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.cfg.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, cbss);
213 if (!elems)
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 bss = (void *)cbss->priv;
222 ieee80211_update_bss_from_elems(local, bss, elems, rx_status, beacon);
223 kfree(elems);
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 elems = ieee802_11_parse_elems(elements, len - baselen, false,
229 non_tx_cbss);
230 if (!elems)
231 continue;
232
233 ieee80211_update_bss_from_elems(local, non_tx_bss, elems,
234 rx_status, beacon);
235 kfree(elems);
236 }
237
238 return bss;
239 }
240
ieee80211_scan_accept_presp(struct ieee80211_sub_if_data * sdata,u32 scan_flags,const u8 * da)241 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
242 u32 scan_flags, const u8 *da)
243 {
244 if (!sdata)
245 return false;
246 /* accept broadcast for OCE */
247 if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
248 is_broadcast_ether_addr(da))
249 return true;
250 if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
251 return true;
252 return ether_addr_equal(da, sdata->vif.addr);
253 }
254
ieee80211_scan_rx(struct ieee80211_local * local,struct sk_buff * skb)255 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
256 {
257 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
258 struct ieee80211_sub_if_data *sdata1, *sdata2;
259 struct ieee80211_mgmt *mgmt = (void *)skb->data;
260 struct ieee80211_bss *bss;
261 struct ieee80211_channel *channel;
262 size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
263 u.probe_resp.variable);
264
265 if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
266 !ieee80211_is_beacon(mgmt->frame_control) &&
267 !ieee80211_is_s1g_beacon(mgmt->frame_control))
268 return;
269
270 if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
271 if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
272 min_hdr_len = offsetof(struct ieee80211_ext,
273 u.s1g_short_beacon.variable);
274 else
275 min_hdr_len = offsetof(struct ieee80211_ext,
276 u.s1g_beacon);
277 }
278
279 if (skb->len < min_hdr_len)
280 return;
281
282 sdata1 = rcu_dereference(local->scan_sdata);
283 sdata2 = rcu_dereference(local->sched_scan_sdata);
284
285 if (likely(!sdata1 && !sdata2))
286 return;
287
288 if (test_and_clear_bit(SCAN_BEACON_WAIT, &local->scanning)) {
289 /*
290 * we were passive scanning because of radar/no-IR, but
291 * the beacon/proberesp rx gives us an opportunity to upgrade
292 * to active scan
293 */
294 set_bit(SCAN_BEACON_DONE, &local->scanning);
295 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
296 }
297
298 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
299 struct cfg80211_scan_request *scan_req;
300 struct cfg80211_sched_scan_request *sched_scan_req;
301 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
302
303 scan_req = rcu_dereference(local->scan_req);
304 sched_scan_req = rcu_dereference(local->sched_scan_req);
305
306 if (scan_req)
307 scan_req_flags = scan_req->flags;
308
309 if (sched_scan_req)
310 sched_scan_req_flags = sched_scan_req->flags;
311
312 /* ignore ProbeResp to foreign address or non-bcast (OCE)
313 * unless scanning with randomised address
314 */
315 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
316 mgmt->da) &&
317 !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
318 mgmt->da))
319 return;
320 }
321
322 channel = ieee80211_get_channel_khz(local->hw.wiphy,
323 ieee80211_rx_status_to_khz(rx_status));
324
325 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
326 return;
327
328 bss = ieee80211_bss_info_update(local, rx_status,
329 mgmt, skb->len,
330 channel);
331 if (bss)
332 ieee80211_rx_bss_put(local, bss);
333 }
334
335 static void
ieee80211_prepare_scan_chandef(struct cfg80211_chan_def * chandef,enum nl80211_bss_scan_width scan_width)336 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
337 enum nl80211_bss_scan_width scan_width)
338 {
339 memset(chandef, 0, sizeof(*chandef));
340 switch (scan_width) {
341 case NL80211_BSS_CHAN_WIDTH_5:
342 chandef->width = NL80211_CHAN_WIDTH_5;
343 break;
344 case NL80211_BSS_CHAN_WIDTH_10:
345 chandef->width = NL80211_CHAN_WIDTH_10;
346 break;
347 default:
348 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
349 break;
350 }
351 }
352
353 /* return false if no more work */
ieee80211_prep_hw_scan(struct ieee80211_sub_if_data * sdata)354 static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
355 {
356 struct ieee80211_local *local = sdata->local;
357 struct cfg80211_scan_request *req;
358 struct cfg80211_chan_def chandef;
359 u8 bands_used = 0;
360 int i, ielen, n_chans;
361 u32 flags = 0;
362
363 req = rcu_dereference_protected(local->scan_req,
364 lockdep_is_held(&local->mtx));
365
366 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
367 return false;
368
369 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
370 for (i = 0; i < req->n_channels; i++) {
371 local->hw_scan_req->req.channels[i] = req->channels[i];
372 bands_used |= BIT(req->channels[i]->band);
373 }
374
375 n_chans = req->n_channels;
376 } else {
377 do {
378 if (local->hw_scan_band == NUM_NL80211_BANDS)
379 return false;
380
381 n_chans = 0;
382
383 for (i = 0; i < req->n_channels; i++) {
384 if (req->channels[i]->band !=
385 local->hw_scan_band)
386 continue;
387 local->hw_scan_req->req.channels[n_chans] =
388 req->channels[i];
389 n_chans++;
390 bands_used |= BIT(req->channels[i]->band);
391 }
392
393 local->hw_scan_band++;
394 } while (!n_chans);
395 }
396
397 local->hw_scan_req->req.n_channels = n_chans;
398 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
399
400 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
401 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
402
403 ielen = ieee80211_build_preq_ies(sdata,
404 (u8 *)local->hw_scan_req->req.ie,
405 local->hw_scan_ies_bufsize,
406 &local->hw_scan_req->ies,
407 req->ie, req->ie_len,
408 bands_used, req->rates, &chandef,
409 flags);
410 local->hw_scan_req->req.ie_len = ielen;
411 local->hw_scan_req->req.no_cck = req->no_cck;
412 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
413 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
414 req->mac_addr_mask);
415 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
416
417 return true;
418 }
419
__ieee80211_scan_completed(struct ieee80211_hw * hw,bool aborted)420 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
421 {
422 struct ieee80211_local *local = hw_to_local(hw);
423 bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
424 bool was_scanning = local->scanning;
425 struct cfg80211_scan_request *scan_req;
426 struct ieee80211_sub_if_data *scan_sdata;
427 struct ieee80211_sub_if_data *sdata;
428
429 lockdep_assert_held(&local->mtx);
430
431 /*
432 * It's ok to abort a not-yet-running scan (that
433 * we have one at all will be verified by checking
434 * local->scan_req next), but not to complete it
435 * successfully.
436 */
437 if (WARN_ON(!local->scanning && !aborted))
438 aborted = true;
439
440 if (WARN_ON(!local->scan_req))
441 return;
442
443 scan_sdata = rcu_dereference_protected(local->scan_sdata,
444 lockdep_is_held(&local->mtx));
445
446 if (hw_scan && !aborted &&
447 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
448 ieee80211_prep_hw_scan(scan_sdata)) {
449 int rc;
450
451 rc = drv_hw_scan(local,
452 rcu_dereference_protected(local->scan_sdata,
453 lockdep_is_held(&local->mtx)),
454 local->hw_scan_req);
455
456 if (rc == 0)
457 return;
458
459 /* HW scan failed and is going to be reported as aborted,
460 * so clear old scan info.
461 */
462 memset(&local->scan_info, 0, sizeof(local->scan_info));
463 aborted = true;
464 }
465
466 kfree(local->hw_scan_req);
467 local->hw_scan_req = NULL;
468
469 scan_req = rcu_dereference_protected(local->scan_req,
470 lockdep_is_held(&local->mtx));
471
472 RCU_INIT_POINTER(local->scan_req, NULL);
473 RCU_INIT_POINTER(local->scan_sdata, NULL);
474
475 local->scanning = 0;
476 local->scan_chandef.chan = NULL;
477
478 synchronize_rcu();
479
480 if (scan_req != local->int_scan_req) {
481 local->scan_info.aborted = aborted;
482 cfg80211_scan_done(scan_req, &local->scan_info);
483 }
484
485 /* Set power back to normal operating levels. */
486 ieee80211_hw_config(local, 0);
487
488 if (!hw_scan && was_scanning) {
489 ieee80211_configure_filter(local);
490 drv_sw_scan_complete(local, scan_sdata);
491 ieee80211_offchannel_return(local);
492 }
493
494 ieee80211_recalc_idle(local);
495
496 ieee80211_mlme_notify_scan_completed(local);
497 ieee80211_ibss_notify_scan_completed(local);
498
499 /* Requeue all the work that might have been ignored while
500 * the scan was in progress; if there was none this will
501 * just be a no-op for the particular interface.
502 */
503 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
504 if (ieee80211_sdata_running(sdata))
505 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
506 }
507
508 if (was_scanning)
509 ieee80211_start_next_roc(local);
510 }
511
ieee80211_scan_completed(struct ieee80211_hw * hw,struct cfg80211_scan_info * info)512 void ieee80211_scan_completed(struct ieee80211_hw *hw,
513 struct cfg80211_scan_info *info)
514 {
515 struct ieee80211_local *local = hw_to_local(hw);
516
517 trace_api_scan_completed(local, info->aborted);
518
519 set_bit(SCAN_COMPLETED, &local->scanning);
520 if (info->aborted)
521 set_bit(SCAN_ABORTED, &local->scanning);
522
523 memcpy(&local->scan_info, info, sizeof(*info));
524
525 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
526 }
527 EXPORT_SYMBOL(ieee80211_scan_completed);
528
ieee80211_start_sw_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)529 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
530 struct ieee80211_sub_if_data *sdata)
531 {
532 /* Software scan is not supported in multi-channel cases */
533 if (local->use_chanctx)
534 return -EOPNOTSUPP;
535
536 /*
537 * Hardware/driver doesn't support hw_scan, so use software
538 * scanning instead. First send a nullfunc frame with power save
539 * bit on so that AP will buffer the frames for us while we are not
540 * listening, then send probe requests to each channel and wait for
541 * the responses. After all channels are scanned, tune back to the
542 * original channel and send a nullfunc frame with power save bit
543 * off to trigger the AP to send us all the buffered frames.
544 *
545 * Note that while local->sw_scanning is true everything else but
546 * nullfunc frames and probe requests will be dropped in
547 * ieee80211_tx_h_check_assoc().
548 */
549 drv_sw_scan_start(local, sdata, local->scan_addr);
550
551 local->leave_oper_channel_time = jiffies;
552 local->next_scan_state = SCAN_DECISION;
553 local->scan_channel_idx = 0;
554
555 ieee80211_offchannel_stop_vifs(local);
556
557 /* ensure nullfunc is transmitted before leaving operating channel */
558 ieee80211_flush_queues(local, NULL, false);
559
560 ieee80211_configure_filter(local);
561
562 /* We need to set power level at maximum rate for scanning. */
563 ieee80211_hw_config(local, 0);
564
565 ieee80211_queue_delayed_work(&local->hw,
566 &local->scan_work, 0);
567
568 return 0;
569 }
570
__ieee80211_can_leave_ch(struct ieee80211_sub_if_data * sdata)571 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
572 {
573 struct ieee80211_local *local = sdata->local;
574 struct ieee80211_sub_if_data *sdata_iter;
575
576 if (!ieee80211_is_radar_required(local))
577 return true;
578
579 if (!regulatory_pre_cac_allowed(local->hw.wiphy))
580 return false;
581
582 mutex_lock(&local->iflist_mtx);
583 list_for_each_entry(sdata_iter, &local->interfaces, list) {
584 if (sdata_iter->wdev.cac_started) {
585 mutex_unlock(&local->iflist_mtx);
586 return false;
587 }
588 }
589 mutex_unlock(&local->iflist_mtx);
590
591 return true;
592 }
593
ieee80211_can_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)594 static bool ieee80211_can_scan(struct ieee80211_local *local,
595 struct ieee80211_sub_if_data *sdata)
596 {
597 if (!__ieee80211_can_leave_ch(sdata))
598 return false;
599
600 if (!list_empty(&local->roc_list))
601 return false;
602
603 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
604 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
605 return false;
606
607 return true;
608 }
609
ieee80211_run_deferred_scan(struct ieee80211_local * local)610 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
611 {
612 lockdep_assert_held(&local->mtx);
613
614 if (!local->scan_req || local->scanning)
615 return;
616
617 if (!ieee80211_can_scan(local,
618 rcu_dereference_protected(
619 local->scan_sdata,
620 lockdep_is_held(&local->mtx))))
621 return;
622
623 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
624 round_jiffies_relative(0));
625 }
626
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)627 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
628 const u8 *src, const u8 *dst,
629 const u8 *ssid, size_t ssid_len,
630 const u8 *ie, size_t ie_len,
631 u32 ratemask, u32 flags, u32 tx_flags,
632 struct ieee80211_channel *channel)
633 {
634 struct sk_buff *skb;
635
636 skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
637 ssid, ssid_len,
638 ie, ie_len, flags);
639
640 if (skb) {
641 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
642 struct ieee80211_hdr *hdr = (void *)skb->data;
643 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
644 u16 sn = get_random_u16();
645
646 info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
647 hdr->seq_ctrl =
648 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
649 }
650 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
651 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
652 }
653 }
654
ieee80211_scan_state_send_probe(struct ieee80211_local * local,unsigned long * next_delay)655 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
656 unsigned long *next_delay)
657 {
658 int i;
659 struct ieee80211_sub_if_data *sdata;
660 struct cfg80211_scan_request *scan_req;
661 enum nl80211_band band = local->hw.conf.chandef.chan->band;
662 u32 flags = 0, tx_flags;
663
664 scan_req = rcu_dereference_protected(local->scan_req,
665 lockdep_is_held(&local->mtx));
666
667 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
668 if (scan_req->no_cck)
669 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
670 if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
671 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
672 if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
673 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
674
675 sdata = rcu_dereference_protected(local->scan_sdata,
676 lockdep_is_held(&local->mtx));
677
678 for (i = 0; i < scan_req->n_ssids; i++)
679 ieee80211_send_scan_probe_req(
680 sdata, local->scan_addr, scan_req->bssid,
681 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
682 scan_req->ie, scan_req->ie_len,
683 scan_req->rates[band], flags,
684 tx_flags, local->hw.conf.chandef.chan);
685
686 /*
687 * After sending probe requests, wait for probe responses
688 * on the channel.
689 */
690 *next_delay = IEEE80211_CHANNEL_TIME;
691 local->next_scan_state = SCAN_DECISION;
692 }
693
__ieee80211_start_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)694 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
695 struct cfg80211_scan_request *req)
696 {
697 struct ieee80211_local *local = sdata->local;
698 bool hw_scan = local->ops->hw_scan;
699 int rc;
700
701 lockdep_assert_held(&local->mtx);
702
703 if (local->scan_req)
704 return -EBUSY;
705
706 if (!__ieee80211_can_leave_ch(sdata))
707 return -EBUSY;
708
709 if (!ieee80211_can_scan(local, sdata)) {
710 /* wait for the work to finish/time out */
711 rcu_assign_pointer(local->scan_req, req);
712 rcu_assign_pointer(local->scan_sdata, sdata);
713 return 0;
714 }
715
716 again:
717 if (hw_scan) {
718 u8 *ies;
719
720 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
721
722 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
723 int i, n_bands = 0;
724 u8 bands_counted = 0;
725
726 for (i = 0; i < req->n_channels; i++) {
727 if (bands_counted & BIT(req->channels[i]->band))
728 continue;
729 bands_counted |= BIT(req->channels[i]->band);
730 n_bands++;
731 }
732
733 local->hw_scan_ies_bufsize *= n_bands;
734 }
735
736 local->hw_scan_req = kmalloc(
737 sizeof(*local->hw_scan_req) +
738 req->n_channels * sizeof(req->channels[0]) +
739 local->hw_scan_ies_bufsize, GFP_KERNEL);
740 if (!local->hw_scan_req)
741 return -ENOMEM;
742
743 local->hw_scan_req->req.ssids = req->ssids;
744 local->hw_scan_req->req.n_ssids = req->n_ssids;
745 ies = (u8 *)local->hw_scan_req +
746 sizeof(*local->hw_scan_req) +
747 req->n_channels * sizeof(req->channels[0]);
748 local->hw_scan_req->req.ie = ies;
749 local->hw_scan_req->req.flags = req->flags;
750 eth_broadcast_addr(local->hw_scan_req->req.bssid);
751 local->hw_scan_req->req.duration = req->duration;
752 local->hw_scan_req->req.duration_mandatory =
753 req->duration_mandatory;
754
755 local->hw_scan_band = 0;
756 local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
757 local->hw_scan_req->req.scan_6ghz_params =
758 req->scan_6ghz_params;
759 local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
760
761 /*
762 * After allocating local->hw_scan_req, we must
763 * go through until ieee80211_prep_hw_scan(), so
764 * anything that might be changed here and leave
765 * this function early must not go after this
766 * allocation.
767 */
768 }
769
770 rcu_assign_pointer(local->scan_req, req);
771 rcu_assign_pointer(local->scan_sdata, sdata);
772
773 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
774 get_random_mask_addr(local->scan_addr,
775 req->mac_addr,
776 req->mac_addr_mask);
777 else
778 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
779
780 if (hw_scan) {
781 __set_bit(SCAN_HW_SCANNING, &local->scanning);
782 } else if ((req->n_channels == 1) &&
783 (req->channels[0] == local->_oper_chandef.chan)) {
784 /*
785 * If we are scanning only on the operating channel
786 * then we do not need to stop normal activities
787 */
788 unsigned long next_delay;
789
790 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
791
792 ieee80211_recalc_idle(local);
793
794 /* Notify driver scan is starting, keep order of operations
795 * same as normal software scan, in case that matters. */
796 drv_sw_scan_start(local, sdata, local->scan_addr);
797
798 ieee80211_configure_filter(local); /* accept probe-responses */
799
800 /* We need to ensure power level is at max for scanning. */
801 ieee80211_hw_config(local, 0);
802
803 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
804 IEEE80211_CHAN_RADAR)) ||
805 !req->n_ssids) {
806 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
807 if (req->n_ssids)
808 set_bit(SCAN_BEACON_WAIT, &local->scanning);
809 } else {
810 ieee80211_scan_state_send_probe(local, &next_delay);
811 next_delay = IEEE80211_CHANNEL_TIME;
812 }
813
814 /* Now, just wait a bit and we are all done! */
815 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
816 next_delay);
817 return 0;
818 } else {
819 /* Do normal software scan */
820 __set_bit(SCAN_SW_SCANNING, &local->scanning);
821 }
822
823 ieee80211_recalc_idle(local);
824
825 if (hw_scan) {
826 WARN_ON(!ieee80211_prep_hw_scan(sdata));
827 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
828 } else {
829 rc = ieee80211_start_sw_scan(local, sdata);
830 }
831
832 if (rc) {
833 kfree(local->hw_scan_req);
834 local->hw_scan_req = NULL;
835 local->scanning = 0;
836
837 ieee80211_recalc_idle(local);
838
839 local->scan_req = NULL;
840 RCU_INIT_POINTER(local->scan_sdata, NULL);
841 }
842
843 if (hw_scan && rc == 1) {
844 /*
845 * we can't fall back to software for P2P-GO
846 * as it must update NoA etc.
847 */
848 if (ieee80211_vif_type_p2p(&sdata->vif) ==
849 NL80211_IFTYPE_P2P_GO)
850 return -EOPNOTSUPP;
851 hw_scan = false;
852 goto again;
853 }
854
855 return rc;
856 }
857
858 static unsigned long
ieee80211_scan_get_channel_time(struct ieee80211_channel * chan)859 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
860 {
861 /*
862 * TODO: channel switching also consumes quite some time,
863 * add that delay as well to get a better estimation
864 */
865 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
866 return IEEE80211_PASSIVE_CHANNEL_TIME;
867 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
868 }
869
ieee80211_scan_state_decision(struct ieee80211_local * local,unsigned long * next_delay)870 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
871 unsigned long *next_delay)
872 {
873 bool associated = false;
874 bool tx_empty = true;
875 bool bad_latency;
876 struct ieee80211_sub_if_data *sdata;
877 struct ieee80211_channel *next_chan;
878 enum mac80211_scan_state next_scan_state;
879 struct cfg80211_scan_request *scan_req;
880
881 /*
882 * check if at least one STA interface is associated,
883 * check if at least one STA interface has pending tx frames
884 * and grab the lowest used beacon interval
885 */
886 mutex_lock(&local->iflist_mtx);
887 list_for_each_entry(sdata, &local->interfaces, list) {
888 if (!ieee80211_sdata_running(sdata))
889 continue;
890
891 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
892 if (sdata->u.mgd.associated) {
893 associated = true;
894
895 if (!qdisc_all_tx_empty(sdata->dev)) {
896 tx_empty = false;
897 break;
898 }
899 }
900 }
901 }
902 mutex_unlock(&local->iflist_mtx);
903
904 scan_req = rcu_dereference_protected(local->scan_req,
905 lockdep_is_held(&local->mtx));
906
907 next_chan = scan_req->channels[local->scan_channel_idx];
908
909 /*
910 * we're currently scanning a different channel, let's
911 * see if we can scan another channel without interfering
912 * with the current traffic situation.
913 *
914 * Keep good latency, do not stay off-channel more than 125 ms.
915 */
916
917 bad_latency = time_after(jiffies +
918 ieee80211_scan_get_channel_time(next_chan),
919 local->leave_oper_channel_time + HZ / 8);
920
921 if (associated && !tx_empty) {
922 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
923 next_scan_state = SCAN_ABORT;
924 else
925 next_scan_state = SCAN_SUSPEND;
926 } else if (associated && bad_latency) {
927 next_scan_state = SCAN_SUSPEND;
928 } else {
929 next_scan_state = SCAN_SET_CHANNEL;
930 }
931
932 local->next_scan_state = next_scan_state;
933
934 *next_delay = 0;
935 }
936
ieee80211_scan_state_set_channel(struct ieee80211_local * local,unsigned long * next_delay)937 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
938 unsigned long *next_delay)
939 {
940 int skip;
941 struct ieee80211_channel *chan;
942 enum nl80211_bss_scan_width oper_scan_width;
943 struct cfg80211_scan_request *scan_req;
944
945 scan_req = rcu_dereference_protected(local->scan_req,
946 lockdep_is_held(&local->mtx));
947
948 skip = 0;
949 chan = scan_req->channels[local->scan_channel_idx];
950
951 local->scan_chandef.chan = chan;
952 local->scan_chandef.center_freq1 = chan->center_freq;
953 local->scan_chandef.freq1_offset = chan->freq_offset;
954 local->scan_chandef.center_freq2 = 0;
955
956 /* For scanning on the S1G band, ignore scan_width (which is constant
957 * across all channels) for now since channel width is specific to each
958 * channel. Detect the required channel width here and likely revisit
959 * later. Maybe scan_width could be used to build the channel scan list?
960 */
961 if (chan->band == NL80211_BAND_S1GHZ) {
962 local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
963 goto set_channel;
964 }
965
966 switch (scan_req->scan_width) {
967 case NL80211_BSS_CHAN_WIDTH_5:
968 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
969 break;
970 case NL80211_BSS_CHAN_WIDTH_10:
971 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
972 break;
973 default:
974 case NL80211_BSS_CHAN_WIDTH_20:
975 /* If scanning on oper channel, use whatever channel-type
976 * is currently in use.
977 */
978 oper_scan_width = cfg80211_chandef_to_scan_width(
979 &local->_oper_chandef);
980 if (chan == local->_oper_chandef.chan &&
981 oper_scan_width == scan_req->scan_width)
982 local->scan_chandef = local->_oper_chandef;
983 else
984 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
985 break;
986 case NL80211_BSS_CHAN_WIDTH_1:
987 case NL80211_BSS_CHAN_WIDTH_2:
988 /* shouldn't get here, S1G handled above */
989 WARN_ON(1);
990 break;
991 }
992
993 set_channel:
994 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
995 skip = 1;
996
997 /* advance state machine to next channel/band */
998 local->scan_channel_idx++;
999
1000 if (skip) {
1001 /* if we skip this channel return to the decision state */
1002 local->next_scan_state = SCAN_DECISION;
1003 return;
1004 }
1005
1006 /*
1007 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
1008 * (which unfortunately doesn't say _why_ step a) is done,
1009 * but it waits for the probe delay or until a frame is
1010 * received - and the received frame would update the NAV).
1011 * For now, we do not support waiting until a frame is
1012 * received.
1013 *
1014 * In any case, it is not necessary for a passive scan.
1015 */
1016 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
1017 !scan_req->n_ssids) {
1018 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
1019 local->next_scan_state = SCAN_DECISION;
1020 if (scan_req->n_ssids)
1021 set_bit(SCAN_BEACON_WAIT, &local->scanning);
1022 return;
1023 }
1024
1025 /* active scan, send probes */
1026 *next_delay = IEEE80211_PROBE_DELAY;
1027 local->next_scan_state = SCAN_SEND_PROBE;
1028 }
1029
ieee80211_scan_state_suspend(struct ieee80211_local * local,unsigned long * next_delay)1030 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1031 unsigned long *next_delay)
1032 {
1033 /* switch back to the operating channel */
1034 local->scan_chandef.chan = NULL;
1035 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
1036
1037 /* disable PS */
1038 ieee80211_offchannel_return(local);
1039
1040 *next_delay = HZ / 5;
1041 /* afterwards, resume scan & go to next channel */
1042 local->next_scan_state = SCAN_RESUME;
1043 }
1044
ieee80211_scan_state_resume(struct ieee80211_local * local,unsigned long * next_delay)1045 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1046 unsigned long *next_delay)
1047 {
1048 ieee80211_offchannel_stop_vifs(local);
1049
1050 if (local->ops->flush) {
1051 ieee80211_flush_queues(local, NULL, false);
1052 *next_delay = 0;
1053 } else
1054 *next_delay = HZ / 10;
1055
1056 /* remember when we left the operating channel */
1057 local->leave_oper_channel_time = jiffies;
1058
1059 /* advance to the next channel to be scanned */
1060 local->next_scan_state = SCAN_SET_CHANNEL;
1061 }
1062
ieee80211_scan_work(struct work_struct * work)1063 void ieee80211_scan_work(struct work_struct *work)
1064 {
1065 struct ieee80211_local *local =
1066 container_of(work, struct ieee80211_local, scan_work.work);
1067 struct ieee80211_sub_if_data *sdata;
1068 struct cfg80211_scan_request *scan_req;
1069 unsigned long next_delay = 0;
1070 bool aborted;
1071
1072 mutex_lock(&local->mtx);
1073
1074 if (!ieee80211_can_run_worker(local)) {
1075 aborted = true;
1076 goto out_complete;
1077 }
1078
1079 sdata = rcu_dereference_protected(local->scan_sdata,
1080 lockdep_is_held(&local->mtx));
1081 scan_req = rcu_dereference_protected(local->scan_req,
1082 lockdep_is_held(&local->mtx));
1083
1084 /* When scanning on-channel, the first-callback means completed. */
1085 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1086 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1087 goto out_complete;
1088 }
1089
1090 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1091 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1092 goto out_complete;
1093 }
1094
1095 if (!sdata || !scan_req)
1096 goto out;
1097
1098 if (!local->scanning) {
1099 int rc;
1100
1101 RCU_INIT_POINTER(local->scan_req, NULL);
1102 RCU_INIT_POINTER(local->scan_sdata, NULL);
1103
1104 rc = __ieee80211_start_scan(sdata, scan_req);
1105 if (rc) {
1106 /* need to complete scan in cfg80211 */
1107 rcu_assign_pointer(local->scan_req, scan_req);
1108 aborted = true;
1109 goto out_complete;
1110 } else
1111 goto out;
1112 }
1113
1114 clear_bit(SCAN_BEACON_WAIT, &local->scanning);
1115
1116 /*
1117 * as long as no delay is required advance immediately
1118 * without scheduling a new work
1119 */
1120 do {
1121 if (!ieee80211_sdata_running(sdata)) {
1122 aborted = true;
1123 goto out_complete;
1124 }
1125
1126 if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) &&
1127 local->next_scan_state == SCAN_DECISION)
1128 local->next_scan_state = SCAN_SEND_PROBE;
1129
1130 switch (local->next_scan_state) {
1131 case SCAN_DECISION:
1132 /* if no more bands/channels left, complete scan */
1133 if (local->scan_channel_idx >= scan_req->n_channels) {
1134 aborted = false;
1135 goto out_complete;
1136 }
1137 ieee80211_scan_state_decision(local, &next_delay);
1138 break;
1139 case SCAN_SET_CHANNEL:
1140 ieee80211_scan_state_set_channel(local, &next_delay);
1141 break;
1142 case SCAN_SEND_PROBE:
1143 ieee80211_scan_state_send_probe(local, &next_delay);
1144 break;
1145 case SCAN_SUSPEND:
1146 ieee80211_scan_state_suspend(local, &next_delay);
1147 break;
1148 case SCAN_RESUME:
1149 ieee80211_scan_state_resume(local, &next_delay);
1150 break;
1151 case SCAN_ABORT:
1152 aborted = true;
1153 goto out_complete;
1154 }
1155 } while (next_delay == 0);
1156
1157 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
1158 goto out;
1159
1160 out_complete:
1161 __ieee80211_scan_completed(&local->hw, aborted);
1162 out:
1163 mutex_unlock(&local->mtx);
1164 }
1165
ieee80211_request_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)1166 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1167 struct cfg80211_scan_request *req)
1168 {
1169 int res;
1170
1171 mutex_lock(&sdata->local->mtx);
1172 res = __ieee80211_start_scan(sdata, req);
1173 mutex_unlock(&sdata->local->mtx);
1174
1175 return res;
1176 }
1177
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)1178 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1179 const u8 *ssid, u8 ssid_len,
1180 struct ieee80211_channel **channels,
1181 unsigned int n_channels,
1182 enum nl80211_bss_scan_width scan_width)
1183 {
1184 struct ieee80211_local *local = sdata->local;
1185 int ret = -EBUSY, i, n_ch = 0;
1186 enum nl80211_band band;
1187
1188 mutex_lock(&local->mtx);
1189
1190 /* busy scanning */
1191 if (local->scan_req)
1192 goto unlock;
1193
1194 /* fill internal scan request */
1195 if (!channels) {
1196 int max_n;
1197
1198 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1199 if (!local->hw.wiphy->bands[band] ||
1200 band == NL80211_BAND_6GHZ)
1201 continue;
1202
1203 max_n = local->hw.wiphy->bands[band]->n_channels;
1204 for (i = 0; i < max_n; i++) {
1205 struct ieee80211_channel *tmp_ch =
1206 &local->hw.wiphy->bands[band]->channels[i];
1207
1208 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1209 IEEE80211_CHAN_DISABLED))
1210 continue;
1211
1212 local->int_scan_req->channels[n_ch] = tmp_ch;
1213 n_ch++;
1214 }
1215 }
1216
1217 if (WARN_ON_ONCE(n_ch == 0))
1218 goto unlock;
1219
1220 local->int_scan_req->n_channels = n_ch;
1221 } else {
1222 for (i = 0; i < n_channels; i++) {
1223 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1224 IEEE80211_CHAN_DISABLED))
1225 continue;
1226
1227 local->int_scan_req->channels[n_ch] = channels[i];
1228 n_ch++;
1229 }
1230
1231 if (WARN_ON_ONCE(n_ch == 0))
1232 goto unlock;
1233
1234 local->int_scan_req->n_channels = n_ch;
1235 }
1236
1237 local->int_scan_req->ssids = &local->scan_ssid;
1238 local->int_scan_req->n_ssids = 1;
1239 local->int_scan_req->scan_width = scan_width;
1240 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1241 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1242
1243 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1244 unlock:
1245 mutex_unlock(&local->mtx);
1246 return ret;
1247 }
1248
1249 /*
1250 * Only call this function when a scan can't be queued -- under RTNL.
1251 */
ieee80211_scan_cancel(struct ieee80211_local * local)1252 void ieee80211_scan_cancel(struct ieee80211_local *local)
1253 {
1254 /*
1255 * We are canceling software scan, or deferred scan that was not
1256 * yet really started (see __ieee80211_start_scan ).
1257 *
1258 * Regarding hardware scan:
1259 * - we can not call __ieee80211_scan_completed() as when
1260 * SCAN_HW_SCANNING bit is set this function change
1261 * local->hw_scan_req to operate on 5G band, what race with
1262 * driver which can use local->hw_scan_req
1263 *
1264 * - we can not cancel scan_work since driver can schedule it
1265 * by ieee80211_scan_completed(..., true) to finish scan
1266 *
1267 * Hence we only call the cancel_hw_scan() callback, but the low-level
1268 * driver is still responsible for calling ieee80211_scan_completed()
1269 * after the scan was completed/aborted.
1270 */
1271
1272 mutex_lock(&local->mtx);
1273 if (!local->scan_req)
1274 goto out;
1275
1276 /*
1277 * We have a scan running and the driver already reported completion,
1278 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1279 * cancelled.
1280 */
1281 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1282 test_bit(SCAN_COMPLETED, &local->scanning)) {
1283 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1284 goto out;
1285 }
1286
1287 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1288 /*
1289 * Make sure that __ieee80211_scan_completed doesn't trigger a
1290 * scan on another band.
1291 */
1292 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1293 if (local->ops->cancel_hw_scan)
1294 drv_cancel_hw_scan(local,
1295 rcu_dereference_protected(local->scan_sdata,
1296 lockdep_is_held(&local->mtx)));
1297 goto out;
1298 }
1299
1300 /*
1301 * If the work is currently running, it must be blocked on
1302 * the mutex, but we'll set scan_sdata = NULL and it'll
1303 * simply exit once it acquires the mutex.
1304 */
1305 cancel_delayed_work(&local->scan_work);
1306 /* and clean up */
1307 memset(&local->scan_info, 0, sizeof(local->scan_info));
1308 __ieee80211_scan_completed(&local->hw, true);
1309 out:
1310 mutex_unlock(&local->mtx);
1311 }
1312
__ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1313 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1314 struct cfg80211_sched_scan_request *req)
1315 {
1316 struct ieee80211_local *local = sdata->local;
1317 struct ieee80211_scan_ies sched_scan_ies = {};
1318 struct cfg80211_chan_def chandef;
1319 int ret, i, iebufsz, num_bands = 0;
1320 u32 rate_masks[NUM_NL80211_BANDS] = {};
1321 u8 bands_used = 0;
1322 u8 *ie;
1323 u32 flags = 0;
1324
1325 iebufsz = local->scan_ies_len + req->ie_len;
1326
1327 lockdep_assert_held(&local->mtx);
1328
1329 if (!local->ops->sched_scan_start)
1330 return -ENOTSUPP;
1331
1332 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1333 if (local->hw.wiphy->bands[i]) {
1334 bands_used |= BIT(i);
1335 rate_masks[i] = (u32) -1;
1336 num_bands++;
1337 }
1338 }
1339
1340 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1341 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1342
1343 ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1344 if (!ie) {
1345 ret = -ENOMEM;
1346 goto out;
1347 }
1348
1349 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1350
1351 ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1352 &sched_scan_ies, req->ie,
1353 req->ie_len, bands_used, rate_masks, &chandef,
1354 flags);
1355
1356 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1357 if (ret == 0) {
1358 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1359 rcu_assign_pointer(local->sched_scan_req, req);
1360 }
1361
1362 kfree(ie);
1363
1364 out:
1365 if (ret) {
1366 /* Clean in case of failure after HW restart or upon resume. */
1367 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1368 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1369 }
1370
1371 return ret;
1372 }
1373
ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1374 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1375 struct cfg80211_sched_scan_request *req)
1376 {
1377 struct ieee80211_local *local = sdata->local;
1378 int ret;
1379
1380 mutex_lock(&local->mtx);
1381
1382 if (rcu_access_pointer(local->sched_scan_sdata)) {
1383 mutex_unlock(&local->mtx);
1384 return -EBUSY;
1385 }
1386
1387 ret = __ieee80211_request_sched_scan_start(sdata, req);
1388
1389 mutex_unlock(&local->mtx);
1390 return ret;
1391 }
1392
ieee80211_request_sched_scan_stop(struct ieee80211_local * local)1393 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1394 {
1395 struct ieee80211_sub_if_data *sched_scan_sdata;
1396 int ret = -ENOENT;
1397
1398 mutex_lock(&local->mtx);
1399
1400 if (!local->ops->sched_scan_stop) {
1401 ret = -ENOTSUPP;
1402 goto out;
1403 }
1404
1405 /* We don't want to restart sched scan anymore. */
1406 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1407
1408 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1409 lockdep_is_held(&local->mtx));
1410 if (sched_scan_sdata) {
1411 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1412 if (!ret)
1413 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1414 }
1415 out:
1416 mutex_unlock(&local->mtx);
1417
1418 return ret;
1419 }
1420
ieee80211_sched_scan_results(struct ieee80211_hw * hw)1421 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1422 {
1423 struct ieee80211_local *local = hw_to_local(hw);
1424
1425 trace_api_sched_scan_results(local);
1426
1427 cfg80211_sched_scan_results(hw->wiphy, 0);
1428 }
1429 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1430
ieee80211_sched_scan_end(struct ieee80211_local * local)1431 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1432 {
1433 mutex_lock(&local->mtx);
1434
1435 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1436 mutex_unlock(&local->mtx);
1437 return;
1438 }
1439
1440 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1441
1442 /* If sched scan was aborted by the driver. */
1443 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1444
1445 mutex_unlock(&local->mtx);
1446
1447 cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1448 }
1449
ieee80211_sched_scan_stopped_work(struct work_struct * work)1450 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1451 {
1452 struct ieee80211_local *local =
1453 container_of(work, struct ieee80211_local,
1454 sched_scan_stopped_work);
1455
1456 ieee80211_sched_scan_end(local);
1457 }
1458
ieee80211_sched_scan_stopped(struct ieee80211_hw * hw)1459 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1460 {
1461 struct ieee80211_local *local = hw_to_local(hw);
1462
1463 trace_api_sched_scan_stopped(local);
1464
1465 /*
1466 * this shouldn't really happen, so for simplicity
1467 * simply ignore it, and let mac80211 reconfigure
1468 * the sched scan later on.
1469 */
1470 if (local->in_reconfig)
1471 return;
1472
1473 schedule_work(&local->sched_scan_stopped_work);
1474 }
1475 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
1476