1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Scanning implementation
4 *
5 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
6 * Copyright 2004, Instant802 Networks, Inc.
7 * Copyright 2005, Devicescape Software, Inc.
8 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
9 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
10 * Copyright 2013-2015 Intel Mobile Communications GmbH
11 * Copyright 2016-2017 Intel Deutschland GmbH
12 * Copyright (C) 2018-2020 Intel Corporation
13 */
14
15 #include <linux/if_arp.h>
16 #include <linux/etherdevice.h>
17 #include <linux/rtnetlink.h>
18 #include <net/sch_generic.h>
19 #include <linux/slab.h>
20 #include <linux/export.h>
21 #include <linux/random.h>
22 #include <net/mac80211.h>
23
24 #include "ieee80211_i.h"
25 #include "driver-ops.h"
26 #include "mesh.h"
27
28 #define IEEE80211_PROBE_DELAY (HZ / 33)
29 #define IEEE80211_CHANNEL_TIME (HZ / 33)
30 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
31
ieee80211_rx_bss_put(struct ieee80211_local * local,struct ieee80211_bss * bss)32 void ieee80211_rx_bss_put(struct ieee80211_local *local,
33 struct ieee80211_bss *bss)
34 {
35 if (!bss)
36 return;
37 cfg80211_put_bss(local->hw.wiphy,
38 container_of((void *)bss, struct cfg80211_bss, priv));
39 }
40
is_uapsd_supported(struct ieee802_11_elems * elems)41 static bool is_uapsd_supported(struct ieee802_11_elems *elems)
42 {
43 u8 qos_info;
44
45 if (elems->wmm_info && elems->wmm_info_len == 7
46 && elems->wmm_info[5] == 1)
47 qos_info = elems->wmm_info[6];
48 else if (elems->wmm_param && elems->wmm_param_len == 24
49 && elems->wmm_param[5] == 1)
50 qos_info = elems->wmm_param[6];
51 else
52 /* no valid wmm information or parameter element found */
53 return false;
54
55 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
56 }
57
58 static void
ieee80211_update_bss_from_elems(struct ieee80211_local * local,struct ieee80211_bss * bss,struct ieee802_11_elems * elems,struct ieee80211_rx_status * rx_status,bool beacon)59 ieee80211_update_bss_from_elems(struct ieee80211_local *local,
60 struct ieee80211_bss *bss,
61 struct ieee802_11_elems *elems,
62 struct ieee80211_rx_status *rx_status,
63 bool beacon)
64 {
65 int clen, srlen;
66
67 if (beacon)
68 bss->device_ts_beacon = rx_status->device_timestamp;
69 else
70 bss->device_ts_presp = rx_status->device_timestamp;
71
72 if (elems->parse_error) {
73 if (beacon)
74 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
75 else
76 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
77 } else {
78 if (beacon)
79 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
80 else
81 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
82 }
83
84 /* save the ERP value so that it is available at association time */
85 if (elems->erp_info && (!elems->parse_error ||
86 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
87 bss->erp_value = elems->erp_info[0];
88 bss->has_erp_value = true;
89 if (!elems->parse_error)
90 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
91 }
92
93 /* replace old supported rates if we get new values */
94 if (!elems->parse_error ||
95 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
96 srlen = 0;
97 if (elems->supp_rates) {
98 clen = IEEE80211_MAX_SUPP_RATES;
99 if (clen > elems->supp_rates_len)
100 clen = elems->supp_rates_len;
101 memcpy(bss->supp_rates, elems->supp_rates, clen);
102 srlen += clen;
103 }
104 if (elems->ext_supp_rates) {
105 clen = IEEE80211_MAX_SUPP_RATES - srlen;
106 if (clen > elems->ext_supp_rates_len)
107 clen = elems->ext_supp_rates_len;
108 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
109 clen);
110 srlen += clen;
111 }
112 if (srlen) {
113 bss->supp_rates_len = srlen;
114 if (!elems->parse_error)
115 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
116 }
117 }
118
119 if (!elems->parse_error ||
120 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
121 bss->wmm_used = elems->wmm_param || elems->wmm_info;
122 bss->uapsd_supported = is_uapsd_supported(elems);
123 if (!elems->parse_error)
124 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
125 }
126
127 if (beacon) {
128 struct ieee80211_supported_band *sband =
129 local->hw.wiphy->bands[rx_status->band];
130 if (!(rx_status->encoding == RX_ENC_HT) &&
131 !(rx_status->encoding == RX_ENC_VHT))
132 bss->beacon_rate =
133 &sband->bitrates[rx_status->rate_idx];
134 }
135
136 if (elems->vht_cap_elem)
137 bss->vht_cap_info =
138 le32_to_cpu(elems->vht_cap_elem->vht_cap_info);
139 else
140 bss->vht_cap_info = 0;
141 }
142
143 struct ieee80211_bss *
ieee80211_bss_info_update(struct ieee80211_local * local,struct ieee80211_rx_status * rx_status,struct ieee80211_mgmt * mgmt,size_t len,struct ieee80211_channel * channel)144 ieee80211_bss_info_update(struct ieee80211_local *local,
145 struct ieee80211_rx_status *rx_status,
146 struct ieee80211_mgmt *mgmt, size_t len,
147 struct ieee80211_channel *channel)
148 {
149 bool beacon = ieee80211_is_beacon(mgmt->frame_control) ||
150 ieee80211_is_s1g_beacon(mgmt->frame_control);
151 struct cfg80211_bss *cbss, *non_tx_cbss;
152 struct ieee80211_bss *bss, *non_tx_bss;
153 struct cfg80211_inform_bss bss_meta = {
154 .boottime_ns = rx_status->boottime_ns,
155 };
156 bool signal_valid;
157 struct ieee80211_sub_if_data *scan_sdata;
158 struct ieee802_11_elems elems;
159 size_t baselen;
160 u8 *elements;
161
162 if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
163 bss_meta.signal = 0; /* invalid signal indication */
164 else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
165 bss_meta.signal = rx_status->signal * 100;
166 else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
167 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
168
169 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
170 if (rx_status->bw == RATE_INFO_BW_5)
171 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
172 else if (rx_status->bw == RATE_INFO_BW_10)
173 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
174
175 bss_meta.chan = channel;
176
177 rcu_read_lock();
178 scan_sdata = rcu_dereference(local->scan_sdata);
179 if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
180 scan_sdata->vif.bss_conf.assoc &&
181 ieee80211_have_rx_timestamp(rx_status)) {
182 bss_meta.parent_tsf =
183 ieee80211_calculate_rx_timestamp(local, rx_status,
184 len + FCS_LEN, 24);
185 ether_addr_copy(bss_meta.parent_bssid,
186 scan_sdata->vif.bss_conf.bssid);
187 }
188 rcu_read_unlock();
189
190 cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
191 mgmt, len, GFP_ATOMIC);
192 if (!cbss)
193 return NULL;
194
195 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
196 elements = mgmt->u.probe_resp.variable;
197 baselen = offsetof(struct ieee80211_mgmt,
198 u.probe_resp.variable);
199 } else if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
200 struct ieee80211_ext *ext = (void *) mgmt;
201
202 baselen = offsetof(struct ieee80211_ext, u.s1g_beacon.variable);
203 elements = ext->u.s1g_beacon.variable;
204 } else {
205 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
206 elements = mgmt->u.beacon.variable;
207 }
208
209 if (baselen > len)
210 return NULL;
211
212 ieee802_11_parse_elems(elements, len - baselen, false, &elems,
213 mgmt->bssid, cbss->bssid);
214
215 /* In case the signal is invalid update the status */
216 signal_valid = channel == cbss->channel;
217 if (!signal_valid)
218 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
219
220 bss = (void *)cbss->priv;
221 ieee80211_update_bss_from_elems(local, bss, &elems, rx_status, beacon);
222
223 list_for_each_entry(non_tx_cbss, &cbss->nontrans_list, nontrans_list) {
224 non_tx_bss = (void *)non_tx_cbss->priv;
225
226 ieee80211_update_bss_from_elems(local, non_tx_bss, &elems,
227 rx_status, beacon);
228 }
229
230 kfree(elems.nontx_profile);
231
232 return bss;
233 }
234
ieee80211_scan_accept_presp(struct ieee80211_sub_if_data * sdata,u32 scan_flags,const u8 * da)235 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
236 u32 scan_flags, const u8 *da)
237 {
238 if (!sdata)
239 return false;
240 /* accept broadcast for OCE */
241 if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
242 is_broadcast_ether_addr(da))
243 return true;
244 if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
245 return true;
246 return ether_addr_equal(da, sdata->vif.addr);
247 }
248
ieee80211_scan_rx(struct ieee80211_local * local,struct sk_buff * skb)249 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
250 {
251 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
252 struct ieee80211_sub_if_data *sdata1, *sdata2;
253 struct ieee80211_mgmt *mgmt = (void *)skb->data;
254 struct ieee80211_bss *bss;
255 struct ieee80211_channel *channel;
256 size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
257 u.probe_resp.variable);
258
259 if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
260 !ieee80211_is_beacon(mgmt->frame_control) &&
261 !ieee80211_is_s1g_beacon(mgmt->frame_control))
262 return;
263
264 if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
265 if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
266 min_hdr_len = offsetof(struct ieee80211_ext,
267 u.s1g_short_beacon.variable);
268 else
269 min_hdr_len = offsetof(struct ieee80211_ext,
270 u.s1g_beacon);
271 }
272
273 if (skb->len < min_hdr_len)
274 return;
275
276 sdata1 = rcu_dereference(local->scan_sdata);
277 sdata2 = rcu_dereference(local->sched_scan_sdata);
278
279 if (likely(!sdata1 && !sdata2))
280 return;
281
282 if (test_and_clear_bit(SCAN_BEACON_WAIT, &local->scanning)) {
283 /*
284 * we were passive scanning because of radar/no-IR, but
285 * the beacon/proberesp rx gives us an opportunity to upgrade
286 * to active scan
287 */
288 set_bit(SCAN_BEACON_DONE, &local->scanning);
289 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
290 }
291
292 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
293 struct cfg80211_scan_request *scan_req;
294 struct cfg80211_sched_scan_request *sched_scan_req;
295 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
296
297 scan_req = rcu_dereference(local->scan_req);
298 sched_scan_req = rcu_dereference(local->sched_scan_req);
299
300 if (scan_req)
301 scan_req_flags = scan_req->flags;
302
303 if (sched_scan_req)
304 sched_scan_req_flags = sched_scan_req->flags;
305
306 /* ignore ProbeResp to foreign address or non-bcast (OCE)
307 * unless scanning with randomised address
308 */
309 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
310 mgmt->da) &&
311 !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
312 mgmt->da))
313 return;
314 }
315
316 channel = ieee80211_get_channel_khz(local->hw.wiphy,
317 ieee80211_rx_status_to_khz(rx_status));
318
319 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
320 return;
321
322 bss = ieee80211_bss_info_update(local, rx_status,
323 mgmt, skb->len,
324 channel);
325 if (bss)
326 ieee80211_rx_bss_put(local, bss);
327 }
328
329 static void
ieee80211_prepare_scan_chandef(struct cfg80211_chan_def * chandef,enum nl80211_bss_scan_width scan_width)330 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
331 enum nl80211_bss_scan_width scan_width)
332 {
333 memset(chandef, 0, sizeof(*chandef));
334 switch (scan_width) {
335 case NL80211_BSS_CHAN_WIDTH_5:
336 chandef->width = NL80211_CHAN_WIDTH_5;
337 break;
338 case NL80211_BSS_CHAN_WIDTH_10:
339 chandef->width = NL80211_CHAN_WIDTH_10;
340 break;
341 default:
342 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
343 break;
344 }
345 }
346
347 /* return false if no more work */
ieee80211_prep_hw_scan(struct ieee80211_sub_if_data * sdata)348 static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
349 {
350 struct ieee80211_local *local = sdata->local;
351 struct cfg80211_scan_request *req;
352 struct cfg80211_chan_def chandef;
353 u8 bands_used = 0;
354 int i, ielen, n_chans;
355 u32 flags = 0;
356
357 req = rcu_dereference_protected(local->scan_req,
358 lockdep_is_held(&local->mtx));
359
360 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
361 return false;
362
363 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
364 for (i = 0; i < req->n_channels; i++) {
365 local->hw_scan_req->req.channels[i] = req->channels[i];
366 bands_used |= BIT(req->channels[i]->band);
367 }
368
369 n_chans = req->n_channels;
370 } else {
371 do {
372 if (local->hw_scan_band == NUM_NL80211_BANDS)
373 return false;
374
375 n_chans = 0;
376
377 for (i = 0; i < req->n_channels; i++) {
378 if (req->channels[i]->band !=
379 local->hw_scan_band)
380 continue;
381 local->hw_scan_req->req.channels[n_chans] =
382 req->channels[i];
383 n_chans++;
384 bands_used |= BIT(req->channels[i]->band);
385 }
386
387 local->hw_scan_band++;
388 } while (!n_chans);
389 }
390
391 local->hw_scan_req->req.n_channels = n_chans;
392 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
393
394 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
395 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
396
397 ielen = ieee80211_build_preq_ies(sdata,
398 (u8 *)local->hw_scan_req->req.ie,
399 local->hw_scan_ies_bufsize,
400 &local->hw_scan_req->ies,
401 req->ie, req->ie_len,
402 bands_used, req->rates, &chandef,
403 flags);
404 local->hw_scan_req->req.ie_len = ielen;
405 local->hw_scan_req->req.no_cck = req->no_cck;
406 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
407 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
408 req->mac_addr_mask);
409 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
410
411 return true;
412 }
413
__ieee80211_scan_completed(struct ieee80211_hw * hw,bool aborted)414 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
415 {
416 struct ieee80211_local *local = hw_to_local(hw);
417 bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
418 bool was_scanning = local->scanning;
419 struct cfg80211_scan_request *scan_req;
420 struct ieee80211_sub_if_data *scan_sdata;
421 struct ieee80211_sub_if_data *sdata;
422
423 lockdep_assert_held(&local->mtx);
424
425 /*
426 * It's ok to abort a not-yet-running scan (that
427 * we have one at all will be verified by checking
428 * local->scan_req next), but not to complete it
429 * successfully.
430 */
431 if (WARN_ON(!local->scanning && !aborted))
432 aborted = true;
433
434 if (WARN_ON(!local->scan_req))
435 return;
436
437 scan_sdata = rcu_dereference_protected(local->scan_sdata,
438 lockdep_is_held(&local->mtx));
439
440 if (hw_scan && !aborted &&
441 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
442 ieee80211_prep_hw_scan(scan_sdata)) {
443 int rc;
444
445 rc = drv_hw_scan(local,
446 rcu_dereference_protected(local->scan_sdata,
447 lockdep_is_held(&local->mtx)),
448 local->hw_scan_req);
449
450 if (rc == 0)
451 return;
452
453 /* HW scan failed and is going to be reported as aborted,
454 * so clear old scan info.
455 */
456 memset(&local->scan_info, 0, sizeof(local->scan_info));
457 aborted = true;
458 }
459
460 kfree(local->hw_scan_req);
461 local->hw_scan_req = NULL;
462
463 scan_req = rcu_dereference_protected(local->scan_req,
464 lockdep_is_held(&local->mtx));
465
466 RCU_INIT_POINTER(local->scan_req, NULL);
467 RCU_INIT_POINTER(local->scan_sdata, NULL);
468
469 local->scanning = 0;
470 local->scan_chandef.chan = NULL;
471
472 synchronize_rcu();
473
474 if (scan_req != local->int_scan_req) {
475 local->scan_info.aborted = aborted;
476 cfg80211_scan_done(scan_req, &local->scan_info);
477 }
478
479 /* Set power back to normal operating levels. */
480 ieee80211_hw_config(local, 0);
481
482 if (!hw_scan) {
483 ieee80211_configure_filter(local);
484 drv_sw_scan_complete(local, scan_sdata);
485 ieee80211_offchannel_return(local);
486 }
487
488 ieee80211_recalc_idle(local);
489
490 ieee80211_mlme_notify_scan_completed(local);
491 ieee80211_ibss_notify_scan_completed(local);
492
493 /* Requeue all the work that might have been ignored while
494 * the scan was in progress; if there was none this will
495 * just be a no-op for the particular interface.
496 */
497 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
498 if (ieee80211_sdata_running(sdata))
499 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
500 }
501
502 if (was_scanning)
503 ieee80211_start_next_roc(local);
504 }
505
ieee80211_scan_completed(struct ieee80211_hw * hw,struct cfg80211_scan_info * info)506 void ieee80211_scan_completed(struct ieee80211_hw *hw,
507 struct cfg80211_scan_info *info)
508 {
509 struct ieee80211_local *local = hw_to_local(hw);
510
511 trace_api_scan_completed(local, info->aborted);
512
513 set_bit(SCAN_COMPLETED, &local->scanning);
514 if (info->aborted)
515 set_bit(SCAN_ABORTED, &local->scanning);
516
517 memcpy(&local->scan_info, info, sizeof(*info));
518
519 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
520 }
521 EXPORT_SYMBOL(ieee80211_scan_completed);
522
ieee80211_start_sw_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)523 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
524 struct ieee80211_sub_if_data *sdata)
525 {
526 /* Software scan is not supported in multi-channel cases */
527 if (local->use_chanctx)
528 return -EOPNOTSUPP;
529
530 /*
531 * Hardware/driver doesn't support hw_scan, so use software
532 * scanning instead. First send a nullfunc frame with power save
533 * bit on so that AP will buffer the frames for us while we are not
534 * listening, then send probe requests to each channel and wait for
535 * the responses. After all channels are scanned, tune back to the
536 * original channel and send a nullfunc frame with power save bit
537 * off to trigger the AP to send us all the buffered frames.
538 *
539 * Note that while local->sw_scanning is true everything else but
540 * nullfunc frames and probe requests will be dropped in
541 * ieee80211_tx_h_check_assoc().
542 */
543 drv_sw_scan_start(local, sdata, local->scan_addr);
544
545 local->leave_oper_channel_time = jiffies;
546 local->next_scan_state = SCAN_DECISION;
547 local->scan_channel_idx = 0;
548
549 ieee80211_offchannel_stop_vifs(local);
550
551 /* ensure nullfunc is transmitted before leaving operating channel */
552 ieee80211_flush_queues(local, NULL, false);
553
554 ieee80211_configure_filter(local);
555
556 /* We need to set power level at maximum rate for scanning. */
557 ieee80211_hw_config(local, 0);
558
559 ieee80211_queue_delayed_work(&local->hw,
560 &local->scan_work, 0);
561
562 return 0;
563 }
564
__ieee80211_can_leave_ch(struct ieee80211_sub_if_data * sdata)565 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
566 {
567 struct ieee80211_local *local = sdata->local;
568 struct ieee80211_sub_if_data *sdata_iter;
569
570 if (!ieee80211_is_radar_required(local))
571 return true;
572
573 if (!regulatory_pre_cac_allowed(local->hw.wiphy))
574 return false;
575
576 mutex_lock(&local->iflist_mtx);
577 list_for_each_entry(sdata_iter, &local->interfaces, list) {
578 if (sdata_iter->wdev.cac_started) {
579 mutex_unlock(&local->iflist_mtx);
580 return false;
581 }
582 }
583 mutex_unlock(&local->iflist_mtx);
584
585 return true;
586 }
587
ieee80211_can_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)588 static bool ieee80211_can_scan(struct ieee80211_local *local,
589 struct ieee80211_sub_if_data *sdata)
590 {
591 if (!__ieee80211_can_leave_ch(sdata))
592 return false;
593
594 if (!list_empty(&local->roc_list))
595 return false;
596
597 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
598 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
599 return false;
600
601 return true;
602 }
603
ieee80211_run_deferred_scan(struct ieee80211_local * local)604 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
605 {
606 lockdep_assert_held(&local->mtx);
607
608 if (!local->scan_req || local->scanning)
609 return;
610
611 if (!ieee80211_can_scan(local,
612 rcu_dereference_protected(
613 local->scan_sdata,
614 lockdep_is_held(&local->mtx))))
615 return;
616
617 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
618 round_jiffies_relative(0));
619 }
620
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)621 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
622 const u8 *src, const u8 *dst,
623 const u8 *ssid, size_t ssid_len,
624 const u8 *ie, size_t ie_len,
625 u32 ratemask, u32 flags, u32 tx_flags,
626 struct ieee80211_channel *channel)
627 {
628 struct sk_buff *skb;
629
630 skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
631 ssid, ssid_len,
632 ie, ie_len, flags);
633
634 if (skb) {
635 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
636 struct ieee80211_hdr *hdr = (void *)skb->data;
637 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
638 u16 sn = get_random_u32();
639
640 info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
641 hdr->seq_ctrl =
642 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
643 }
644 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
645 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
646 }
647 }
648
ieee80211_scan_state_send_probe(struct ieee80211_local * local,unsigned long * next_delay)649 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
650 unsigned long *next_delay)
651 {
652 int i;
653 struct ieee80211_sub_if_data *sdata;
654 struct cfg80211_scan_request *scan_req;
655 enum nl80211_band band = local->hw.conf.chandef.chan->band;
656 u32 flags = 0, tx_flags;
657
658 scan_req = rcu_dereference_protected(local->scan_req,
659 lockdep_is_held(&local->mtx));
660
661 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
662 if (scan_req->no_cck)
663 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
664 if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
665 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
666 if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
667 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
668
669 sdata = rcu_dereference_protected(local->scan_sdata,
670 lockdep_is_held(&local->mtx));
671
672 for (i = 0; i < scan_req->n_ssids; i++)
673 ieee80211_send_scan_probe_req(
674 sdata, local->scan_addr, scan_req->bssid,
675 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
676 scan_req->ie, scan_req->ie_len,
677 scan_req->rates[band], flags,
678 tx_flags, local->hw.conf.chandef.chan);
679
680 /*
681 * After sending probe requests, wait for probe responses
682 * on the channel.
683 */
684 *next_delay = IEEE80211_CHANNEL_TIME;
685 local->next_scan_state = SCAN_DECISION;
686 }
687
__ieee80211_start_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)688 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
689 struct cfg80211_scan_request *req)
690 {
691 struct ieee80211_local *local = sdata->local;
692 bool hw_scan = local->ops->hw_scan;
693 int rc;
694
695 lockdep_assert_held(&local->mtx);
696
697 if (local->scan_req)
698 return -EBUSY;
699
700 if (!__ieee80211_can_leave_ch(sdata))
701 return -EBUSY;
702
703 if (!ieee80211_can_scan(local, sdata)) {
704 /* wait for the work to finish/time out */
705 rcu_assign_pointer(local->scan_req, req);
706 rcu_assign_pointer(local->scan_sdata, sdata);
707 return 0;
708 }
709
710 again:
711 if (hw_scan) {
712 u8 *ies;
713
714 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
715
716 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
717 int i, n_bands = 0;
718 u8 bands_counted = 0;
719
720 for (i = 0; i < req->n_channels; i++) {
721 if (bands_counted & BIT(req->channels[i]->band))
722 continue;
723 bands_counted |= BIT(req->channels[i]->band);
724 n_bands++;
725 }
726
727 local->hw_scan_ies_bufsize *= n_bands;
728 }
729
730 local->hw_scan_req = kmalloc(
731 sizeof(*local->hw_scan_req) +
732 req->n_channels * sizeof(req->channels[0]) +
733 local->hw_scan_ies_bufsize, GFP_KERNEL);
734 if (!local->hw_scan_req)
735 return -ENOMEM;
736
737 local->hw_scan_req->req.ssids = req->ssids;
738 local->hw_scan_req->req.n_ssids = req->n_ssids;
739 ies = (u8 *)local->hw_scan_req +
740 sizeof(*local->hw_scan_req) +
741 req->n_channels * sizeof(req->channels[0]);
742 local->hw_scan_req->req.ie = ies;
743 local->hw_scan_req->req.flags = req->flags;
744 eth_broadcast_addr(local->hw_scan_req->req.bssid);
745 local->hw_scan_req->req.duration = req->duration;
746 local->hw_scan_req->req.duration_mandatory =
747 req->duration_mandatory;
748
749 local->hw_scan_band = 0;
750 local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
751 local->hw_scan_req->req.scan_6ghz_params =
752 req->scan_6ghz_params;
753 local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
754
755 /*
756 * After allocating local->hw_scan_req, we must
757 * go through until ieee80211_prep_hw_scan(), so
758 * anything that might be changed here and leave
759 * this function early must not go after this
760 * allocation.
761 */
762 }
763
764 rcu_assign_pointer(local->scan_req, req);
765 rcu_assign_pointer(local->scan_sdata, sdata);
766
767 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
768 get_random_mask_addr(local->scan_addr,
769 req->mac_addr,
770 req->mac_addr_mask);
771 else
772 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
773
774 if (hw_scan) {
775 __set_bit(SCAN_HW_SCANNING, &local->scanning);
776 } else if ((req->n_channels == 1) &&
777 (req->channels[0] == local->_oper_chandef.chan)) {
778 /*
779 * If we are scanning only on the operating channel
780 * then we do not need to stop normal activities
781 */
782 unsigned long next_delay;
783
784 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
785
786 ieee80211_recalc_idle(local);
787
788 /* Notify driver scan is starting, keep order of operations
789 * same as normal software scan, in case that matters. */
790 drv_sw_scan_start(local, sdata, local->scan_addr);
791
792 ieee80211_configure_filter(local); /* accept probe-responses */
793
794 /* We need to ensure power level is at max for scanning. */
795 ieee80211_hw_config(local, 0);
796
797 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
798 IEEE80211_CHAN_RADAR)) ||
799 !req->n_ssids) {
800 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
801 if (req->n_ssids)
802 set_bit(SCAN_BEACON_WAIT, &local->scanning);
803 } else {
804 ieee80211_scan_state_send_probe(local, &next_delay);
805 next_delay = IEEE80211_CHANNEL_TIME;
806 }
807
808 /* Now, just wait a bit and we are all done! */
809 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
810 next_delay);
811 return 0;
812 } else {
813 /* Do normal software scan */
814 __set_bit(SCAN_SW_SCANNING, &local->scanning);
815 }
816
817 ieee80211_recalc_idle(local);
818
819 if (hw_scan) {
820 WARN_ON(!ieee80211_prep_hw_scan(sdata));
821 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
822 } else {
823 rc = ieee80211_start_sw_scan(local, sdata);
824 }
825
826 if (rc) {
827 kfree(local->hw_scan_req);
828 local->hw_scan_req = NULL;
829 local->scanning = 0;
830
831 ieee80211_recalc_idle(local);
832
833 local->scan_req = NULL;
834 RCU_INIT_POINTER(local->scan_sdata, NULL);
835 }
836
837 if (hw_scan && rc == 1) {
838 /*
839 * we can't fall back to software for P2P-GO
840 * as it must update NoA etc.
841 */
842 if (ieee80211_vif_type_p2p(&sdata->vif) ==
843 NL80211_IFTYPE_P2P_GO)
844 return -EOPNOTSUPP;
845 hw_scan = false;
846 goto again;
847 }
848
849 return rc;
850 }
851
852 static unsigned long
ieee80211_scan_get_channel_time(struct ieee80211_channel * chan)853 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
854 {
855 /*
856 * TODO: channel switching also consumes quite some time,
857 * add that delay as well to get a better estimation
858 */
859 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
860 return IEEE80211_PASSIVE_CHANNEL_TIME;
861 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
862 }
863
ieee80211_scan_state_decision(struct ieee80211_local * local,unsigned long * next_delay)864 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
865 unsigned long *next_delay)
866 {
867 bool associated = false;
868 bool tx_empty = true;
869 bool bad_latency;
870 struct ieee80211_sub_if_data *sdata;
871 struct ieee80211_channel *next_chan;
872 enum mac80211_scan_state next_scan_state;
873 struct cfg80211_scan_request *scan_req;
874
875 /*
876 * check if at least one STA interface is associated,
877 * check if at least one STA interface has pending tx frames
878 * and grab the lowest used beacon interval
879 */
880 mutex_lock(&local->iflist_mtx);
881 list_for_each_entry(sdata, &local->interfaces, list) {
882 if (!ieee80211_sdata_running(sdata))
883 continue;
884
885 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
886 if (sdata->u.mgd.associated) {
887 associated = true;
888
889 if (!qdisc_all_tx_empty(sdata->dev)) {
890 tx_empty = false;
891 break;
892 }
893 }
894 }
895 }
896 mutex_unlock(&local->iflist_mtx);
897
898 scan_req = rcu_dereference_protected(local->scan_req,
899 lockdep_is_held(&local->mtx));
900
901 next_chan = scan_req->channels[local->scan_channel_idx];
902
903 /*
904 * we're currently scanning a different channel, let's
905 * see if we can scan another channel without interfering
906 * with the current traffic situation.
907 *
908 * Keep good latency, do not stay off-channel more than 125 ms.
909 */
910
911 bad_latency = time_after(jiffies +
912 ieee80211_scan_get_channel_time(next_chan),
913 local->leave_oper_channel_time + HZ / 8);
914
915 if (associated && !tx_empty) {
916 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
917 next_scan_state = SCAN_ABORT;
918 else
919 next_scan_state = SCAN_SUSPEND;
920 } else if (associated && bad_latency) {
921 next_scan_state = SCAN_SUSPEND;
922 } else {
923 next_scan_state = SCAN_SET_CHANNEL;
924 }
925
926 local->next_scan_state = next_scan_state;
927
928 *next_delay = 0;
929 }
930
ieee80211_scan_state_set_channel(struct ieee80211_local * local,unsigned long * next_delay)931 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
932 unsigned long *next_delay)
933 {
934 int skip;
935 struct ieee80211_channel *chan;
936 enum nl80211_bss_scan_width oper_scan_width;
937 struct cfg80211_scan_request *scan_req;
938
939 scan_req = rcu_dereference_protected(local->scan_req,
940 lockdep_is_held(&local->mtx));
941
942 skip = 0;
943 chan = scan_req->channels[local->scan_channel_idx];
944
945 local->scan_chandef.chan = chan;
946 local->scan_chandef.center_freq1 = chan->center_freq;
947 local->scan_chandef.freq1_offset = chan->freq_offset;
948 local->scan_chandef.center_freq2 = 0;
949
950 /* For scanning on the S1G band, ignore scan_width (which is constant
951 * across all channels) for now since channel width is specific to each
952 * channel. Detect the required channel width here and likely revisit
953 * later. Maybe scan_width could be used to build the channel scan list?
954 */
955 if (chan->band == NL80211_BAND_S1GHZ) {
956 local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
957 goto set_channel;
958 }
959
960 switch (scan_req->scan_width) {
961 case NL80211_BSS_CHAN_WIDTH_5:
962 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
963 break;
964 case NL80211_BSS_CHAN_WIDTH_10:
965 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
966 break;
967 default:
968 case NL80211_BSS_CHAN_WIDTH_20:
969 /* If scanning on oper channel, use whatever channel-type
970 * is currently in use.
971 */
972 oper_scan_width = cfg80211_chandef_to_scan_width(
973 &local->_oper_chandef);
974 if (chan == local->_oper_chandef.chan &&
975 oper_scan_width == scan_req->scan_width)
976 local->scan_chandef = local->_oper_chandef;
977 else
978 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
979 break;
980 case NL80211_BSS_CHAN_WIDTH_1:
981 case NL80211_BSS_CHAN_WIDTH_2:
982 /* shouldn't get here, S1G handled above */
983 WARN_ON(1);
984 break;
985 }
986
987 set_channel:
988 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
989 skip = 1;
990
991 /* advance state machine to next channel/band */
992 local->scan_channel_idx++;
993
994 if (skip) {
995 /* if we skip this channel return to the decision state */
996 local->next_scan_state = SCAN_DECISION;
997 return;
998 }
999
1000 /*
1001 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
1002 * (which unfortunately doesn't say _why_ step a) is done,
1003 * but it waits for the probe delay or until a frame is
1004 * received - and the received frame would update the NAV).
1005 * For now, we do not support waiting until a frame is
1006 * received.
1007 *
1008 * In any case, it is not necessary for a passive scan.
1009 */
1010 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
1011 !scan_req->n_ssids) {
1012 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
1013 local->next_scan_state = SCAN_DECISION;
1014 if (scan_req->n_ssids)
1015 set_bit(SCAN_BEACON_WAIT, &local->scanning);
1016 return;
1017 }
1018
1019 /* active scan, send probes */
1020 *next_delay = IEEE80211_PROBE_DELAY;
1021 local->next_scan_state = SCAN_SEND_PROBE;
1022 }
1023
ieee80211_scan_state_suspend(struct ieee80211_local * local,unsigned long * next_delay)1024 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1025 unsigned long *next_delay)
1026 {
1027 /* switch back to the operating channel */
1028 local->scan_chandef.chan = NULL;
1029 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
1030
1031 /* disable PS */
1032 ieee80211_offchannel_return(local);
1033
1034 *next_delay = HZ / 5;
1035 /* afterwards, resume scan & go to next channel */
1036 local->next_scan_state = SCAN_RESUME;
1037 }
1038
ieee80211_scan_state_resume(struct ieee80211_local * local,unsigned long * next_delay)1039 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1040 unsigned long *next_delay)
1041 {
1042 ieee80211_offchannel_stop_vifs(local);
1043
1044 if (local->ops->flush) {
1045 ieee80211_flush_queues(local, NULL, false);
1046 *next_delay = 0;
1047 } else
1048 *next_delay = HZ / 10;
1049
1050 /* remember when we left the operating channel */
1051 local->leave_oper_channel_time = jiffies;
1052
1053 /* advance to the next channel to be scanned */
1054 local->next_scan_state = SCAN_SET_CHANNEL;
1055 }
1056
ieee80211_scan_work(struct work_struct * work)1057 void ieee80211_scan_work(struct work_struct *work)
1058 {
1059 struct ieee80211_local *local =
1060 container_of(work, struct ieee80211_local, scan_work.work);
1061 struct ieee80211_sub_if_data *sdata;
1062 struct cfg80211_scan_request *scan_req;
1063 unsigned long next_delay = 0;
1064 bool aborted;
1065
1066 mutex_lock(&local->mtx);
1067
1068 if (!ieee80211_can_run_worker(local)) {
1069 aborted = true;
1070 goto out_complete;
1071 }
1072
1073 sdata = rcu_dereference_protected(local->scan_sdata,
1074 lockdep_is_held(&local->mtx));
1075 scan_req = rcu_dereference_protected(local->scan_req,
1076 lockdep_is_held(&local->mtx));
1077
1078 /* When scanning on-channel, the first-callback means completed. */
1079 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1080 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1081 goto out_complete;
1082 }
1083
1084 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1085 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1086 goto out_complete;
1087 }
1088
1089 if (!sdata || !scan_req)
1090 goto out;
1091
1092 if (!local->scanning) {
1093 int rc;
1094
1095 RCU_INIT_POINTER(local->scan_req, NULL);
1096 RCU_INIT_POINTER(local->scan_sdata, NULL);
1097
1098 rc = __ieee80211_start_scan(sdata, scan_req);
1099 if (rc) {
1100 /* need to complete scan in cfg80211 */
1101 rcu_assign_pointer(local->scan_req, scan_req);
1102 aborted = true;
1103 goto out_complete;
1104 } else
1105 goto out;
1106 }
1107
1108 clear_bit(SCAN_BEACON_WAIT, &local->scanning);
1109
1110 /*
1111 * as long as no delay is required advance immediately
1112 * without scheduling a new work
1113 */
1114 do {
1115 if (!ieee80211_sdata_running(sdata)) {
1116 aborted = true;
1117 goto out_complete;
1118 }
1119
1120 if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) &&
1121 local->next_scan_state == SCAN_DECISION)
1122 local->next_scan_state = SCAN_SEND_PROBE;
1123
1124 switch (local->next_scan_state) {
1125 case SCAN_DECISION:
1126 /* if no more bands/channels left, complete scan */
1127 if (local->scan_channel_idx >= scan_req->n_channels) {
1128 aborted = false;
1129 goto out_complete;
1130 }
1131 ieee80211_scan_state_decision(local, &next_delay);
1132 break;
1133 case SCAN_SET_CHANNEL:
1134 ieee80211_scan_state_set_channel(local, &next_delay);
1135 break;
1136 case SCAN_SEND_PROBE:
1137 ieee80211_scan_state_send_probe(local, &next_delay);
1138 break;
1139 case SCAN_SUSPEND:
1140 ieee80211_scan_state_suspend(local, &next_delay);
1141 break;
1142 case SCAN_RESUME:
1143 ieee80211_scan_state_resume(local, &next_delay);
1144 break;
1145 case SCAN_ABORT:
1146 aborted = true;
1147 goto out_complete;
1148 }
1149 } while (next_delay == 0);
1150
1151 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
1152 goto out;
1153
1154 out_complete:
1155 __ieee80211_scan_completed(&local->hw, aborted);
1156 out:
1157 mutex_unlock(&local->mtx);
1158 }
1159
ieee80211_request_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)1160 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1161 struct cfg80211_scan_request *req)
1162 {
1163 int res;
1164
1165 mutex_lock(&sdata->local->mtx);
1166 res = __ieee80211_start_scan(sdata, req);
1167 mutex_unlock(&sdata->local->mtx);
1168
1169 return res;
1170 }
1171
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)1172 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1173 const u8 *ssid, u8 ssid_len,
1174 struct ieee80211_channel **channels,
1175 unsigned int n_channels,
1176 enum nl80211_bss_scan_width scan_width)
1177 {
1178 struct ieee80211_local *local = sdata->local;
1179 int ret = -EBUSY, i, n_ch = 0;
1180 enum nl80211_band band;
1181
1182 mutex_lock(&local->mtx);
1183
1184 /* busy scanning */
1185 if (local->scan_req)
1186 goto unlock;
1187
1188 /* fill internal scan request */
1189 if (!channels) {
1190 int max_n;
1191
1192 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1193 if (!local->hw.wiphy->bands[band] ||
1194 band == NL80211_BAND_6GHZ)
1195 continue;
1196
1197 max_n = local->hw.wiphy->bands[band]->n_channels;
1198 for (i = 0; i < max_n; i++) {
1199 struct ieee80211_channel *tmp_ch =
1200 &local->hw.wiphy->bands[band]->channels[i];
1201
1202 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1203 IEEE80211_CHAN_DISABLED))
1204 continue;
1205
1206 local->int_scan_req->channels[n_ch] = tmp_ch;
1207 n_ch++;
1208 }
1209 }
1210
1211 if (WARN_ON_ONCE(n_ch == 0))
1212 goto unlock;
1213
1214 local->int_scan_req->n_channels = n_ch;
1215 } else {
1216 for (i = 0; i < n_channels; i++) {
1217 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1218 IEEE80211_CHAN_DISABLED))
1219 continue;
1220
1221 local->int_scan_req->channels[n_ch] = channels[i];
1222 n_ch++;
1223 }
1224
1225 if (WARN_ON_ONCE(n_ch == 0))
1226 goto unlock;
1227
1228 local->int_scan_req->n_channels = n_ch;
1229 }
1230
1231 local->int_scan_req->ssids = &local->scan_ssid;
1232 local->int_scan_req->n_ssids = 1;
1233 local->int_scan_req->scan_width = scan_width;
1234 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1235 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1236
1237 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1238 unlock:
1239 mutex_unlock(&local->mtx);
1240 return ret;
1241 }
1242
1243 /*
1244 * Only call this function when a scan can't be queued -- under RTNL.
1245 */
ieee80211_scan_cancel(struct ieee80211_local * local)1246 void ieee80211_scan_cancel(struct ieee80211_local *local)
1247 {
1248 /*
1249 * We are canceling software scan, or deferred scan that was not
1250 * yet really started (see __ieee80211_start_scan ).
1251 *
1252 * Regarding hardware scan:
1253 * - we can not call __ieee80211_scan_completed() as when
1254 * SCAN_HW_SCANNING bit is set this function change
1255 * local->hw_scan_req to operate on 5G band, what race with
1256 * driver which can use local->hw_scan_req
1257 *
1258 * - we can not cancel scan_work since driver can schedule it
1259 * by ieee80211_scan_completed(..., true) to finish scan
1260 *
1261 * Hence we only call the cancel_hw_scan() callback, but the low-level
1262 * driver is still responsible for calling ieee80211_scan_completed()
1263 * after the scan was completed/aborted.
1264 */
1265
1266 mutex_lock(&local->mtx);
1267 if (!local->scan_req)
1268 goto out;
1269
1270 /*
1271 * We have a scan running and the driver already reported completion,
1272 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1273 * cancelled.
1274 */
1275 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1276 test_bit(SCAN_COMPLETED, &local->scanning)) {
1277 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1278 goto out;
1279 }
1280
1281 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1282 /*
1283 * Make sure that __ieee80211_scan_completed doesn't trigger a
1284 * scan on another band.
1285 */
1286 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1287 if (local->ops->cancel_hw_scan)
1288 drv_cancel_hw_scan(local,
1289 rcu_dereference_protected(local->scan_sdata,
1290 lockdep_is_held(&local->mtx)));
1291 goto out;
1292 }
1293
1294 /*
1295 * If the work is currently running, it must be blocked on
1296 * the mutex, but we'll set scan_sdata = NULL and it'll
1297 * simply exit once it acquires the mutex.
1298 */
1299 cancel_delayed_work(&local->scan_work);
1300 /* and clean up */
1301 memset(&local->scan_info, 0, sizeof(local->scan_info));
1302 __ieee80211_scan_completed(&local->hw, true);
1303 out:
1304 mutex_unlock(&local->mtx);
1305 }
1306
__ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1307 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1308 struct cfg80211_sched_scan_request *req)
1309 {
1310 struct ieee80211_local *local = sdata->local;
1311 struct ieee80211_scan_ies sched_scan_ies = {};
1312 struct cfg80211_chan_def chandef;
1313 int ret, i, iebufsz, num_bands = 0;
1314 u32 rate_masks[NUM_NL80211_BANDS] = {};
1315 u8 bands_used = 0;
1316 u8 *ie;
1317 u32 flags = 0;
1318
1319 iebufsz = local->scan_ies_len + req->ie_len;
1320
1321 lockdep_assert_held(&local->mtx);
1322
1323 if (!local->ops->sched_scan_start)
1324 return -ENOTSUPP;
1325
1326 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1327 if (local->hw.wiphy->bands[i]) {
1328 bands_used |= BIT(i);
1329 rate_masks[i] = (u32) -1;
1330 num_bands++;
1331 }
1332 }
1333
1334 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1335 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1336
1337 ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1338 if (!ie) {
1339 ret = -ENOMEM;
1340 goto out;
1341 }
1342
1343 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1344
1345 ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1346 &sched_scan_ies, req->ie,
1347 req->ie_len, bands_used, rate_masks, &chandef,
1348 flags);
1349
1350 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1351 if (ret == 0) {
1352 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1353 rcu_assign_pointer(local->sched_scan_req, req);
1354 }
1355
1356 kfree(ie);
1357
1358 out:
1359 if (ret) {
1360 /* Clean in case of failure after HW restart or upon resume. */
1361 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1362 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1363 }
1364
1365 return ret;
1366 }
1367
ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1368 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1369 struct cfg80211_sched_scan_request *req)
1370 {
1371 struct ieee80211_local *local = sdata->local;
1372 int ret;
1373
1374 mutex_lock(&local->mtx);
1375
1376 if (rcu_access_pointer(local->sched_scan_sdata)) {
1377 mutex_unlock(&local->mtx);
1378 return -EBUSY;
1379 }
1380
1381 ret = __ieee80211_request_sched_scan_start(sdata, req);
1382
1383 mutex_unlock(&local->mtx);
1384 return ret;
1385 }
1386
ieee80211_request_sched_scan_stop(struct ieee80211_local * local)1387 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1388 {
1389 struct ieee80211_sub_if_data *sched_scan_sdata;
1390 int ret = -ENOENT;
1391
1392 mutex_lock(&local->mtx);
1393
1394 if (!local->ops->sched_scan_stop) {
1395 ret = -ENOTSUPP;
1396 goto out;
1397 }
1398
1399 /* We don't want to restart sched scan anymore. */
1400 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1401
1402 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1403 lockdep_is_held(&local->mtx));
1404 if (sched_scan_sdata) {
1405 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1406 if (!ret)
1407 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1408 }
1409 out:
1410 mutex_unlock(&local->mtx);
1411
1412 return ret;
1413 }
1414
ieee80211_sched_scan_results(struct ieee80211_hw * hw)1415 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1416 {
1417 struct ieee80211_local *local = hw_to_local(hw);
1418
1419 trace_api_sched_scan_results(local);
1420
1421 cfg80211_sched_scan_results(hw->wiphy, 0);
1422 }
1423 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1424
ieee80211_sched_scan_end(struct ieee80211_local * local)1425 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1426 {
1427 mutex_lock(&local->mtx);
1428
1429 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1430 mutex_unlock(&local->mtx);
1431 return;
1432 }
1433
1434 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1435
1436 /* If sched scan was aborted by the driver. */
1437 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1438
1439 mutex_unlock(&local->mtx);
1440
1441 cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1442 }
1443
ieee80211_sched_scan_stopped_work(struct work_struct * work)1444 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1445 {
1446 struct ieee80211_local *local =
1447 container_of(work, struct ieee80211_local,
1448 sched_scan_stopped_work);
1449
1450 ieee80211_sched_scan_end(local);
1451 }
1452
ieee80211_sched_scan_stopped(struct ieee80211_hw * hw)1453 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1454 {
1455 struct ieee80211_local *local = hw_to_local(hw);
1456
1457 trace_api_sched_scan_stopped(local);
1458
1459 /*
1460 * this shouldn't really happen, so for simplicity
1461 * simply ignore it, and let mac80211 reconfigure
1462 * the sched scan later on.
1463 */
1464 if (local->in_reconfig)
1465 return;
1466
1467 schedule_work(&local->sched_scan_stopped_work);
1468 }
1469 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
1470