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 (ieee80211_is_probe_resp(mgmt->frame_control)) {
283 struct cfg80211_scan_request *scan_req;
284 struct cfg80211_sched_scan_request *sched_scan_req;
285 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
286
287 scan_req = rcu_dereference(local->scan_req);
288 sched_scan_req = rcu_dereference(local->sched_scan_req);
289
290 if (scan_req)
291 scan_req_flags = scan_req->flags;
292
293 if (sched_scan_req)
294 sched_scan_req_flags = sched_scan_req->flags;
295
296 /* ignore ProbeResp to foreign address or non-bcast (OCE)
297 * unless scanning with randomised address
298 */
299 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
300 mgmt->da) &&
301 !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
302 mgmt->da))
303 return;
304 }
305
306 channel = ieee80211_get_channel_khz(local->hw.wiphy,
307 ieee80211_rx_status_to_khz(rx_status));
308
309 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
310 return;
311
312 bss = ieee80211_bss_info_update(local, rx_status,
313 mgmt, skb->len,
314 channel);
315 if (bss)
316 ieee80211_rx_bss_put(local, bss);
317 }
318
319 static void
ieee80211_prepare_scan_chandef(struct cfg80211_chan_def * chandef,enum nl80211_bss_scan_width scan_width)320 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
321 enum nl80211_bss_scan_width scan_width)
322 {
323 memset(chandef, 0, sizeof(*chandef));
324 switch (scan_width) {
325 case NL80211_BSS_CHAN_WIDTH_5:
326 chandef->width = NL80211_CHAN_WIDTH_5;
327 break;
328 case NL80211_BSS_CHAN_WIDTH_10:
329 chandef->width = NL80211_CHAN_WIDTH_10;
330 break;
331 default:
332 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
333 break;
334 }
335 }
336
337 /* return false if no more work */
ieee80211_prep_hw_scan(struct ieee80211_sub_if_data * sdata)338 static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
339 {
340 struct ieee80211_local *local = sdata->local;
341 struct cfg80211_scan_request *req;
342 struct cfg80211_chan_def chandef;
343 u8 bands_used = 0;
344 int i, ielen, n_chans;
345 u32 flags = 0;
346
347 req = rcu_dereference_protected(local->scan_req,
348 lockdep_is_held(&local->mtx));
349
350 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
351 return false;
352
353 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
354 for (i = 0; i < req->n_channels; i++) {
355 local->hw_scan_req->req.channels[i] = req->channels[i];
356 bands_used |= BIT(req->channels[i]->band);
357 }
358
359 n_chans = req->n_channels;
360 } else {
361 do {
362 if (local->hw_scan_band == NUM_NL80211_BANDS)
363 return false;
364
365 n_chans = 0;
366
367 for (i = 0; i < req->n_channels; i++) {
368 if (req->channels[i]->band !=
369 local->hw_scan_band)
370 continue;
371 local->hw_scan_req->req.channels[n_chans] =
372 req->channels[i];
373 n_chans++;
374 bands_used |= BIT(req->channels[i]->band);
375 }
376
377 local->hw_scan_band++;
378 } while (!n_chans);
379 }
380
381 local->hw_scan_req->req.n_channels = n_chans;
382 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
383
384 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
385 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
386
387 ielen = ieee80211_build_preq_ies(sdata,
388 (u8 *)local->hw_scan_req->req.ie,
389 local->hw_scan_ies_bufsize,
390 &local->hw_scan_req->ies,
391 req->ie, req->ie_len,
392 bands_used, req->rates, &chandef,
393 flags);
394 local->hw_scan_req->req.ie_len = ielen;
395 local->hw_scan_req->req.no_cck = req->no_cck;
396 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
397 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
398 req->mac_addr_mask);
399 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
400
401 return true;
402 }
403
__ieee80211_scan_completed(struct ieee80211_hw * hw,bool aborted)404 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
405 {
406 struct ieee80211_local *local = hw_to_local(hw);
407 bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
408 bool was_scanning = local->scanning;
409 struct cfg80211_scan_request *scan_req;
410 struct ieee80211_sub_if_data *scan_sdata;
411 struct ieee80211_sub_if_data *sdata;
412
413 lockdep_assert_held(&local->mtx);
414
415 /*
416 * It's ok to abort a not-yet-running scan (that
417 * we have one at all will be verified by checking
418 * local->scan_req next), but not to complete it
419 * successfully.
420 */
421 if (WARN_ON(!local->scanning && !aborted))
422 aborted = true;
423
424 if (WARN_ON(!local->scan_req))
425 return;
426
427 scan_sdata = rcu_dereference_protected(local->scan_sdata,
428 lockdep_is_held(&local->mtx));
429
430 if (hw_scan && !aborted &&
431 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
432 ieee80211_prep_hw_scan(scan_sdata)) {
433 int rc;
434
435 rc = drv_hw_scan(local,
436 rcu_dereference_protected(local->scan_sdata,
437 lockdep_is_held(&local->mtx)),
438 local->hw_scan_req);
439
440 if (rc == 0)
441 return;
442
443 /* HW scan failed and is going to be reported as aborted,
444 * so clear old scan info.
445 */
446 memset(&local->scan_info, 0, sizeof(local->scan_info));
447 aborted = true;
448 }
449
450 kfree(local->hw_scan_req);
451 local->hw_scan_req = NULL;
452
453 scan_req = rcu_dereference_protected(local->scan_req,
454 lockdep_is_held(&local->mtx));
455
456 if (scan_req != local->int_scan_req) {
457 local->scan_info.aborted = aborted;
458 cfg80211_scan_done(scan_req, &local->scan_info);
459 }
460 RCU_INIT_POINTER(local->scan_req, NULL);
461 RCU_INIT_POINTER(local->scan_sdata, NULL);
462
463 local->scanning = 0;
464 local->scan_chandef.chan = NULL;
465
466 /* Set power back to normal operating levels. */
467 ieee80211_hw_config(local, 0);
468
469 if (!hw_scan) {
470 ieee80211_configure_filter(local);
471 drv_sw_scan_complete(local, scan_sdata);
472 ieee80211_offchannel_return(local);
473 }
474
475 ieee80211_recalc_idle(local);
476
477 ieee80211_mlme_notify_scan_completed(local);
478 ieee80211_ibss_notify_scan_completed(local);
479
480 /* Requeue all the work that might have been ignored while
481 * the scan was in progress; if there was none this will
482 * just be a no-op for the particular interface.
483 */
484 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
485 if (ieee80211_sdata_running(sdata))
486 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
487 }
488
489 if (was_scanning)
490 ieee80211_start_next_roc(local);
491 }
492
ieee80211_scan_completed(struct ieee80211_hw * hw,struct cfg80211_scan_info * info)493 void ieee80211_scan_completed(struct ieee80211_hw *hw,
494 struct cfg80211_scan_info *info)
495 {
496 struct ieee80211_local *local = hw_to_local(hw);
497
498 trace_api_scan_completed(local, info->aborted);
499
500 set_bit(SCAN_COMPLETED, &local->scanning);
501 if (info->aborted)
502 set_bit(SCAN_ABORTED, &local->scanning);
503
504 memcpy(&local->scan_info, info, sizeof(*info));
505
506 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
507 }
508 EXPORT_SYMBOL(ieee80211_scan_completed);
509
ieee80211_start_sw_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)510 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
511 struct ieee80211_sub_if_data *sdata)
512 {
513 /* Software scan is not supported in multi-channel cases */
514 if (local->use_chanctx)
515 return -EOPNOTSUPP;
516
517 /*
518 * Hardware/driver doesn't support hw_scan, so use software
519 * scanning instead. First send a nullfunc frame with power save
520 * bit on so that AP will buffer the frames for us while we are not
521 * listening, then send probe requests to each channel and wait for
522 * the responses. After all channels are scanned, tune back to the
523 * original channel and send a nullfunc frame with power save bit
524 * off to trigger the AP to send us all the buffered frames.
525 *
526 * Note that while local->sw_scanning is true everything else but
527 * nullfunc frames and probe requests will be dropped in
528 * ieee80211_tx_h_check_assoc().
529 */
530 drv_sw_scan_start(local, sdata, local->scan_addr);
531
532 local->leave_oper_channel_time = jiffies;
533 local->next_scan_state = SCAN_DECISION;
534 local->scan_channel_idx = 0;
535
536 ieee80211_offchannel_stop_vifs(local);
537
538 /* ensure nullfunc is transmitted before leaving operating channel */
539 ieee80211_flush_queues(local, NULL, false);
540
541 ieee80211_configure_filter(local);
542
543 /* We need to set power level at maximum rate for scanning. */
544 ieee80211_hw_config(local, 0);
545
546 ieee80211_queue_delayed_work(&local->hw,
547 &local->scan_work, 0);
548
549 return 0;
550 }
551
__ieee80211_can_leave_ch(struct ieee80211_sub_if_data * sdata)552 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
553 {
554 struct ieee80211_local *local = sdata->local;
555 struct ieee80211_sub_if_data *sdata_iter;
556
557 if (!ieee80211_is_radar_required(local))
558 return true;
559
560 if (!regulatory_pre_cac_allowed(local->hw.wiphy))
561 return false;
562
563 mutex_lock(&local->iflist_mtx);
564 list_for_each_entry(sdata_iter, &local->interfaces, list) {
565 if (sdata_iter->wdev.cac_started) {
566 mutex_unlock(&local->iflist_mtx);
567 return false;
568 }
569 }
570 mutex_unlock(&local->iflist_mtx);
571
572 return true;
573 }
574
ieee80211_can_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)575 static bool ieee80211_can_scan(struct ieee80211_local *local,
576 struct ieee80211_sub_if_data *sdata)
577 {
578 if (!__ieee80211_can_leave_ch(sdata))
579 return false;
580
581 if (!list_empty(&local->roc_list))
582 return false;
583
584 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
585 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
586 return false;
587
588 return true;
589 }
590
ieee80211_run_deferred_scan(struct ieee80211_local * local)591 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
592 {
593 lockdep_assert_held(&local->mtx);
594
595 if (!local->scan_req || local->scanning)
596 return;
597
598 if (!ieee80211_can_scan(local,
599 rcu_dereference_protected(
600 local->scan_sdata,
601 lockdep_is_held(&local->mtx))))
602 return;
603
604 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
605 round_jiffies_relative(0));
606 }
607
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)608 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
609 const u8 *src, const u8 *dst,
610 const u8 *ssid, size_t ssid_len,
611 const u8 *ie, size_t ie_len,
612 u32 ratemask, u32 flags, u32 tx_flags,
613 struct ieee80211_channel *channel)
614 {
615 struct sk_buff *skb;
616
617 skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
618 ssid, ssid_len,
619 ie, ie_len, flags);
620
621 if (skb) {
622 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
623 struct ieee80211_hdr *hdr = (void *)skb->data;
624 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
625 u16 sn = get_random_u32();
626
627 info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
628 hdr->seq_ctrl =
629 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
630 }
631 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
632 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
633 }
634 }
635
ieee80211_scan_state_send_probe(struct ieee80211_local * local,unsigned long * next_delay)636 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
637 unsigned long *next_delay)
638 {
639 int i;
640 struct ieee80211_sub_if_data *sdata;
641 struct cfg80211_scan_request *scan_req;
642 enum nl80211_band band = local->hw.conf.chandef.chan->band;
643 u32 flags = 0, tx_flags;
644
645 scan_req = rcu_dereference_protected(local->scan_req,
646 lockdep_is_held(&local->mtx));
647
648 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
649 if (scan_req->no_cck)
650 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
651 if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
652 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
653 if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
654 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
655
656 sdata = rcu_dereference_protected(local->scan_sdata,
657 lockdep_is_held(&local->mtx));
658
659 for (i = 0; i < scan_req->n_ssids; i++)
660 ieee80211_send_scan_probe_req(
661 sdata, local->scan_addr, scan_req->bssid,
662 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
663 scan_req->ie, scan_req->ie_len,
664 scan_req->rates[band], flags,
665 tx_flags, local->hw.conf.chandef.chan);
666
667 /*
668 * After sending probe requests, wait for probe responses
669 * on the channel.
670 */
671 *next_delay = IEEE80211_CHANNEL_TIME;
672 local->next_scan_state = SCAN_DECISION;
673 }
674
__ieee80211_start_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)675 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
676 struct cfg80211_scan_request *req)
677 {
678 struct ieee80211_local *local = sdata->local;
679 bool hw_scan = local->ops->hw_scan;
680 int rc;
681
682 lockdep_assert_held(&local->mtx);
683
684 if (local->scan_req)
685 return -EBUSY;
686
687 if (!__ieee80211_can_leave_ch(sdata))
688 return -EBUSY;
689
690 if (!ieee80211_can_scan(local, sdata)) {
691 /* wait for the work to finish/time out */
692 rcu_assign_pointer(local->scan_req, req);
693 rcu_assign_pointer(local->scan_sdata, sdata);
694 return 0;
695 }
696
697 again:
698 if (hw_scan) {
699 u8 *ies;
700
701 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
702
703 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
704 int i, n_bands = 0;
705 u8 bands_counted = 0;
706
707 for (i = 0; i < req->n_channels; i++) {
708 if (bands_counted & BIT(req->channels[i]->band))
709 continue;
710 bands_counted |= BIT(req->channels[i]->band);
711 n_bands++;
712 }
713
714 local->hw_scan_ies_bufsize *= n_bands;
715 }
716
717 local->hw_scan_req = kmalloc(
718 sizeof(*local->hw_scan_req) +
719 req->n_channels * sizeof(req->channels[0]) +
720 local->hw_scan_ies_bufsize, GFP_KERNEL);
721 if (!local->hw_scan_req)
722 return -ENOMEM;
723
724 local->hw_scan_req->req.ssids = req->ssids;
725 local->hw_scan_req->req.n_ssids = req->n_ssids;
726 ies = (u8 *)local->hw_scan_req +
727 sizeof(*local->hw_scan_req) +
728 req->n_channels * sizeof(req->channels[0]);
729 local->hw_scan_req->req.ie = ies;
730 local->hw_scan_req->req.flags = req->flags;
731 eth_broadcast_addr(local->hw_scan_req->req.bssid);
732 local->hw_scan_req->req.duration = req->duration;
733 local->hw_scan_req->req.duration_mandatory =
734 req->duration_mandatory;
735
736 local->hw_scan_band = 0;
737 local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
738 local->hw_scan_req->req.scan_6ghz_params =
739 req->scan_6ghz_params;
740 local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
741
742 /*
743 * After allocating local->hw_scan_req, we must
744 * go through until ieee80211_prep_hw_scan(), so
745 * anything that might be changed here and leave
746 * this function early must not go after this
747 * allocation.
748 */
749 }
750
751 rcu_assign_pointer(local->scan_req, req);
752 rcu_assign_pointer(local->scan_sdata, sdata);
753
754 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
755 get_random_mask_addr(local->scan_addr,
756 req->mac_addr,
757 req->mac_addr_mask);
758 else
759 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
760
761 if (hw_scan) {
762 __set_bit(SCAN_HW_SCANNING, &local->scanning);
763 } else if ((req->n_channels == 1) &&
764 (req->channels[0] == local->_oper_chandef.chan)) {
765 /*
766 * If we are scanning only on the operating channel
767 * then we do not need to stop normal activities
768 */
769 unsigned long next_delay;
770
771 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
772
773 ieee80211_recalc_idle(local);
774
775 /* Notify driver scan is starting, keep order of operations
776 * same as normal software scan, in case that matters. */
777 drv_sw_scan_start(local, sdata, local->scan_addr);
778
779 ieee80211_configure_filter(local); /* accept probe-responses */
780
781 /* We need to ensure power level is at max for scanning. */
782 ieee80211_hw_config(local, 0);
783
784 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
785 IEEE80211_CHAN_RADAR)) ||
786 !req->n_ssids) {
787 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
788 } else {
789 ieee80211_scan_state_send_probe(local, &next_delay);
790 next_delay = IEEE80211_CHANNEL_TIME;
791 }
792
793 /* Now, just wait a bit and we are all done! */
794 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
795 next_delay);
796 return 0;
797 } else {
798 /* Do normal software scan */
799 __set_bit(SCAN_SW_SCANNING, &local->scanning);
800 }
801
802 ieee80211_recalc_idle(local);
803
804 if (hw_scan) {
805 WARN_ON(!ieee80211_prep_hw_scan(sdata));
806 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
807 } else {
808 rc = ieee80211_start_sw_scan(local, sdata);
809 }
810
811 if (rc) {
812 kfree(local->hw_scan_req);
813 local->hw_scan_req = NULL;
814 local->scanning = 0;
815
816 ieee80211_recalc_idle(local);
817
818 local->scan_req = NULL;
819 RCU_INIT_POINTER(local->scan_sdata, NULL);
820 }
821
822 if (hw_scan && rc == 1) {
823 /*
824 * we can't fall back to software for P2P-GO
825 * as it must update NoA etc.
826 */
827 if (ieee80211_vif_type_p2p(&sdata->vif) ==
828 NL80211_IFTYPE_P2P_GO)
829 return -EOPNOTSUPP;
830 hw_scan = false;
831 goto again;
832 }
833
834 return rc;
835 }
836
837 static unsigned long
ieee80211_scan_get_channel_time(struct ieee80211_channel * chan)838 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
839 {
840 /*
841 * TODO: channel switching also consumes quite some time,
842 * add that delay as well to get a better estimation
843 */
844 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
845 return IEEE80211_PASSIVE_CHANNEL_TIME;
846 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
847 }
848
ieee80211_scan_state_decision(struct ieee80211_local * local,unsigned long * next_delay)849 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
850 unsigned long *next_delay)
851 {
852 bool associated = false;
853 bool tx_empty = true;
854 bool bad_latency;
855 struct ieee80211_sub_if_data *sdata;
856 struct ieee80211_channel *next_chan;
857 enum mac80211_scan_state next_scan_state;
858 struct cfg80211_scan_request *scan_req;
859
860 /*
861 * check if at least one STA interface is associated,
862 * check if at least one STA interface has pending tx frames
863 * and grab the lowest used beacon interval
864 */
865 mutex_lock(&local->iflist_mtx);
866 list_for_each_entry(sdata, &local->interfaces, list) {
867 if (!ieee80211_sdata_running(sdata))
868 continue;
869
870 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
871 if (sdata->u.mgd.associated) {
872 associated = true;
873
874 if (!qdisc_all_tx_empty(sdata->dev)) {
875 tx_empty = false;
876 break;
877 }
878 }
879 }
880 }
881 mutex_unlock(&local->iflist_mtx);
882
883 scan_req = rcu_dereference_protected(local->scan_req,
884 lockdep_is_held(&local->mtx));
885
886 next_chan = scan_req->channels[local->scan_channel_idx];
887
888 /*
889 * we're currently scanning a different channel, let's
890 * see if we can scan another channel without interfering
891 * with the current traffic situation.
892 *
893 * Keep good latency, do not stay off-channel more than 125 ms.
894 */
895
896 bad_latency = time_after(jiffies +
897 ieee80211_scan_get_channel_time(next_chan),
898 local->leave_oper_channel_time + HZ / 8);
899
900 if (associated && !tx_empty) {
901 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
902 next_scan_state = SCAN_ABORT;
903 else
904 next_scan_state = SCAN_SUSPEND;
905 } else if (associated && bad_latency) {
906 next_scan_state = SCAN_SUSPEND;
907 } else {
908 next_scan_state = SCAN_SET_CHANNEL;
909 }
910
911 local->next_scan_state = next_scan_state;
912
913 *next_delay = 0;
914 }
915
ieee80211_scan_state_set_channel(struct ieee80211_local * local,unsigned long * next_delay)916 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
917 unsigned long *next_delay)
918 {
919 int skip;
920 struct ieee80211_channel *chan;
921 enum nl80211_bss_scan_width oper_scan_width;
922 struct cfg80211_scan_request *scan_req;
923
924 scan_req = rcu_dereference_protected(local->scan_req,
925 lockdep_is_held(&local->mtx));
926
927 skip = 0;
928 chan = scan_req->channels[local->scan_channel_idx];
929
930 local->scan_chandef.chan = chan;
931 local->scan_chandef.center_freq1 = chan->center_freq;
932 local->scan_chandef.freq1_offset = chan->freq_offset;
933 local->scan_chandef.center_freq2 = 0;
934
935 /* For scanning on the S1G band, ignore scan_width (which is constant
936 * across all channels) for now since channel width is specific to each
937 * channel. Detect the required channel width here and likely revisit
938 * later. Maybe scan_width could be used to build the channel scan list?
939 */
940 if (chan->band == NL80211_BAND_S1GHZ) {
941 local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
942 goto set_channel;
943 }
944
945 switch (scan_req->scan_width) {
946 case NL80211_BSS_CHAN_WIDTH_5:
947 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
948 break;
949 case NL80211_BSS_CHAN_WIDTH_10:
950 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
951 break;
952 default:
953 case NL80211_BSS_CHAN_WIDTH_20:
954 /* If scanning on oper channel, use whatever channel-type
955 * is currently in use.
956 */
957 oper_scan_width = cfg80211_chandef_to_scan_width(
958 &local->_oper_chandef);
959 if (chan == local->_oper_chandef.chan &&
960 oper_scan_width == scan_req->scan_width)
961 local->scan_chandef = local->_oper_chandef;
962 else
963 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
964 break;
965 case NL80211_BSS_CHAN_WIDTH_1:
966 case NL80211_BSS_CHAN_WIDTH_2:
967 /* shouldn't get here, S1G handled above */
968 WARN_ON(1);
969 break;
970 }
971
972 set_channel:
973 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
974 skip = 1;
975
976 /* advance state machine to next channel/band */
977 local->scan_channel_idx++;
978
979 if (skip) {
980 /* if we skip this channel return to the decision state */
981 local->next_scan_state = SCAN_DECISION;
982 return;
983 }
984
985 /*
986 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
987 * (which unfortunately doesn't say _why_ step a) is done,
988 * but it waits for the probe delay or until a frame is
989 * received - and the received frame would update the NAV).
990 * For now, we do not support waiting until a frame is
991 * received.
992 *
993 * In any case, it is not necessary for a passive scan.
994 */
995 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
996 !scan_req->n_ssids) {
997 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
998 local->next_scan_state = SCAN_DECISION;
999 return;
1000 }
1001
1002 /* active scan, send probes */
1003 *next_delay = IEEE80211_PROBE_DELAY;
1004 local->next_scan_state = SCAN_SEND_PROBE;
1005 }
1006
ieee80211_scan_state_suspend(struct ieee80211_local * local,unsigned long * next_delay)1007 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1008 unsigned long *next_delay)
1009 {
1010 /* switch back to the operating channel */
1011 local->scan_chandef.chan = NULL;
1012 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
1013
1014 /* disable PS */
1015 ieee80211_offchannel_return(local);
1016
1017 *next_delay = HZ / 5;
1018 /* afterwards, resume scan & go to next channel */
1019 local->next_scan_state = SCAN_RESUME;
1020 }
1021
ieee80211_scan_state_resume(struct ieee80211_local * local,unsigned long * next_delay)1022 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1023 unsigned long *next_delay)
1024 {
1025 ieee80211_offchannel_stop_vifs(local);
1026
1027 if (local->ops->flush) {
1028 ieee80211_flush_queues(local, NULL, false);
1029 *next_delay = 0;
1030 } else
1031 *next_delay = HZ / 10;
1032
1033 /* remember when we left the operating channel */
1034 local->leave_oper_channel_time = jiffies;
1035
1036 /* advance to the next channel to be scanned */
1037 local->next_scan_state = SCAN_SET_CHANNEL;
1038 }
1039
ieee80211_scan_work(struct work_struct * work)1040 void ieee80211_scan_work(struct work_struct *work)
1041 {
1042 struct ieee80211_local *local =
1043 container_of(work, struct ieee80211_local, scan_work.work);
1044 struct ieee80211_sub_if_data *sdata;
1045 struct cfg80211_scan_request *scan_req;
1046 unsigned long next_delay = 0;
1047 bool aborted;
1048
1049 mutex_lock(&local->mtx);
1050
1051 if (!ieee80211_can_run_worker(local)) {
1052 aborted = true;
1053 goto out_complete;
1054 }
1055
1056 sdata = rcu_dereference_protected(local->scan_sdata,
1057 lockdep_is_held(&local->mtx));
1058 scan_req = rcu_dereference_protected(local->scan_req,
1059 lockdep_is_held(&local->mtx));
1060
1061 /* When scanning on-channel, the first-callback means completed. */
1062 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1063 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1064 goto out_complete;
1065 }
1066
1067 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1068 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1069 goto out_complete;
1070 }
1071
1072 if (!sdata || !scan_req)
1073 goto out;
1074
1075 if (!local->scanning) {
1076 int rc;
1077
1078 RCU_INIT_POINTER(local->scan_req, NULL);
1079 RCU_INIT_POINTER(local->scan_sdata, NULL);
1080
1081 rc = __ieee80211_start_scan(sdata, scan_req);
1082 if (rc) {
1083 /* need to complete scan in cfg80211 */
1084 rcu_assign_pointer(local->scan_req, scan_req);
1085 aborted = true;
1086 goto out_complete;
1087 } else
1088 goto out;
1089 }
1090
1091 /*
1092 * as long as no delay is required advance immediately
1093 * without scheduling a new work
1094 */
1095 do {
1096 if (!ieee80211_sdata_running(sdata)) {
1097 aborted = true;
1098 goto out_complete;
1099 }
1100
1101 switch (local->next_scan_state) {
1102 case SCAN_DECISION:
1103 /* if no more bands/channels left, complete scan */
1104 if (local->scan_channel_idx >= scan_req->n_channels) {
1105 aborted = false;
1106 goto out_complete;
1107 }
1108 ieee80211_scan_state_decision(local, &next_delay);
1109 break;
1110 case SCAN_SET_CHANNEL:
1111 ieee80211_scan_state_set_channel(local, &next_delay);
1112 break;
1113 case SCAN_SEND_PROBE:
1114 ieee80211_scan_state_send_probe(local, &next_delay);
1115 break;
1116 case SCAN_SUSPEND:
1117 ieee80211_scan_state_suspend(local, &next_delay);
1118 break;
1119 case SCAN_RESUME:
1120 ieee80211_scan_state_resume(local, &next_delay);
1121 break;
1122 case SCAN_ABORT:
1123 aborted = true;
1124 goto out_complete;
1125 }
1126 } while (next_delay == 0);
1127
1128 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
1129 goto out;
1130
1131 out_complete:
1132 __ieee80211_scan_completed(&local->hw, aborted);
1133 out:
1134 mutex_unlock(&local->mtx);
1135 }
1136
ieee80211_request_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)1137 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1138 struct cfg80211_scan_request *req)
1139 {
1140 int res;
1141
1142 mutex_lock(&sdata->local->mtx);
1143 res = __ieee80211_start_scan(sdata, req);
1144 mutex_unlock(&sdata->local->mtx);
1145
1146 return res;
1147 }
1148
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)1149 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1150 const u8 *ssid, u8 ssid_len,
1151 struct ieee80211_channel **channels,
1152 unsigned int n_channels,
1153 enum nl80211_bss_scan_width scan_width)
1154 {
1155 struct ieee80211_local *local = sdata->local;
1156 int ret = -EBUSY, i, n_ch = 0;
1157 enum nl80211_band band;
1158
1159 mutex_lock(&local->mtx);
1160
1161 /* busy scanning */
1162 if (local->scan_req)
1163 goto unlock;
1164
1165 /* fill internal scan request */
1166 if (!channels) {
1167 int max_n;
1168
1169 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1170 if (!local->hw.wiphy->bands[band] ||
1171 band == NL80211_BAND_6GHZ)
1172 continue;
1173
1174 max_n = local->hw.wiphy->bands[band]->n_channels;
1175 for (i = 0; i < max_n; i++) {
1176 struct ieee80211_channel *tmp_ch =
1177 &local->hw.wiphy->bands[band]->channels[i];
1178
1179 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1180 IEEE80211_CHAN_DISABLED))
1181 continue;
1182
1183 local->int_scan_req->channels[n_ch] = tmp_ch;
1184 n_ch++;
1185 }
1186 }
1187
1188 if (WARN_ON_ONCE(n_ch == 0))
1189 goto unlock;
1190
1191 local->int_scan_req->n_channels = n_ch;
1192 } else {
1193 for (i = 0; i < n_channels; i++) {
1194 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1195 IEEE80211_CHAN_DISABLED))
1196 continue;
1197
1198 local->int_scan_req->channels[n_ch] = channels[i];
1199 n_ch++;
1200 }
1201
1202 if (WARN_ON_ONCE(n_ch == 0))
1203 goto unlock;
1204
1205 local->int_scan_req->n_channels = n_ch;
1206 }
1207
1208 local->int_scan_req->ssids = &local->scan_ssid;
1209 local->int_scan_req->n_ssids = 1;
1210 local->int_scan_req->scan_width = scan_width;
1211 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1212 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1213
1214 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1215 unlock:
1216 mutex_unlock(&local->mtx);
1217 return ret;
1218 }
1219
1220 /*
1221 * Only call this function when a scan can't be queued -- under RTNL.
1222 */
ieee80211_scan_cancel(struct ieee80211_local * local)1223 void ieee80211_scan_cancel(struct ieee80211_local *local)
1224 {
1225 /*
1226 * We are canceling software scan, or deferred scan that was not
1227 * yet really started (see __ieee80211_start_scan ).
1228 *
1229 * Regarding hardware scan:
1230 * - we can not call __ieee80211_scan_completed() as when
1231 * SCAN_HW_SCANNING bit is set this function change
1232 * local->hw_scan_req to operate on 5G band, what race with
1233 * driver which can use local->hw_scan_req
1234 *
1235 * - we can not cancel scan_work since driver can schedule it
1236 * by ieee80211_scan_completed(..., true) to finish scan
1237 *
1238 * Hence we only call the cancel_hw_scan() callback, but the low-level
1239 * driver is still responsible for calling ieee80211_scan_completed()
1240 * after the scan was completed/aborted.
1241 */
1242
1243 mutex_lock(&local->mtx);
1244 if (!local->scan_req)
1245 goto out;
1246
1247 /*
1248 * We have a scan running and the driver already reported completion,
1249 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1250 * cancelled.
1251 */
1252 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1253 test_bit(SCAN_COMPLETED, &local->scanning)) {
1254 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1255 goto out;
1256 }
1257
1258 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1259 /*
1260 * Make sure that __ieee80211_scan_completed doesn't trigger a
1261 * scan on another band.
1262 */
1263 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1264 if (local->ops->cancel_hw_scan)
1265 drv_cancel_hw_scan(local,
1266 rcu_dereference_protected(local->scan_sdata,
1267 lockdep_is_held(&local->mtx)));
1268 goto out;
1269 }
1270
1271 /*
1272 * If the work is currently running, it must be blocked on
1273 * the mutex, but we'll set scan_sdata = NULL and it'll
1274 * simply exit once it acquires the mutex.
1275 */
1276 cancel_delayed_work(&local->scan_work);
1277 /* and clean up */
1278 memset(&local->scan_info, 0, sizeof(local->scan_info));
1279 __ieee80211_scan_completed(&local->hw, true);
1280 out:
1281 mutex_unlock(&local->mtx);
1282 }
1283
__ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1284 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1285 struct cfg80211_sched_scan_request *req)
1286 {
1287 struct ieee80211_local *local = sdata->local;
1288 struct ieee80211_scan_ies sched_scan_ies = {};
1289 struct cfg80211_chan_def chandef;
1290 int ret, i, iebufsz, num_bands = 0;
1291 u32 rate_masks[NUM_NL80211_BANDS] = {};
1292 u8 bands_used = 0;
1293 u8 *ie;
1294 u32 flags = 0;
1295
1296 iebufsz = local->scan_ies_len + req->ie_len;
1297
1298 lockdep_assert_held(&local->mtx);
1299
1300 if (!local->ops->sched_scan_start)
1301 return -ENOTSUPP;
1302
1303 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1304 if (local->hw.wiphy->bands[i]) {
1305 bands_used |= BIT(i);
1306 rate_masks[i] = (u32) -1;
1307 num_bands++;
1308 }
1309 }
1310
1311 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1312 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1313
1314 ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1315 if (!ie) {
1316 ret = -ENOMEM;
1317 goto out;
1318 }
1319
1320 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1321
1322 ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1323 &sched_scan_ies, req->ie,
1324 req->ie_len, bands_used, rate_masks, &chandef,
1325 flags);
1326
1327 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1328 if (ret == 0) {
1329 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1330 rcu_assign_pointer(local->sched_scan_req, req);
1331 }
1332
1333 kfree(ie);
1334
1335 out:
1336 if (ret) {
1337 /* Clean in case of failure after HW restart or upon resume. */
1338 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1339 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1340 }
1341
1342 return ret;
1343 }
1344
ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1345 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1346 struct cfg80211_sched_scan_request *req)
1347 {
1348 struct ieee80211_local *local = sdata->local;
1349 int ret;
1350
1351 mutex_lock(&local->mtx);
1352
1353 if (rcu_access_pointer(local->sched_scan_sdata)) {
1354 mutex_unlock(&local->mtx);
1355 return -EBUSY;
1356 }
1357
1358 ret = __ieee80211_request_sched_scan_start(sdata, req);
1359
1360 mutex_unlock(&local->mtx);
1361 return ret;
1362 }
1363
ieee80211_request_sched_scan_stop(struct ieee80211_local * local)1364 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1365 {
1366 struct ieee80211_sub_if_data *sched_scan_sdata;
1367 int ret = -ENOENT;
1368
1369 mutex_lock(&local->mtx);
1370
1371 if (!local->ops->sched_scan_stop) {
1372 ret = -ENOTSUPP;
1373 goto out;
1374 }
1375
1376 /* We don't want to restart sched scan anymore. */
1377 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1378
1379 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1380 lockdep_is_held(&local->mtx));
1381 if (sched_scan_sdata) {
1382 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1383 if (!ret)
1384 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1385 }
1386 out:
1387 mutex_unlock(&local->mtx);
1388
1389 return ret;
1390 }
1391
ieee80211_sched_scan_results(struct ieee80211_hw * hw)1392 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1393 {
1394 struct ieee80211_local *local = hw_to_local(hw);
1395
1396 trace_api_sched_scan_results(local);
1397
1398 cfg80211_sched_scan_results(hw->wiphy, 0);
1399 }
1400 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1401
ieee80211_sched_scan_end(struct ieee80211_local * local)1402 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1403 {
1404 mutex_lock(&local->mtx);
1405
1406 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1407 mutex_unlock(&local->mtx);
1408 return;
1409 }
1410
1411 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1412
1413 /* If sched scan was aborted by the driver. */
1414 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1415
1416 mutex_unlock(&local->mtx);
1417
1418 cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1419 }
1420
ieee80211_sched_scan_stopped_work(struct work_struct * work)1421 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1422 {
1423 struct ieee80211_local *local =
1424 container_of(work, struct ieee80211_local,
1425 sched_scan_stopped_work);
1426
1427 ieee80211_sched_scan_end(local);
1428 }
1429
ieee80211_sched_scan_stopped(struct ieee80211_hw * hw)1430 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1431 {
1432 struct ieee80211_local *local = hw_to_local(hw);
1433
1434 trace_api_sched_scan_stopped(local);
1435
1436 /*
1437 * this shouldn't really happen, so for simplicity
1438 * simply ignore it, and let mac80211 reconfigure
1439 * the sched scan later on.
1440 */
1441 if (local->in_reconfig)
1442 return;
1443
1444 schedule_work(&local->sched_scan_stopped_work);
1445 }
1446 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
1447