1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Scanning implementation
4 *
5 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
6 * Copyright 2004, Instant802 Networks, Inc.
7 * Copyright 2005, Devicescape Software, Inc.
8 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
9 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
10 * Copyright 2013-2015 Intel Mobile Communications GmbH
11 * Copyright 2016-2017 Intel Deutschland GmbH
12 * Copyright (C) 2018-2021 Intel Corporation
13 */
14
15 #include <linux/if_arp.h>
16 #include <linux/etherdevice.h>
17 #include <linux/rtnetlink.h>
18 #include <net/sch_generic.h>
19 #include <linux/slab.h>
20 #include <linux/export.h>
21 #include <linux/random.h>
22 #include <net/mac80211.h>
23
24 #include "ieee80211_i.h"
25 #include "driver-ops.h"
26 #include "mesh.h"
27
28 #define IEEE80211_PROBE_DELAY (HZ / 33)
29 #define IEEE80211_CHANNEL_TIME (HZ / 33)
30 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
31
ieee80211_rx_bss_put(struct ieee80211_local * local,struct ieee80211_bss * bss)32 void ieee80211_rx_bss_put(struct ieee80211_local *local,
33 struct ieee80211_bss *bss)
34 {
35 if (!bss)
36 return;
37 cfg80211_put_bss(local->hw.wiphy,
38 container_of((void *)bss, struct cfg80211_bss, priv));
39 }
40
is_uapsd_supported(struct ieee802_11_elems * elems)41 static bool is_uapsd_supported(struct ieee802_11_elems *elems)
42 {
43 u8 qos_info;
44
45 if (elems->wmm_info && elems->wmm_info_len == 7
46 && elems->wmm_info[5] == 1)
47 qos_info = elems->wmm_info[6];
48 else if (elems->wmm_param && elems->wmm_param_len == 24
49 && elems->wmm_param[5] == 1)
50 qos_info = elems->wmm_param[6];
51 else
52 /* no valid wmm information or parameter element found */
53 return false;
54
55 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
56 }
57
58 static void
ieee80211_update_bss_from_elems(struct ieee80211_local * local,struct ieee80211_bss * bss,struct ieee802_11_elems * elems,struct ieee80211_rx_status * rx_status,bool beacon)59 ieee80211_update_bss_from_elems(struct ieee80211_local *local,
60 struct ieee80211_bss *bss,
61 struct ieee802_11_elems *elems,
62 struct ieee80211_rx_status *rx_status,
63 bool beacon)
64 {
65 int clen, srlen;
66
67 if (beacon)
68 bss->device_ts_beacon = rx_status->device_timestamp;
69 else
70 bss->device_ts_presp = rx_status->device_timestamp;
71
72 if (elems->parse_error) {
73 if (beacon)
74 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
75 else
76 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
77 } else {
78 if (beacon)
79 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
80 else
81 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
82 }
83
84 /* save the ERP value so that it is available at association time */
85 if (elems->erp_info && (!elems->parse_error ||
86 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
87 bss->erp_value = elems->erp_info[0];
88 bss->has_erp_value = true;
89 if (!elems->parse_error)
90 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
91 }
92
93 /* replace old supported rates if we get new values */
94 if (!elems->parse_error ||
95 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
96 srlen = 0;
97 if (elems->supp_rates) {
98 clen = IEEE80211_MAX_SUPP_RATES;
99 if (clen > elems->supp_rates_len)
100 clen = elems->supp_rates_len;
101 memcpy(bss->supp_rates, elems->supp_rates, clen);
102 srlen += clen;
103 }
104 if (elems->ext_supp_rates) {
105 clen = IEEE80211_MAX_SUPP_RATES - srlen;
106 if (clen > elems->ext_supp_rates_len)
107 clen = elems->ext_supp_rates_len;
108 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
109 clen);
110 srlen += clen;
111 }
112 if (srlen) {
113 bss->supp_rates_len = srlen;
114 if (!elems->parse_error)
115 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
116 }
117 }
118
119 if (!elems->parse_error ||
120 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
121 bss->wmm_used = elems->wmm_param || elems->wmm_info;
122 bss->uapsd_supported = is_uapsd_supported(elems);
123 if (!elems->parse_error)
124 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
125 }
126
127 if (beacon) {
128 struct ieee80211_supported_band *sband =
129 local->hw.wiphy->bands[rx_status->band];
130 if (!(rx_status->encoding == RX_ENC_HT) &&
131 !(rx_status->encoding == RX_ENC_VHT))
132 bss->beacon_rate =
133 &sband->bitrates[rx_status->rate_idx];
134 }
135
136 if (elems->vht_cap_elem)
137 bss->vht_cap_info =
138 le32_to_cpu(elems->vht_cap_elem->vht_cap_info);
139 else
140 bss->vht_cap_info = 0;
141 }
142
143 struct ieee80211_bss *
ieee80211_bss_info_update(struct ieee80211_local * local,struct ieee80211_rx_status * rx_status,struct ieee80211_mgmt * mgmt,size_t len,struct ieee80211_channel * channel)144 ieee80211_bss_info_update(struct ieee80211_local *local,
145 struct ieee80211_rx_status *rx_status,
146 struct ieee80211_mgmt *mgmt, size_t len,
147 struct ieee80211_channel *channel)
148 {
149 bool beacon = ieee80211_is_beacon(mgmt->frame_control) ||
150 ieee80211_is_s1g_beacon(mgmt->frame_control);
151 struct cfg80211_bss *cbss, *non_tx_cbss;
152 struct ieee80211_bss *bss, *non_tx_bss;
153 struct cfg80211_inform_bss bss_meta = {
154 .boottime_ns = rx_status->boottime_ns,
155 };
156 bool signal_valid;
157 struct ieee80211_sub_if_data *scan_sdata;
158 struct ieee802_11_elems *elems;
159 size_t baselen;
160 u8 *elements;
161
162 if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
163 bss_meta.signal = 0; /* invalid signal indication */
164 else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
165 bss_meta.signal = rx_status->signal * 100;
166 else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
167 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
168
169 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
170 if (rx_status->bw == RATE_INFO_BW_5)
171 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
172 else if (rx_status->bw == RATE_INFO_BW_10)
173 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
174
175 bss_meta.chan = channel;
176
177 rcu_read_lock();
178 scan_sdata = rcu_dereference(local->scan_sdata);
179 if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
180 scan_sdata->vif.bss_conf.assoc &&
181 ieee80211_have_rx_timestamp(rx_status)) {
182 bss_meta.parent_tsf =
183 ieee80211_calculate_rx_timestamp(local, rx_status,
184 len + FCS_LEN, 24);
185 ether_addr_copy(bss_meta.parent_bssid,
186 scan_sdata->vif.bss_conf.bssid);
187 }
188 rcu_read_unlock();
189
190 cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
191 mgmt, len, GFP_ATOMIC);
192 if (!cbss)
193 return NULL;
194
195 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
196 elements = mgmt->u.probe_resp.variable;
197 baselen = offsetof(struct ieee80211_mgmt,
198 u.probe_resp.variable);
199 } else if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
200 struct ieee80211_ext *ext = (void *) mgmt;
201
202 baselen = offsetof(struct ieee80211_ext, u.s1g_beacon.variable);
203 elements = ext->u.s1g_beacon.variable;
204 } else {
205 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
206 elements = mgmt->u.beacon.variable;
207 }
208
209 if (baselen > len)
210 return NULL;
211
212 elems = ieee802_11_parse_elems(elements, len - baselen, false,
213 mgmt->bssid, cbss->bssid);
214 if (!elems)
215 return NULL;
216
217 /* In case the signal is invalid update the status */
218 signal_valid = channel == cbss->channel;
219 if (!signal_valid)
220 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
221
222 bss = (void *)cbss->priv;
223 ieee80211_update_bss_from_elems(local, bss, elems, rx_status, beacon);
224
225 list_for_each_entry(non_tx_cbss, &cbss->nontrans_list, nontrans_list) {
226 non_tx_bss = (void *)non_tx_cbss->priv;
227
228 ieee80211_update_bss_from_elems(local, non_tx_bss, elems,
229 rx_status, beacon);
230 }
231
232 kfree(elems);
233
234 return bss;
235 }
236
ieee80211_scan_accept_presp(struct ieee80211_sub_if_data * sdata,u32 scan_flags,const u8 * da)237 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
238 u32 scan_flags, const u8 *da)
239 {
240 if (!sdata)
241 return false;
242 /* accept broadcast for OCE */
243 if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
244 is_broadcast_ether_addr(da))
245 return true;
246 if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
247 return true;
248 return ether_addr_equal(da, sdata->vif.addr);
249 }
250
ieee80211_scan_rx(struct ieee80211_local * local,struct sk_buff * skb)251 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
252 {
253 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
254 struct ieee80211_sub_if_data *sdata1, *sdata2;
255 struct ieee80211_mgmt *mgmt = (void *)skb->data;
256 struct ieee80211_bss *bss;
257 struct ieee80211_channel *channel;
258 size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
259 u.probe_resp.variable);
260
261 if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
262 !ieee80211_is_beacon(mgmt->frame_control) &&
263 !ieee80211_is_s1g_beacon(mgmt->frame_control))
264 return;
265
266 if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
267 if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
268 min_hdr_len = offsetof(struct ieee80211_ext,
269 u.s1g_short_beacon.variable);
270 else
271 min_hdr_len = offsetof(struct ieee80211_ext,
272 u.s1g_beacon);
273 }
274
275 if (skb->len < min_hdr_len)
276 return;
277
278 sdata1 = rcu_dereference(local->scan_sdata);
279 sdata2 = rcu_dereference(local->sched_scan_sdata);
280
281 if (likely(!sdata1 && !sdata2))
282 return;
283
284 if (test_and_clear_bit(SCAN_BEACON_WAIT, &local->scanning)) {
285 /*
286 * we were passive scanning because of radar/no-IR, but
287 * the beacon/proberesp rx gives us an opportunity to upgrade
288 * to active scan
289 */
290 set_bit(SCAN_BEACON_DONE, &local->scanning);
291 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
292 }
293
294 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
295 struct cfg80211_scan_request *scan_req;
296 struct cfg80211_sched_scan_request *sched_scan_req;
297 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
298
299 scan_req = rcu_dereference(local->scan_req);
300 sched_scan_req = rcu_dereference(local->sched_scan_req);
301
302 if (scan_req)
303 scan_req_flags = scan_req->flags;
304
305 if (sched_scan_req)
306 sched_scan_req_flags = sched_scan_req->flags;
307
308 /* ignore ProbeResp to foreign address or non-bcast (OCE)
309 * unless scanning with randomised address
310 */
311 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
312 mgmt->da) &&
313 !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
314 mgmt->da))
315 return;
316 }
317
318 channel = ieee80211_get_channel_khz(local->hw.wiphy,
319 ieee80211_rx_status_to_khz(rx_status));
320
321 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
322 return;
323
324 bss = ieee80211_bss_info_update(local, rx_status,
325 mgmt, skb->len,
326 channel);
327 if (bss)
328 ieee80211_rx_bss_put(local, bss);
329 }
330
331 static void
ieee80211_prepare_scan_chandef(struct cfg80211_chan_def * chandef,enum nl80211_bss_scan_width scan_width)332 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
333 enum nl80211_bss_scan_width scan_width)
334 {
335 memset(chandef, 0, sizeof(*chandef));
336 switch (scan_width) {
337 case NL80211_BSS_CHAN_WIDTH_5:
338 chandef->width = NL80211_CHAN_WIDTH_5;
339 break;
340 case NL80211_BSS_CHAN_WIDTH_10:
341 chandef->width = NL80211_CHAN_WIDTH_10;
342 break;
343 default:
344 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
345 break;
346 }
347 }
348
349 /* return false if no more work */
ieee80211_prep_hw_scan(struct ieee80211_sub_if_data * sdata)350 static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
351 {
352 struct ieee80211_local *local = sdata->local;
353 struct cfg80211_scan_request *req;
354 struct cfg80211_chan_def chandef;
355 u8 bands_used = 0;
356 int i, ielen, n_chans;
357 u32 flags = 0;
358
359 req = rcu_dereference_protected(local->scan_req,
360 lockdep_is_held(&local->mtx));
361
362 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
363 return false;
364
365 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
366 for (i = 0; i < req->n_channels; i++) {
367 local->hw_scan_req->req.channels[i] = req->channels[i];
368 bands_used |= BIT(req->channels[i]->band);
369 }
370
371 n_chans = req->n_channels;
372 } else {
373 do {
374 if (local->hw_scan_band == NUM_NL80211_BANDS)
375 return false;
376
377 n_chans = 0;
378
379 for (i = 0; i < req->n_channels; i++) {
380 if (req->channels[i]->band !=
381 local->hw_scan_band)
382 continue;
383 local->hw_scan_req->req.channels[n_chans] =
384 req->channels[i];
385 n_chans++;
386 bands_used |= BIT(req->channels[i]->band);
387 }
388
389 local->hw_scan_band++;
390 } while (!n_chans);
391 }
392
393 local->hw_scan_req->req.n_channels = n_chans;
394 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
395
396 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
397 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
398
399 ielen = ieee80211_build_preq_ies(sdata,
400 (u8 *)local->hw_scan_req->req.ie,
401 local->hw_scan_ies_bufsize,
402 &local->hw_scan_req->ies,
403 req->ie, req->ie_len,
404 bands_used, req->rates, &chandef,
405 flags);
406 local->hw_scan_req->req.ie_len = ielen;
407 local->hw_scan_req->req.no_cck = req->no_cck;
408 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
409 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
410 req->mac_addr_mask);
411 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
412
413 return true;
414 }
415
__ieee80211_scan_completed(struct ieee80211_hw * hw,bool aborted)416 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
417 {
418 struct ieee80211_local *local = hw_to_local(hw);
419 bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
420 bool was_scanning = local->scanning;
421 struct cfg80211_scan_request *scan_req;
422 struct ieee80211_sub_if_data *scan_sdata;
423 struct ieee80211_sub_if_data *sdata;
424
425 lockdep_assert_held(&local->mtx);
426
427 /*
428 * It's ok to abort a not-yet-running scan (that
429 * we have one at all will be verified by checking
430 * local->scan_req next), but not to complete it
431 * successfully.
432 */
433 if (WARN_ON(!local->scanning && !aborted))
434 aborted = true;
435
436 if (WARN_ON(!local->scan_req))
437 return;
438
439 scan_sdata = rcu_dereference_protected(local->scan_sdata,
440 lockdep_is_held(&local->mtx));
441
442 if (hw_scan && !aborted &&
443 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
444 ieee80211_prep_hw_scan(scan_sdata)) {
445 int rc;
446
447 rc = drv_hw_scan(local,
448 rcu_dereference_protected(local->scan_sdata,
449 lockdep_is_held(&local->mtx)),
450 local->hw_scan_req);
451
452 if (rc == 0)
453 return;
454
455 /* HW scan failed and is going to be reported as aborted,
456 * so clear old scan info.
457 */
458 memset(&local->scan_info, 0, sizeof(local->scan_info));
459 aborted = true;
460 }
461
462 kfree(local->hw_scan_req);
463 local->hw_scan_req = NULL;
464
465 scan_req = rcu_dereference_protected(local->scan_req,
466 lockdep_is_held(&local->mtx));
467
468 RCU_INIT_POINTER(local->scan_req, NULL);
469 RCU_INIT_POINTER(local->scan_sdata, NULL);
470
471 local->scanning = 0;
472 local->scan_chandef.chan = NULL;
473
474 synchronize_rcu();
475
476 if (scan_req != local->int_scan_req) {
477 local->scan_info.aborted = aborted;
478 cfg80211_scan_done(scan_req, &local->scan_info);
479 }
480
481 /* Set power back to normal operating levels. */
482 ieee80211_hw_config(local, 0);
483
484 if (!hw_scan) {
485 ieee80211_configure_filter(local);
486 drv_sw_scan_complete(local, scan_sdata);
487 ieee80211_offchannel_return(local);
488 }
489
490 ieee80211_recalc_idle(local);
491
492 ieee80211_mlme_notify_scan_completed(local);
493 ieee80211_ibss_notify_scan_completed(local);
494
495 /* Requeue all the work that might have been ignored while
496 * the scan was in progress; if there was none this will
497 * just be a no-op for the particular interface.
498 */
499 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
500 if (ieee80211_sdata_running(sdata))
501 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
502 }
503
504 if (was_scanning)
505 ieee80211_start_next_roc(local);
506 }
507
ieee80211_scan_completed(struct ieee80211_hw * hw,struct cfg80211_scan_info * info)508 void ieee80211_scan_completed(struct ieee80211_hw *hw,
509 struct cfg80211_scan_info *info)
510 {
511 struct ieee80211_local *local = hw_to_local(hw);
512
513 trace_api_scan_completed(local, info->aborted);
514
515 set_bit(SCAN_COMPLETED, &local->scanning);
516 if (info->aborted)
517 set_bit(SCAN_ABORTED, &local->scanning);
518
519 memcpy(&local->scan_info, info, sizeof(*info));
520
521 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
522 }
523 EXPORT_SYMBOL(ieee80211_scan_completed);
524
ieee80211_start_sw_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)525 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
526 struct ieee80211_sub_if_data *sdata)
527 {
528 /* Software scan is not supported in multi-channel cases */
529 if (local->use_chanctx)
530 return -EOPNOTSUPP;
531
532 /*
533 * Hardware/driver doesn't support hw_scan, so use software
534 * scanning instead. First send a nullfunc frame with power save
535 * bit on so that AP will buffer the frames for us while we are not
536 * listening, then send probe requests to each channel and wait for
537 * the responses. After all channels are scanned, tune back to the
538 * original channel and send a nullfunc frame with power save bit
539 * off to trigger the AP to send us all the buffered frames.
540 *
541 * Note that while local->sw_scanning is true everything else but
542 * nullfunc frames and probe requests will be dropped in
543 * ieee80211_tx_h_check_assoc().
544 */
545 drv_sw_scan_start(local, sdata, local->scan_addr);
546
547 local->leave_oper_channel_time = jiffies;
548 local->next_scan_state = SCAN_DECISION;
549 local->scan_channel_idx = 0;
550
551 ieee80211_offchannel_stop_vifs(local);
552
553 /* ensure nullfunc is transmitted before leaving operating channel */
554 ieee80211_flush_queues(local, NULL, false);
555
556 ieee80211_configure_filter(local);
557
558 /* We need to set power level at maximum rate for scanning. */
559 ieee80211_hw_config(local, 0);
560
561 ieee80211_queue_delayed_work(&local->hw,
562 &local->scan_work, 0);
563
564 return 0;
565 }
566
__ieee80211_can_leave_ch(struct ieee80211_sub_if_data * sdata)567 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
568 {
569 struct ieee80211_local *local = sdata->local;
570 struct ieee80211_sub_if_data *sdata_iter;
571
572 if (!ieee80211_is_radar_required(local))
573 return true;
574
575 if (!regulatory_pre_cac_allowed(local->hw.wiphy))
576 return false;
577
578 mutex_lock(&local->iflist_mtx);
579 list_for_each_entry(sdata_iter, &local->interfaces, list) {
580 if (sdata_iter->wdev.cac_started) {
581 mutex_unlock(&local->iflist_mtx);
582 return false;
583 }
584 }
585 mutex_unlock(&local->iflist_mtx);
586
587 return true;
588 }
589
ieee80211_can_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)590 static bool ieee80211_can_scan(struct ieee80211_local *local,
591 struct ieee80211_sub_if_data *sdata)
592 {
593 if (!__ieee80211_can_leave_ch(sdata))
594 return false;
595
596 if (!list_empty(&local->roc_list))
597 return false;
598
599 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
600 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
601 return false;
602
603 return true;
604 }
605
ieee80211_run_deferred_scan(struct ieee80211_local * local)606 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
607 {
608 lockdep_assert_held(&local->mtx);
609
610 if (!local->scan_req || local->scanning)
611 return;
612
613 if (!ieee80211_can_scan(local,
614 rcu_dereference_protected(
615 local->scan_sdata,
616 lockdep_is_held(&local->mtx))))
617 return;
618
619 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
620 round_jiffies_relative(0));
621 }
622
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)623 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
624 const u8 *src, const u8 *dst,
625 const u8 *ssid, size_t ssid_len,
626 const u8 *ie, size_t ie_len,
627 u32 ratemask, u32 flags, u32 tx_flags,
628 struct ieee80211_channel *channel)
629 {
630 struct sk_buff *skb;
631
632 skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
633 ssid, ssid_len,
634 ie, ie_len, flags);
635
636 if (skb) {
637 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
638 struct ieee80211_hdr *hdr = (void *)skb->data;
639 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
640 u16 sn = get_random_u32();
641
642 info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
643 hdr->seq_ctrl =
644 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
645 }
646 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
647 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
648 }
649 }
650
ieee80211_scan_state_send_probe(struct ieee80211_local * local,unsigned long * next_delay)651 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
652 unsigned long *next_delay)
653 {
654 int i;
655 struct ieee80211_sub_if_data *sdata;
656 struct cfg80211_scan_request *scan_req;
657 enum nl80211_band band = local->hw.conf.chandef.chan->band;
658 u32 flags = 0, tx_flags;
659
660 scan_req = rcu_dereference_protected(local->scan_req,
661 lockdep_is_held(&local->mtx));
662
663 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
664 if (scan_req->no_cck)
665 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
666 if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
667 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
668 if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
669 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
670
671 sdata = rcu_dereference_protected(local->scan_sdata,
672 lockdep_is_held(&local->mtx));
673
674 for (i = 0; i < scan_req->n_ssids; i++)
675 ieee80211_send_scan_probe_req(
676 sdata, local->scan_addr, scan_req->bssid,
677 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
678 scan_req->ie, scan_req->ie_len,
679 scan_req->rates[band], flags,
680 tx_flags, local->hw.conf.chandef.chan);
681
682 /*
683 * After sending probe requests, wait for probe responses
684 * on the channel.
685 */
686 *next_delay = IEEE80211_CHANNEL_TIME;
687 local->next_scan_state = SCAN_DECISION;
688 }
689
__ieee80211_start_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)690 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
691 struct cfg80211_scan_request *req)
692 {
693 struct ieee80211_local *local = sdata->local;
694 bool hw_scan = local->ops->hw_scan;
695 int rc;
696
697 lockdep_assert_held(&local->mtx);
698
699 if (local->scan_req)
700 return -EBUSY;
701
702 if (!__ieee80211_can_leave_ch(sdata))
703 return -EBUSY;
704
705 if (!ieee80211_can_scan(local, sdata)) {
706 /* wait for the work to finish/time out */
707 rcu_assign_pointer(local->scan_req, req);
708 rcu_assign_pointer(local->scan_sdata, sdata);
709 return 0;
710 }
711
712 again:
713 if (hw_scan) {
714 u8 *ies;
715
716 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
717
718 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
719 int i, n_bands = 0;
720 u8 bands_counted = 0;
721
722 for (i = 0; i < req->n_channels; i++) {
723 if (bands_counted & BIT(req->channels[i]->band))
724 continue;
725 bands_counted |= BIT(req->channels[i]->band);
726 n_bands++;
727 }
728
729 local->hw_scan_ies_bufsize *= n_bands;
730 }
731
732 local->hw_scan_req = kmalloc(
733 sizeof(*local->hw_scan_req) +
734 req->n_channels * sizeof(req->channels[0]) +
735 local->hw_scan_ies_bufsize, GFP_KERNEL);
736 if (!local->hw_scan_req)
737 return -ENOMEM;
738
739 local->hw_scan_req->req.ssids = req->ssids;
740 local->hw_scan_req->req.n_ssids = req->n_ssids;
741 ies = (u8 *)local->hw_scan_req +
742 sizeof(*local->hw_scan_req) +
743 req->n_channels * sizeof(req->channels[0]);
744 local->hw_scan_req->req.ie = ies;
745 local->hw_scan_req->req.flags = req->flags;
746 eth_broadcast_addr(local->hw_scan_req->req.bssid);
747 local->hw_scan_req->req.duration = req->duration;
748 local->hw_scan_req->req.duration_mandatory =
749 req->duration_mandatory;
750
751 local->hw_scan_band = 0;
752 local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
753 local->hw_scan_req->req.scan_6ghz_params =
754 req->scan_6ghz_params;
755 local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
756
757 /*
758 * After allocating local->hw_scan_req, we must
759 * go through until ieee80211_prep_hw_scan(), so
760 * anything that might be changed here and leave
761 * this function early must not go after this
762 * allocation.
763 */
764 }
765
766 rcu_assign_pointer(local->scan_req, req);
767 rcu_assign_pointer(local->scan_sdata, sdata);
768
769 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
770 get_random_mask_addr(local->scan_addr,
771 req->mac_addr,
772 req->mac_addr_mask);
773 else
774 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
775
776 if (hw_scan) {
777 __set_bit(SCAN_HW_SCANNING, &local->scanning);
778 } else if ((req->n_channels == 1) &&
779 (req->channels[0] == local->_oper_chandef.chan)) {
780 /*
781 * If we are scanning only on the operating channel
782 * then we do not need to stop normal activities
783 */
784 unsigned long next_delay;
785
786 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
787
788 ieee80211_recalc_idle(local);
789
790 /* Notify driver scan is starting, keep order of operations
791 * same as normal software scan, in case that matters. */
792 drv_sw_scan_start(local, sdata, local->scan_addr);
793
794 ieee80211_configure_filter(local); /* accept probe-responses */
795
796 /* We need to ensure power level is at max for scanning. */
797 ieee80211_hw_config(local, 0);
798
799 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
800 IEEE80211_CHAN_RADAR)) ||
801 !req->n_ssids) {
802 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
803 if (req->n_ssids)
804 set_bit(SCAN_BEACON_WAIT, &local->scanning);
805 } else {
806 ieee80211_scan_state_send_probe(local, &next_delay);
807 next_delay = IEEE80211_CHANNEL_TIME;
808 }
809
810 /* Now, just wait a bit and we are all done! */
811 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
812 next_delay);
813 return 0;
814 } else {
815 /* Do normal software scan */
816 __set_bit(SCAN_SW_SCANNING, &local->scanning);
817 }
818
819 ieee80211_recalc_idle(local);
820
821 if (hw_scan) {
822 WARN_ON(!ieee80211_prep_hw_scan(sdata));
823 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
824 } else {
825 rc = ieee80211_start_sw_scan(local, sdata);
826 }
827
828 if (rc) {
829 kfree(local->hw_scan_req);
830 local->hw_scan_req = NULL;
831 local->scanning = 0;
832
833 ieee80211_recalc_idle(local);
834
835 local->scan_req = NULL;
836 RCU_INIT_POINTER(local->scan_sdata, NULL);
837 }
838
839 if (hw_scan && rc == 1) {
840 /*
841 * we can't fall back to software for P2P-GO
842 * as it must update NoA etc.
843 */
844 if (ieee80211_vif_type_p2p(&sdata->vif) ==
845 NL80211_IFTYPE_P2P_GO)
846 return -EOPNOTSUPP;
847 hw_scan = false;
848 goto again;
849 }
850
851 return rc;
852 }
853
854 static unsigned long
ieee80211_scan_get_channel_time(struct ieee80211_channel * chan)855 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
856 {
857 /*
858 * TODO: channel switching also consumes quite some time,
859 * add that delay as well to get a better estimation
860 */
861 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
862 return IEEE80211_PASSIVE_CHANNEL_TIME;
863 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
864 }
865
ieee80211_scan_state_decision(struct ieee80211_local * local,unsigned long * next_delay)866 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
867 unsigned long *next_delay)
868 {
869 bool associated = false;
870 bool tx_empty = true;
871 bool bad_latency;
872 struct ieee80211_sub_if_data *sdata;
873 struct ieee80211_channel *next_chan;
874 enum mac80211_scan_state next_scan_state;
875 struct cfg80211_scan_request *scan_req;
876
877 /*
878 * check if at least one STA interface is associated,
879 * check if at least one STA interface has pending tx frames
880 * and grab the lowest used beacon interval
881 */
882 mutex_lock(&local->iflist_mtx);
883 list_for_each_entry(sdata, &local->interfaces, list) {
884 if (!ieee80211_sdata_running(sdata))
885 continue;
886
887 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
888 if (sdata->u.mgd.associated) {
889 associated = true;
890
891 if (!qdisc_all_tx_empty(sdata->dev)) {
892 tx_empty = false;
893 break;
894 }
895 }
896 }
897 }
898 mutex_unlock(&local->iflist_mtx);
899
900 scan_req = rcu_dereference_protected(local->scan_req,
901 lockdep_is_held(&local->mtx));
902
903 next_chan = scan_req->channels[local->scan_channel_idx];
904
905 /*
906 * we're currently scanning a different channel, let's
907 * see if we can scan another channel without interfering
908 * with the current traffic situation.
909 *
910 * Keep good latency, do not stay off-channel more than 125 ms.
911 */
912
913 bad_latency = time_after(jiffies +
914 ieee80211_scan_get_channel_time(next_chan),
915 local->leave_oper_channel_time + HZ / 8);
916
917 if (associated && !tx_empty) {
918 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
919 next_scan_state = SCAN_ABORT;
920 else
921 next_scan_state = SCAN_SUSPEND;
922 } else if (associated && bad_latency) {
923 next_scan_state = SCAN_SUSPEND;
924 } else {
925 next_scan_state = SCAN_SET_CHANNEL;
926 }
927
928 local->next_scan_state = next_scan_state;
929
930 *next_delay = 0;
931 }
932
ieee80211_scan_state_set_channel(struct ieee80211_local * local,unsigned long * next_delay)933 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
934 unsigned long *next_delay)
935 {
936 int skip;
937 struct ieee80211_channel *chan;
938 enum nl80211_bss_scan_width oper_scan_width;
939 struct cfg80211_scan_request *scan_req;
940
941 scan_req = rcu_dereference_protected(local->scan_req,
942 lockdep_is_held(&local->mtx));
943
944 skip = 0;
945 chan = scan_req->channels[local->scan_channel_idx];
946
947 local->scan_chandef.chan = chan;
948 local->scan_chandef.center_freq1 = chan->center_freq;
949 local->scan_chandef.freq1_offset = chan->freq_offset;
950 local->scan_chandef.center_freq2 = 0;
951
952 /* For scanning on the S1G band, ignore scan_width (which is constant
953 * across all channels) for now since channel width is specific to each
954 * channel. Detect the required channel width here and likely revisit
955 * later. Maybe scan_width could be used to build the channel scan list?
956 */
957 if (chan->band == NL80211_BAND_S1GHZ) {
958 local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
959 goto set_channel;
960 }
961
962 switch (scan_req->scan_width) {
963 case NL80211_BSS_CHAN_WIDTH_5:
964 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
965 break;
966 case NL80211_BSS_CHAN_WIDTH_10:
967 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
968 break;
969 default:
970 case NL80211_BSS_CHAN_WIDTH_20:
971 /* If scanning on oper channel, use whatever channel-type
972 * is currently in use.
973 */
974 oper_scan_width = cfg80211_chandef_to_scan_width(
975 &local->_oper_chandef);
976 if (chan == local->_oper_chandef.chan &&
977 oper_scan_width == scan_req->scan_width)
978 local->scan_chandef = local->_oper_chandef;
979 else
980 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
981 break;
982 case NL80211_BSS_CHAN_WIDTH_1:
983 case NL80211_BSS_CHAN_WIDTH_2:
984 /* shouldn't get here, S1G handled above */
985 WARN_ON(1);
986 break;
987 }
988
989 set_channel:
990 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
991 skip = 1;
992
993 /* advance state machine to next channel/band */
994 local->scan_channel_idx++;
995
996 if (skip) {
997 /* if we skip this channel return to the decision state */
998 local->next_scan_state = SCAN_DECISION;
999 return;
1000 }
1001
1002 /*
1003 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
1004 * (which unfortunately doesn't say _why_ step a) is done,
1005 * but it waits for the probe delay or until a frame is
1006 * received - and the received frame would update the NAV).
1007 * For now, we do not support waiting until a frame is
1008 * received.
1009 *
1010 * In any case, it is not necessary for a passive scan.
1011 */
1012 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
1013 !scan_req->n_ssids) {
1014 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
1015 local->next_scan_state = SCAN_DECISION;
1016 if (scan_req->n_ssids)
1017 set_bit(SCAN_BEACON_WAIT, &local->scanning);
1018 return;
1019 }
1020
1021 /* active scan, send probes */
1022 *next_delay = IEEE80211_PROBE_DELAY;
1023 local->next_scan_state = SCAN_SEND_PROBE;
1024 }
1025
ieee80211_scan_state_suspend(struct ieee80211_local * local,unsigned long * next_delay)1026 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1027 unsigned long *next_delay)
1028 {
1029 /* switch back to the operating channel */
1030 local->scan_chandef.chan = NULL;
1031 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
1032
1033 /* disable PS */
1034 ieee80211_offchannel_return(local);
1035
1036 *next_delay = HZ / 5;
1037 /* afterwards, resume scan & go to next channel */
1038 local->next_scan_state = SCAN_RESUME;
1039 }
1040
ieee80211_scan_state_resume(struct ieee80211_local * local,unsigned long * next_delay)1041 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1042 unsigned long *next_delay)
1043 {
1044 ieee80211_offchannel_stop_vifs(local);
1045
1046 if (local->ops->flush) {
1047 ieee80211_flush_queues(local, NULL, false);
1048 *next_delay = 0;
1049 } else
1050 *next_delay = HZ / 10;
1051
1052 /* remember when we left the operating channel */
1053 local->leave_oper_channel_time = jiffies;
1054
1055 /* advance to the next channel to be scanned */
1056 local->next_scan_state = SCAN_SET_CHANNEL;
1057 }
1058
ieee80211_scan_work(struct work_struct * work)1059 void ieee80211_scan_work(struct work_struct *work)
1060 {
1061 struct ieee80211_local *local =
1062 container_of(work, struct ieee80211_local, scan_work.work);
1063 struct ieee80211_sub_if_data *sdata;
1064 struct cfg80211_scan_request *scan_req;
1065 unsigned long next_delay = 0;
1066 bool aborted;
1067
1068 mutex_lock(&local->mtx);
1069
1070 if (!ieee80211_can_run_worker(local)) {
1071 aborted = true;
1072 goto out_complete;
1073 }
1074
1075 sdata = rcu_dereference_protected(local->scan_sdata,
1076 lockdep_is_held(&local->mtx));
1077 scan_req = rcu_dereference_protected(local->scan_req,
1078 lockdep_is_held(&local->mtx));
1079
1080 /* When scanning on-channel, the first-callback means completed. */
1081 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1082 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1083 goto out_complete;
1084 }
1085
1086 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1087 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1088 goto out_complete;
1089 }
1090
1091 if (!sdata || !scan_req)
1092 goto out;
1093
1094 if (!local->scanning) {
1095 int rc;
1096
1097 RCU_INIT_POINTER(local->scan_req, NULL);
1098 RCU_INIT_POINTER(local->scan_sdata, NULL);
1099
1100 rc = __ieee80211_start_scan(sdata, scan_req);
1101 if (rc) {
1102 /* need to complete scan in cfg80211 */
1103 rcu_assign_pointer(local->scan_req, scan_req);
1104 aborted = true;
1105 goto out_complete;
1106 } else
1107 goto out;
1108 }
1109
1110 clear_bit(SCAN_BEACON_WAIT, &local->scanning);
1111
1112 /*
1113 * as long as no delay is required advance immediately
1114 * without scheduling a new work
1115 */
1116 do {
1117 if (!ieee80211_sdata_running(sdata)) {
1118 aborted = true;
1119 goto out_complete;
1120 }
1121
1122 if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) &&
1123 local->next_scan_state == SCAN_DECISION)
1124 local->next_scan_state = SCAN_SEND_PROBE;
1125
1126 switch (local->next_scan_state) {
1127 case SCAN_DECISION:
1128 /* if no more bands/channels left, complete scan */
1129 if (local->scan_channel_idx >= scan_req->n_channels) {
1130 aborted = false;
1131 goto out_complete;
1132 }
1133 ieee80211_scan_state_decision(local, &next_delay);
1134 break;
1135 case SCAN_SET_CHANNEL:
1136 ieee80211_scan_state_set_channel(local, &next_delay);
1137 break;
1138 case SCAN_SEND_PROBE:
1139 ieee80211_scan_state_send_probe(local, &next_delay);
1140 break;
1141 case SCAN_SUSPEND:
1142 ieee80211_scan_state_suspend(local, &next_delay);
1143 break;
1144 case SCAN_RESUME:
1145 ieee80211_scan_state_resume(local, &next_delay);
1146 break;
1147 case SCAN_ABORT:
1148 aborted = true;
1149 goto out_complete;
1150 }
1151 } while (next_delay == 0);
1152
1153 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
1154 goto out;
1155
1156 out_complete:
1157 __ieee80211_scan_completed(&local->hw, aborted);
1158 out:
1159 mutex_unlock(&local->mtx);
1160 }
1161
ieee80211_request_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)1162 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1163 struct cfg80211_scan_request *req)
1164 {
1165 int res;
1166
1167 mutex_lock(&sdata->local->mtx);
1168 res = __ieee80211_start_scan(sdata, req);
1169 mutex_unlock(&sdata->local->mtx);
1170
1171 return res;
1172 }
1173
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)1174 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1175 const u8 *ssid, u8 ssid_len,
1176 struct ieee80211_channel **channels,
1177 unsigned int n_channels,
1178 enum nl80211_bss_scan_width scan_width)
1179 {
1180 struct ieee80211_local *local = sdata->local;
1181 int ret = -EBUSY, i, n_ch = 0;
1182 enum nl80211_band band;
1183
1184 mutex_lock(&local->mtx);
1185
1186 /* busy scanning */
1187 if (local->scan_req)
1188 goto unlock;
1189
1190 /* fill internal scan request */
1191 if (!channels) {
1192 int max_n;
1193
1194 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1195 if (!local->hw.wiphy->bands[band] ||
1196 band == NL80211_BAND_6GHZ)
1197 continue;
1198
1199 max_n = local->hw.wiphy->bands[band]->n_channels;
1200 for (i = 0; i < max_n; i++) {
1201 struct ieee80211_channel *tmp_ch =
1202 &local->hw.wiphy->bands[band]->channels[i];
1203
1204 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1205 IEEE80211_CHAN_DISABLED))
1206 continue;
1207
1208 local->int_scan_req->channels[n_ch] = tmp_ch;
1209 n_ch++;
1210 }
1211 }
1212
1213 if (WARN_ON_ONCE(n_ch == 0))
1214 goto unlock;
1215
1216 local->int_scan_req->n_channels = n_ch;
1217 } else {
1218 for (i = 0; i < n_channels; i++) {
1219 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1220 IEEE80211_CHAN_DISABLED))
1221 continue;
1222
1223 local->int_scan_req->channels[n_ch] = channels[i];
1224 n_ch++;
1225 }
1226
1227 if (WARN_ON_ONCE(n_ch == 0))
1228 goto unlock;
1229
1230 local->int_scan_req->n_channels = n_ch;
1231 }
1232
1233 local->int_scan_req->ssids = &local->scan_ssid;
1234 local->int_scan_req->n_ssids = 1;
1235 local->int_scan_req->scan_width = scan_width;
1236 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1237 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1238
1239 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1240 unlock:
1241 mutex_unlock(&local->mtx);
1242 return ret;
1243 }
1244
1245 /*
1246 * Only call this function when a scan can't be queued -- under RTNL.
1247 */
ieee80211_scan_cancel(struct ieee80211_local * local)1248 void ieee80211_scan_cancel(struct ieee80211_local *local)
1249 {
1250 /*
1251 * We are canceling software scan, or deferred scan that was not
1252 * yet really started (see __ieee80211_start_scan ).
1253 *
1254 * Regarding hardware scan:
1255 * - we can not call __ieee80211_scan_completed() as when
1256 * SCAN_HW_SCANNING bit is set this function change
1257 * local->hw_scan_req to operate on 5G band, what race with
1258 * driver which can use local->hw_scan_req
1259 *
1260 * - we can not cancel scan_work since driver can schedule it
1261 * by ieee80211_scan_completed(..., true) to finish scan
1262 *
1263 * Hence we only call the cancel_hw_scan() callback, but the low-level
1264 * driver is still responsible for calling ieee80211_scan_completed()
1265 * after the scan was completed/aborted.
1266 */
1267
1268 mutex_lock(&local->mtx);
1269 if (!local->scan_req)
1270 goto out;
1271
1272 /*
1273 * We have a scan running and the driver already reported completion,
1274 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1275 * cancelled.
1276 */
1277 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1278 test_bit(SCAN_COMPLETED, &local->scanning)) {
1279 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1280 goto out;
1281 }
1282
1283 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1284 /*
1285 * Make sure that __ieee80211_scan_completed doesn't trigger a
1286 * scan on another band.
1287 */
1288 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1289 if (local->ops->cancel_hw_scan)
1290 drv_cancel_hw_scan(local,
1291 rcu_dereference_protected(local->scan_sdata,
1292 lockdep_is_held(&local->mtx)));
1293 goto out;
1294 }
1295
1296 /*
1297 * If the work is currently running, it must be blocked on
1298 * the mutex, but we'll set scan_sdata = NULL and it'll
1299 * simply exit once it acquires the mutex.
1300 */
1301 cancel_delayed_work(&local->scan_work);
1302 /* and clean up */
1303 memset(&local->scan_info, 0, sizeof(local->scan_info));
1304 __ieee80211_scan_completed(&local->hw, true);
1305 out:
1306 mutex_unlock(&local->mtx);
1307 }
1308
__ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1309 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1310 struct cfg80211_sched_scan_request *req)
1311 {
1312 struct ieee80211_local *local = sdata->local;
1313 struct ieee80211_scan_ies sched_scan_ies = {};
1314 struct cfg80211_chan_def chandef;
1315 int ret, i, iebufsz, num_bands = 0;
1316 u32 rate_masks[NUM_NL80211_BANDS] = {};
1317 u8 bands_used = 0;
1318 u8 *ie;
1319 u32 flags = 0;
1320
1321 iebufsz = local->scan_ies_len + req->ie_len;
1322
1323 lockdep_assert_held(&local->mtx);
1324
1325 if (!local->ops->sched_scan_start)
1326 return -ENOTSUPP;
1327
1328 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1329 if (local->hw.wiphy->bands[i]) {
1330 bands_used |= BIT(i);
1331 rate_masks[i] = (u32) -1;
1332 num_bands++;
1333 }
1334 }
1335
1336 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1337 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1338
1339 ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1340 if (!ie) {
1341 ret = -ENOMEM;
1342 goto out;
1343 }
1344
1345 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1346
1347 ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1348 &sched_scan_ies, req->ie,
1349 req->ie_len, bands_used, rate_masks, &chandef,
1350 flags);
1351
1352 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1353 if (ret == 0) {
1354 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1355 rcu_assign_pointer(local->sched_scan_req, req);
1356 }
1357
1358 kfree(ie);
1359
1360 out:
1361 if (ret) {
1362 /* Clean in case of failure after HW restart or upon resume. */
1363 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1364 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1365 }
1366
1367 return ret;
1368 }
1369
ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1370 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1371 struct cfg80211_sched_scan_request *req)
1372 {
1373 struct ieee80211_local *local = sdata->local;
1374 int ret;
1375
1376 mutex_lock(&local->mtx);
1377
1378 if (rcu_access_pointer(local->sched_scan_sdata)) {
1379 mutex_unlock(&local->mtx);
1380 return -EBUSY;
1381 }
1382
1383 ret = __ieee80211_request_sched_scan_start(sdata, req);
1384
1385 mutex_unlock(&local->mtx);
1386 return ret;
1387 }
1388
ieee80211_request_sched_scan_stop(struct ieee80211_local * local)1389 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1390 {
1391 struct ieee80211_sub_if_data *sched_scan_sdata;
1392 int ret = -ENOENT;
1393
1394 mutex_lock(&local->mtx);
1395
1396 if (!local->ops->sched_scan_stop) {
1397 ret = -ENOTSUPP;
1398 goto out;
1399 }
1400
1401 /* We don't want to restart sched scan anymore. */
1402 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1403
1404 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1405 lockdep_is_held(&local->mtx));
1406 if (sched_scan_sdata) {
1407 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1408 if (!ret)
1409 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1410 }
1411 out:
1412 mutex_unlock(&local->mtx);
1413
1414 return ret;
1415 }
1416
ieee80211_sched_scan_results(struct ieee80211_hw * hw)1417 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1418 {
1419 struct ieee80211_local *local = hw_to_local(hw);
1420
1421 trace_api_sched_scan_results(local);
1422
1423 cfg80211_sched_scan_results(hw->wiphy, 0);
1424 }
1425 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1426
ieee80211_sched_scan_end(struct ieee80211_local * local)1427 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1428 {
1429 mutex_lock(&local->mtx);
1430
1431 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1432 mutex_unlock(&local->mtx);
1433 return;
1434 }
1435
1436 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1437
1438 /* If sched scan was aborted by the driver. */
1439 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1440
1441 mutex_unlock(&local->mtx);
1442
1443 cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1444 }
1445
ieee80211_sched_scan_stopped_work(struct work_struct * work)1446 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1447 {
1448 struct ieee80211_local *local =
1449 container_of(work, struct ieee80211_local,
1450 sched_scan_stopped_work);
1451
1452 ieee80211_sched_scan_end(local);
1453 }
1454
ieee80211_sched_scan_stopped(struct ieee80211_hw * hw)1455 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1456 {
1457 struct ieee80211_local *local = hw_to_local(hw);
1458
1459 trace_api_sched_scan_stopped(local);
1460
1461 /*
1462 * this shouldn't really happen, so for simplicity
1463 * simply ignore it, and let mac80211 reconfigure
1464 * the sched scan later on.
1465 */
1466 if (local->in_reconfig)
1467 return;
1468
1469 schedule_work(&local->sched_scan_stopped_work);
1470 }
1471 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
1472