
234 return true;
235 return ether_addr_equal(da, sdata->vif.addr);
236 }
237
ieee80211_scan_rx(struct ieee80211_local * local,struct sk_buff * skb)238 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
239 {
240 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
241 struct ieee80211_sub_if_data *sdata1, *sdata2;
242 struct ieee80211_mgmt *mgmt = (void *)skb->data;
243 struct ieee80211_bss *bss;
244 struct ieee80211_channel *channel;
245 size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
246 u.probe_resp.variable);
247
248 if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
249 !ieee80211_is_beacon(mgmt->frame_control) &&
250 !ieee80211_is_s1g_beacon(mgmt->frame_control))
251 return;
252
253 if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
254 if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
255 min_hdr_len = offsetof(struct ieee80211_ext,
256 u.s1g_short_beacon.variable);
257 else
258 min_hdr_len = offsetof(struct ieee80211_ext,
259 u.s1g_beacon);
260 }
261
262 if (skb->len < min_hdr_len)
263 return;
264
265 sdata1 = rcu_dereference(local->scan_sdata);
266 sdata2 = rcu_dereference(local->sched_scan_sdata);
267
268 if (likely(!sdata1 && !sdata2))
269 return;
270
271 if (test_and_clear_bit(SCAN_BEACON_WAIT, &local->scanning)) {
272 /*
273 * we were passive scanning because of radar/no-IR, but
274 * the beacon/proberesp rx gives us an opportunity to upgrade
275 * to active scan
276 */
277 set_bit(SCAN_BEACON_DONE, &local->scanning);
278 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
279 }
280
281 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
282 struct cfg80211_scan_request *scan_req;
283 struct cfg80211_sched_scan_request *sched_scan_req;
284 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
285
286 scan_req = rcu_dereference(local->scan_req);
287 sched_scan_req = rcu_dereference(local->sched_scan_req);
288
289 if (scan_req)
290 scan_req_flags = scan_req->flags;
291
292 if (sched_scan_req)
293 sched_scan_req_flags = sched_scan_req->flags;
294
295 /* ignore ProbeResp to foreign address or non-bcast (OCE)
296 * unless scanning with randomised address
297 */
298 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
299 mgmt->da) &&
300 !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
301 mgmt->da))
302 return;
303 }
304
305 channel = ieee80211_get_channel_khz(local->hw.wiphy,
306 ieee80211_rx_status_to_khz(rx_status));
307
308 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
309 return;
310
311 bss = ieee80211_bss_info_update(local, rx_status,
312 mgmt, skb->len,
313 channel);
314 if (bss)
315 ieee80211_rx_bss_put(local, bss);
316 }
317
318 static void
ieee80211_prepare_scan_chandef(struct cfg80211_chan_def * chandef,enum nl80211_bss_scan_width scan_width)319 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
320 enum nl80211_bss_scan_width scan_width)
321 {
322 memset(chandef, 0, sizeof(*chandef));
323 switch (scan_width) {
324 case NL80211_BSS_CHAN_WIDTH_5:
325 chandef->width = NL80211_CHAN_WIDTH_5;
326 break;
327 case NL80211_BSS_CHAN_WIDTH_10:
328 chandef->width = NL80211_CHAN_WIDTH_10;
329 break;
330 default:
331 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
332 break;
333 }
334 }
335
336 /* return false if no more work */
ieee80211_prep_hw_scan(struct ieee80211_sub_if_data * sdata)337 static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
338 {
339 struct ieee80211_local *local = sdata->local;
340 struct cfg80211_scan_request *req;
341 struct cfg80211_chan_def chandef;
342 u8 bands_used = 0;
343 int i, ielen, n_chans;
344 u32 flags = 0;
345
346 req = rcu_dereference_protected(local->scan_req,
347 lockdep_is_held(&local->mtx));
348
349 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
350 return false;
351
352 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
353 for (i = 0; i < req->n_channels; i++) {
354 local->hw_scan_req->req.channels[i] = req->channels[i];
355 bands_used |= BIT(req->channels[i]->band);
356 }
357
358 n_chans = req->n_channels;
359 } else {
360 do {
361 if (local->hw_scan_band == NUM_NL80211_BANDS)
362 return false;
363
364 n_chans = 0;
365
366 for (i = 0; i < req->n_channels; i++) {
367 if (req->channels[i]->band !=
368 local->hw_scan_band)
369 continue;
370 local->hw_scan_req->req.channels[n_chans] =
371 req->channels[i];
372 n_chans++;
373 bands_used |= BIT(req->channels[i]->band);
374 }
375
376 local->hw_scan_band++;
377 } while (!n_chans);
378 }
379
380 local->hw_scan_req->req.n_channels = n_chans;
381 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
382
383 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
384 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
385
386 ielen = ieee80211_build_preq_ies(sdata,
387 (u8 *)local->hw_scan_req->req.ie,
388 local->hw_scan_ies_bufsize,
389 &local->hw_scan_req->ies,
390 req->ie, req->ie_len,
391 bands_used, req->rates, &chandef,
392 flags);
393 local->hw_scan_req->req.ie_len = ielen;
394 local->hw_scan_req->req.no_cck = req->no_cck;
395 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
396 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
397 req->mac_addr_mask);
398 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
399
400 return true;
401 }
402
__ieee80211_scan_completed(struct ieee80211_hw * hw,bool aborted)403 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
404 {
405 struct ieee80211_local *local = hw_to_local(hw);
406 bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
407 bool was_scanning = local->scanning;
408 struct cfg80211_scan_request *scan_req;
409 struct ieee80211_sub_if_data *scan_sdata;
410 struct ieee80211_sub_if_data *sdata;
411
412 lockdep_assert_held(&local->mtx);
413
414 /*
415 * It's ok to abort a not-yet-running scan (that
416 * we have one at all will be verified by checking
417 * local->scan_req next), but not to complete it
418 * successfully.
419 */
420 if (WARN_ON(!local->scanning && !aborted))
421 aborted = true;
422
423 if (WARN_ON(!local->scan_req))
424 return;
425
426 scan_sdata = rcu_dereference_protected(local->scan_sdata,
427 lockdep_is_held(&local->mtx));
428
429 if (hw_scan && !aborted &&
430 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
431 ieee80211_prep_hw_scan(scan_sdata)) {
432 int rc;
433
434 rc = drv_hw_scan(local,
435 rcu_dereference_protected(local->scan_sdata,
436 lockdep_is_held(&local->mtx)),
437 local->hw_scan_req);
438
439 if (rc == 0)
440 return;
441
442 /* HW scan failed and is going to be reported as aborted,
443 * so clear old scan info.
444 */
445 memset(&local->scan_info, 0, sizeof(local->scan_info));
446 aborted = true;
447 }
448
449 kfree(local->hw_scan_req);
450 local->hw_scan_req = NULL;
451
452 scan_req = rcu_dereference_protected(local->scan_req,
453 lockdep_is_held(&local->mtx));
454
455 RCU_INIT_POINTER(local->scan_req, NULL);
456 RCU_INIT_POINTER(local->scan_sdata, NULL);
457
458 local->scanning = 0;
459 local->scan_chandef.chan = NULL;
460
461 synchronize_rcu();
462
463 if (scan_req != local->int_scan_req) {
464 local->scan_info.aborted = aborted;
465 cfg80211_scan_done(scan_req, &local->scan_info);
466 }
467
468 /* Set power back to normal operating levels. */
469 ieee80211_hw_config(local, 0);
470
471 if (!hw_scan && was_scanning) {
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 wiphy_work_queue(sdata->local->hw.wiphy, &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_u16();
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 if (req->n_ssids)
791 set_bit(SCAN_BEACON_WAIT, &local->scanning);
792 } else {
793 ieee80211_scan_state_send_probe(local, &next_delay);
794 next_delay = IEEE80211_CHANNEL_TIME;
795 }
796
797 /* Now, just wait a bit and we are all done! */
798 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
799 next_delay);
800 return 0;
801 } else {
802 /* Do normal software scan */
803 __set_bit(SCAN_SW_SCANNING, &local->scanning);
804 }
805
806 ieee80211_recalc_idle(local);
807
808 if (hw_scan) {
809 WARN_ON(!ieee80211_prep_hw_scan(sdata));
810 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
811 } else {
812 rc = ieee80211_start_sw_scan(local, sdata);
813 }
814
815 if (rc) {
816 kfree(local->hw_scan_req);
817 local->hw_scan_req = NULL;
818 local->scanning = 0;
819
820 ieee80211_recalc_idle(local);
821
822 local->scan_req = NULL;
823 RCU_INIT_POINTER(local->scan_sdata, NULL);
824 }
825
826 if (hw_scan && rc == 1) {
827 /*
828 * we can't fall back to software for P2P-GO
829 * as it must update NoA etc.
830 */
831 if (ieee80211_vif_type_p2p(&sdata->vif) ==
832 NL80211_IFTYPE_P2P_GO)
833 return -EOPNOTSUPP;
834 hw_scan = false;
835 goto again;
836 }
837
838 return rc;
839 }
840
841 static unsigned long
ieee80211_scan_get_channel_time(struct ieee80211_channel * chan)842 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
843 {
844 /*
845 * TODO: channel switching also consumes quite some time,
846 * add that delay as well to get a better estimation
847 */
848 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
849 return IEEE80211_PASSIVE_CHANNEL_TIME;
850 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
851 }
852
ieee80211_scan_state_decision(struct ieee80211_local * local,unsigned long * next_delay)853 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
854 unsigned long *next_delay)
855 {
856 bool associated = false;
857 bool tx_empty = true;
858 bool bad_latency;
859 struct ieee80211_sub_if_data *sdata;
860 struct ieee80211_channel *next_chan;
861 enum mac80211_scan_state next_scan_state;
862 struct cfg80211_scan_request *scan_req;
863
864 /*
865 * check if at least one STA interface is associated,
866 * check if at least one STA interface has pending tx frames
867 * and grab the lowest used beacon interval
868 */
869 mutex_lock(&local->iflist_mtx);
870 list_for_each_entry(sdata, &local->interfaces, list) {
871 if (!ieee80211_sdata_running(sdata))
872 continue;
873
874 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
875 if (sdata->u.mgd.associated) {
876 associated = true;
877
878 if (!qdisc_all_tx_empty(sdata->dev)) {
879 tx_empty = false;
880 break;
881 }
882 }
883 }
884 }
885 mutex_unlock(&local->iflist_mtx);
886
887 scan_req = rcu_dereference_protected(local->scan_req,
888 lockdep_is_held(&local->mtx));
889
890 next_chan = scan_req->channels[local->scan_channel_idx];
891
892 /*
893 * we're currently scanning a different channel, let's
894 * see if we can scan another channel without interfering
895 * with the current traffic situation.
896 *
897 * Keep good latency, do not stay off-channel more than 125 ms.
898 */
899
900 bad_latency = time_after(jiffies +
901 ieee80211_scan_get_channel_time(next_chan),
902 local->leave_oper_channel_time + HZ / 8);
903
904 if (associated && !tx_empty) {
905 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
906 next_scan_state = SCAN_ABORT;
907 else
908 next_scan_state = SCAN_SUSPEND;
909 } else if (associated && bad_latency) {
910 next_scan_state = SCAN_SUSPEND;
911 } else {
912 next_scan_state = SCAN_SET_CHANNEL;
913 }
914
915 local->next_scan_state = next_scan_state;
916
917 *next_delay = 0;
918 }
919
ieee80211_scan_state_set_channel(struct ieee80211_local * local,unsigned long * next_delay)920 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
921 unsigned long *next_delay)
922 {
923 int skip;
924 struct ieee80211_channel *chan;
925 enum nl80211_bss_scan_width oper_scan_width;
926 struct cfg80211_scan_request *scan_req;
927
928 scan_req = rcu_dereference_protected(local->scan_req,
929 lockdep_is_held(&local->mtx));
930
931 skip = 0;
932 chan = scan_req->channels[local->scan_channel_idx];
933
934 local->scan_chandef.chan = chan;
935 local->scan_chandef.center_freq1 = chan->center_freq;
936 local->scan_chandef.freq1_offset = chan->freq_offset;
937 local->scan_chandef.center_freq2 = 0;
938
939 /* For scanning on the S1G band, ignore scan_width (which is constant
940 * across all channels) for now since channel width is specific to each
941 * channel. Detect the required channel width here and likely revisit
942 * later. Maybe scan_width could be used to build the channel scan list?
943 */
944 if (chan->band == NL80211_BAND_S1GHZ) {
945 local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
946 goto set_channel;
947 }
948
949 switch (scan_req->scan_width) {
950 case NL80211_BSS_CHAN_WIDTH_5:
951 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
952 break;
953 case NL80211_BSS_CHAN_WIDTH_10:
954 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
955 break;
956 default:
957 case NL80211_BSS_CHAN_WIDTH_20:
958 /* If scanning on oper channel, use whatever channel-type
959 * is currently in use.
960 */
961 oper_scan_width = cfg80211_chandef_to_scan_width(
962 &local->_oper_chandef);
963 if (chan == local->_oper_chandef.chan &&
964 oper_scan_width == scan_req->scan_width)
965 local->scan_chandef = local->_oper_chandef;
966 else
967 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
968 break;
969 case NL80211_BSS_CHAN_WIDTH_1:
970 case NL80211_BSS_CHAN_WIDTH_2:
971 /* shouldn't get here, S1G handled above */
972 WARN_ON(1);
973 break;
974 }
975
976 set_channel:
977 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
978 skip = 1;
979
980 /* advance state machine to next channel/band */
981 local->scan_channel_idx++;
982
983 if (skip) {
984 /* if we skip this channel return to the decision state */
985 local->next_scan_state = SCAN_DECISION;
986 return;
987 }
988
989 /*
990 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
991 * (which unfortunately doesn't say _why_ step a) is done,
992 * but it waits for the probe delay or until a frame is
993 * received - and the received frame would update the NAV).
994 * For now, we do not support waiting until a frame is
995 * received.
996 *
997 * In any case, it is not necessary for a passive scan.
998 */
999 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
1000 !scan_req->n_ssids) {
1001 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
1002 local->next_scan_state = SCAN_DECISION;
1003 if (scan_req->n_ssids)
1004 set_bit(SCAN_BEACON_WAIT, &local->scanning);
1005 return;
1006 }
1007
1008 /* active scan, send probes */
1009 *next_delay = IEEE80211_PROBE_DELAY;
1010 local->next_scan_state = SCAN_SEND_PROBE;
1011 }
1012
ieee80211_scan_state_suspend(struct ieee80211_local * local,unsigned long * next_delay)1013 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1014 unsigned long *next_delay)
1015 {
1016 /* switch back to the operating channel */
1017 local->scan_chandef.chan = NULL;
1018 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
1019
1020 /* disable PS */
1021 ieee80211_offchannel_return(local);
1022
1023 *next_delay = HZ / 5;
1024 /* afterwards, resume scan & go to next channel */
1025 local->next_scan_state = SCAN_RESUME;
1026 }
1027
ieee80211_scan_state_resume(struct ieee80211_local * local,unsigned long * next_delay)1028 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1029 unsigned long *next_delay)
1030 {
1031 ieee80211_offchannel_stop_vifs(local);
1032
1033 if (local->ops->flush) {
1034 ieee80211_flush_queues(local, NULL, false);
1035 *next_delay = 0;
1036 } else
1037 *next_delay = HZ / 10;
1038
1039 /* remember when we left the operating channel */
1040 local->leave_oper_channel_time = jiffies;
1041
1042 /* advance to the next channel to be scanned */
1043 local->next_scan_state = SCAN_SET_CHANNEL;
1044 }
1045
ieee80211_scan_work(struct work_struct * work)1046 void ieee80211_scan_work(struct work_struct *work)
1047 {
1048 struct ieee80211_local *local =
1049 container_of(work, struct ieee80211_local, scan_work.work);
1050 struct ieee80211_sub_if_data *sdata;
1051 struct cfg80211_scan_request *scan_req;
1052 unsigned long next_delay = 0;
1053 bool aborted;
1054
1055 mutex_lock(&local->mtx);
1056
1057 if (!ieee80211_can_run_worker(local)) {
1058 aborted = true;
1059 goto out_complete;
1060 }
1061
1062 sdata = rcu_dereference_protected(local->scan_sdata,
1063 lockdep_is_held(&local->mtx));
1064 scan_req = rcu_dereference_protected(local->scan_req,
1065 lockdep_is_held(&local->mtx));
1066
1067 /* When scanning on-channel, the first-callback means completed. */
1068 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1069 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1070 goto out_complete;
1071 }
1072
1073 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1074 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1075 goto out_complete;
1076 }
1077
1078 if (!sdata || !scan_req)
1079 goto out;
1080
1081 if (!local->scanning) {
1082 int rc;
1083
1084 RCU_INIT_POINTER(local->scan_req, NULL);
1085 RCU_INIT_POINTER(local->scan_sdata, NULL);
1086
1087 rc = __ieee80211_start_scan(sdata, scan_req);
1088 if (rc) {
1089 /* need to complete scan in cfg80211 */
1090 rcu_assign_pointer(local->scan_req, scan_req);
1091 aborted = true;
1092 goto out_complete;
1093 } else
1094 goto out;
1095 }
1096
1097 clear_bit(SCAN_BEACON_WAIT, &local->scanning);
1098
1099 /*
1100 * as long as no delay is required advance immediately
1101 * without scheduling a new work
1102 */
1103 do {
1104 if (!ieee80211_sdata_running(sdata)) {
1105 aborted = true;
1106 goto out_complete;
1107 }
1108
1109 if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) &&
1110 local->next_scan_state == SCAN_DECISION)
1111 local->next_scan_state = SCAN_SEND_PROBE;
1112
1113 switch (local->next_scan_state) {
1114 case SCAN_DECISION:
1115 /* if no more bands/channels left, complete scan */
1116 if (local->scan_channel_idx >= scan_req->n_channels) {
1117 aborted = false;
1118 goto out_complete;
1119 }
1120 ieee80211_scan_state_decision(local, &next_delay);
1121 break;
1122 case SCAN_SET_CHANNEL:
1123 ieee80211_scan_state_set_channel(local, &next_delay);
1124 break;
1125 case SCAN_SEND_PROBE:
1126 ieee80211_scan_state_send_probe(local, &next_delay);
1127 break;
1128 case SCAN_SUSPEND:
1129 ieee80211_scan_state_suspend(local, &next_delay);
1130 break;
1131 case SCAN_RESUME:
1132 ieee80211_scan_state_resume(local, &next_delay);
1133 break;
1134 case SCAN_ABORT:
1135 aborted = true;
1136 goto out_complete;
1137 }
1138 } while (next_delay == 0);
1139
1140 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
1141 goto out;
1142
1143 out_complete:
1144 __ieee80211_scan_completed(&local->hw, aborted);
1145 out:
1146 mutex_unlock(&local->mtx);
1147 }
1148
ieee80211_request_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)1149 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1150 struct cfg80211_scan_request *req)
1151 {
1152 int res;
1153
1154 mutex_lock(&sdata->local->mtx);
1155 res = __ieee80211_start_scan(sdata, req);
1156 mutex_unlock(&sdata->local->mtx);
1157
1158 return res;
1159 }
1160
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)1161 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1162 const u8 *ssid, u8 ssid_len,
1163 struct ieee80211_channel **channels,
1164 unsigned int n_channels,
1165 enum nl80211_bss_scan_width scan_width)
1166 {
1167 struct ieee80211_local *local = sdata->local;
1168 int ret = -EBUSY, i, n_ch = 0;
1169 enum nl80211_band band;
1170
1171 mutex_lock(&local->mtx);
1172
1173 /* busy scanning */
1174 if (local->scan_req)
1175 goto unlock;
1176
1177 /* fill internal scan request */
1178 if (!channels) {
1179 int max_n;
1180
1181 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1182 if (!local->hw.wiphy->bands[band] ||
1183 band == NL80211_BAND_6GHZ)
1184 continue;
1185
1186 max_n = local->hw.wiphy->bands[band]->n_channels;
1187 for (i = 0; i < max_n; i++) {
1188 struct ieee80211_channel *tmp_ch =
1189 &local->hw.wiphy->bands[band]->channels[i];
1190
1191 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1192 IEEE80211_CHAN_DISABLED))
1193 continue;
1194
1195 local->int_scan_req->channels[n_ch] = tmp_ch;
1196 n_ch++;
1197 }
1198 }
1199
1200 if (WARN_ON_ONCE(n_ch == 0))
1201 goto unlock;
1202
1203 local->int_scan_req->n_channels = n_ch;
1204 } else {
1205 for (i = 0; i < n_channels; i++) {
1206 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1207 IEEE80211_CHAN_DISABLED))
1208 continue;
1209
1210 local->int_scan_req->channels[n_ch] = channels[i];
1211 n_ch++;
1212 }
1213
1214 if (WARN_ON_ONCE(n_ch == 0))
1215 goto unlock;
1216
1217 local->int_scan_req->n_channels = n_ch;
1218 }
1219
1220 local->int_scan_req->ssids = &local->scan_ssid;
1221 local->int_scan_req->n_ssids = 1;
1222 local->int_scan_req->scan_width = scan_width;
1223 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1224 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1225
1226 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1227 unlock:
1228 mutex_unlock(&local->mtx);
1229 return ret;
1230 }
1231
ieee80211_scan_cancel(struct ieee80211_local * local)1232 void ieee80211_scan_cancel(struct ieee80211_local *local)
1233 {
1234 /* ensure a new scan cannot be queued */
1235 lockdep_assert_wiphy(local->hw.wiphy);
1236
1237 /*
1238 * We are canceling software scan, or deferred scan that was not
1239 * yet really started (see __ieee80211_start_scan ).
1240 *
1241 * Regarding hardware scan:
1242 * - we can not call __ieee80211_scan_completed() as when
1243 * SCAN_HW_SCANNING bit is set this function change
1244 * local->hw_scan_req to operate on 5G band, what race with
1245 * driver which can use local->hw_scan_req
1246 *
1247 * - we can not cancel scan_work since driver can schedule it
1248 * by ieee80211_scan_completed(..., true) to finish scan
1249 *
1250 * Hence we only call the cancel_hw_scan() callback, but the low-level
1251 * driver is still responsible for calling ieee80211_scan_completed()
1252 * after the scan was completed/aborted.
1253 */
1254
1255 mutex_lock(&local->mtx);
1256 if (!local->scan_req)
1257 goto out;
1258
1259 /*
1260 * We have a scan running and the driver already reported completion,
1261 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1262 * cancelled.
1263 */
1264 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1265 test_bit(SCAN_COMPLETED, &local->scanning)) {
1266 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1267 goto out;
1268 }
1269
1270 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1271 /*
1272 * Make sure that __ieee80211_scan_completed doesn't trigger a
1273 * scan on another band.
1274 */
1275 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1276 if (local->ops->cancel_hw_scan)
1277 drv_cancel_hw_scan(local,
1278 rcu_dereference_protected(local->scan_sdata,
1279 lockdep_is_held(&local->mtx)));
1280 goto out;
1281 }
1282
1283 /*
1284 * If the work is currently running, it must be blocked on
1285 * the mutex, but we'll set scan_sdata = NULL and it'll
1286 * simply exit once it acquires the mutex.
1287 */
1288 cancel_delayed_work(&local->scan_work);
1289 /* and clean up */
1290 memset(&local->scan_info, 0, sizeof(local->scan_info));
1291 __ieee80211_scan_completed(&local->hw, true);
1292 out:
1293 mutex_unlock(&local->mtx);
1294 }
1295
__ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1296 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1297 struct cfg80211_sched_scan_request *req)
1298 {
1299 struct ieee80211_local *local = sdata->local;
1300 struct ieee80211_scan_ies sched_scan_ies = {};
1301 struct cfg80211_chan_def chandef;
1302 int ret, i, iebufsz, num_bands = 0;
1303 u32 rate_masks[NUM_NL80211_BANDS] = {};
1304 u8 bands_used = 0;
1305 u8 *ie;
1306 u32 flags = 0;
1307
1308 iebufsz = local->scan_ies_len + req->ie_len;
1309
1310 lockdep_assert_held(&local->mtx);
1311
1312 if (!local->ops->sched_scan_start)
1313 return -ENOTSUPP;
1314
1315 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1316 if (local->hw.wiphy->bands[i]) {
1317 bands_used |= BIT(i);
1318 rate_masks[i] = (u32) -1;
1319 num_bands++;
1320 }
1321 }
1322
1323 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1324 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1325
1326 ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1327 if (!ie) {
1328 ret = -ENOMEM;
1329 goto out;
1330 }
1331
1332 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1333
1334 ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1335 &sched_scan_ies, req->ie,
1336 req->ie_len, bands_used, rate_masks, &chandef,
1337 flags);
1338
1339 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1340 if (ret == 0) {
1341 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1342 rcu_assign_pointer(local->sched_scan_req, req);
1343 }
1344
1345 kfree(ie);
1346
1347 out:
1348 if (ret) {
1349 /* Clean in case of failure after HW restart or upon resume. */
1350 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1351 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1352 }
1353
1354 return ret;
1355 }
1356
ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1357 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1358 struct cfg80211_sched_scan_request *req)
1359 {
1360 struct ieee80211_local *local = sdata->local;
1361 int ret;
1362
1363 mutex_lock(&local->mtx);
1364
1365 if (rcu_access_pointer(local->sched_scan_sdata)) {
1366 mutex_unlock(&local->mtx);
1367 return -EBUSY;
1368 }
1369
1370 ret = __ieee80211_request_sched_scan_start(sdata, req);
1371
1372 mutex_unlock(&local->mtx);
1373 return ret;
1374 }
1375
ieee80211_request_sched_scan_stop(struct ieee80211_local * local)1376 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1377 {
1378 struct ieee80211_sub_if_data *sched_scan_sdata;
1379 int ret = -ENOENT;
1380
1381 mutex_lock(&local->mtx);
1382
1383 if (!local->ops->sched_scan_stop) {
1384 ret = -ENOTSUPP;
1385 goto out;
1386 }
1387
1388 /* We don't want to restart sched scan anymore. */
1389 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1390
1391 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1392 lockdep_is_held(&local->mtx));
1393 if (sched_scan_sdata) {
1394 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1395 if (!ret)
1396 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1397 }
1398 out:
1399 mutex_unlock(&local->mtx);
1400
1401 return ret;
1402 }
1403
ieee80211_sched_scan_results(struct ieee80211_hw * hw)1404 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1405 {
1406 struct ieee80211_local *local = hw_to_local(hw);
1407
1408 trace_api_sched_scan_results(local);
1409
1410 cfg80211_sched_scan_results(hw->wiphy, 0);
1411 }
1412 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1413
ieee80211_sched_scan_end(struct ieee80211_local * local)1414 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1415 {
1416 mutex_lock(&local->mtx);
1417
1418 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1419 mutex_unlock(&local->mtx);
1420 return;
1421 }
1422
1423 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1424
1425 /* If sched scan was aborted by the driver. */
1426 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1427
1428 mutex_unlock(&local->mtx);
1429
1430 cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1431 }
1432
ieee80211_sched_scan_stopped_work(struct work_struct * work)1433 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1434 {
1435 struct ieee80211_local *local =
1436 container_of(work, struct ieee80211_local,
1437 sched_scan_stopped_work);
1438
1439 ieee80211_sched_scan_end(local);
1440 }
1441
ieee80211_sched_scan_stopped(struct ieee80211_hw * hw)1442 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1443 {
1444 struct ieee80211_local *local = hw_to_local(hw);
1445
1446 trace_api_sched_scan_stopped(local);
1447
1448 /*
1449 * this shouldn't really happen, so for simplicity
1450 * simply ignore it, and let mac80211 reconfigure
1451 * the sched scan later on.
1452 */
1453 if (local->in_reconfig)
1454 return;
1455
1456 schedule_work(&local->sched_scan_stopped_work);
1457 }
1458 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
1459
