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) 2018-2019 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
137 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)138 ieee80211_bss_info_update(struct ieee80211_local *local,
139 struct ieee80211_rx_status *rx_status,
140 struct ieee80211_mgmt *mgmt, size_t len,
141 struct ieee80211_channel *channel)
142 {
143 bool beacon = ieee80211_is_beacon(mgmt->frame_control);
144 struct cfg80211_bss *cbss, *non_tx_cbss;
145 struct ieee80211_bss *bss, *non_tx_bss;
146 struct cfg80211_inform_bss bss_meta = {
147 .boottime_ns = rx_status->boottime_ns,
148 };
149 bool signal_valid;
150 struct ieee80211_sub_if_data *scan_sdata;
151 struct ieee802_11_elems elems;
152 size_t baselen;
153 u8 *elements;
154
155 if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
156 bss_meta.signal = 0; /* invalid signal indication */
157 else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
158 bss_meta.signal = rx_status->signal * 100;
159 else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
160 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
161
162 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
163 if (rx_status->bw == RATE_INFO_BW_5)
164 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
165 else if (rx_status->bw == RATE_INFO_BW_10)
166 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
167
168 bss_meta.chan = channel;
169
170 rcu_read_lock();
171 scan_sdata = rcu_dereference(local->scan_sdata);
172 if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
173 scan_sdata->vif.bss_conf.assoc &&
174 ieee80211_have_rx_timestamp(rx_status)) {
175 bss_meta.parent_tsf =
176 ieee80211_calculate_rx_timestamp(local, rx_status,
177 len + FCS_LEN, 24);
178 ether_addr_copy(bss_meta.parent_bssid,
179 scan_sdata->vif.bss_conf.bssid);
180 }
181 rcu_read_unlock();
182
183 cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
184 mgmt, len, GFP_ATOMIC);
185 if (!cbss)
186 return NULL;
187
188 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
189 elements = mgmt->u.probe_resp.variable;
190 baselen = offsetof(struct ieee80211_mgmt,
191 u.probe_resp.variable);
192 } else {
193 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
194 elements = mgmt->u.beacon.variable;
195 }
196
197 if (baselen > len)
198 return NULL;
199
200 ieee802_11_parse_elems(elements, len - baselen, false, &elems,
201 mgmt->bssid, cbss->bssid);
202
203 /* In case the signal is invalid update the status */
204 signal_valid = abs(channel->center_freq - cbss->channel->center_freq)
205 <= local->hw.wiphy->max_adj_channel_rssi_comp;
206 if (!signal_valid)
207 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
208
209 bss = (void *)cbss->priv;
210 ieee80211_update_bss_from_elems(local, bss, &elems, rx_status, beacon);
211
212 list_for_each_entry(non_tx_cbss, &cbss->nontrans_list, nontrans_list) {
213 non_tx_bss = (void *)non_tx_cbss->priv;
214
215 ieee80211_update_bss_from_elems(local, non_tx_bss, &elems,
216 rx_status, beacon);
217 }
218
219 return bss;
220 }
221
ieee80211_scan_accept_presp(struct ieee80211_sub_if_data * sdata,u32 scan_flags,const u8 * da)222 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
223 u32 scan_flags, const u8 *da)
224 {
225 if (!sdata)
226 return false;
227 /* accept broadcast for OCE */
228 if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
229 is_broadcast_ether_addr(da))
230 return true;
231 if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
232 return true;
233 return ether_addr_equal(da, sdata->vif.addr);
234 }
235
ieee80211_scan_rx(struct ieee80211_local * local,struct sk_buff * skb)236 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
237 {
238 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
239 struct ieee80211_sub_if_data *sdata1, *sdata2;
240 struct ieee80211_mgmt *mgmt = (void *)skb->data;
241 struct ieee80211_bss *bss;
242 struct ieee80211_channel *channel;
243
244 if (skb->len < 24 ||
245 (!ieee80211_is_probe_resp(mgmt->frame_control) &&
246 !ieee80211_is_beacon(mgmt->frame_control)))
247 return;
248
249 sdata1 = rcu_dereference(local->scan_sdata);
250 sdata2 = rcu_dereference(local->sched_scan_sdata);
251
252 if (likely(!sdata1 && !sdata2))
253 return;
254
255 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
256 struct cfg80211_scan_request *scan_req;
257 struct cfg80211_sched_scan_request *sched_scan_req;
258 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
259
260 scan_req = rcu_dereference(local->scan_req);
261 sched_scan_req = rcu_dereference(local->sched_scan_req);
262
263 if (scan_req)
264 scan_req_flags = scan_req->flags;
265
266 if (sched_scan_req)
267 sched_scan_req_flags = sched_scan_req->flags;
268
269 /* ignore ProbeResp to foreign address or non-bcast (OCE)
270 * unless scanning with randomised address
271 */
272 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
273 mgmt->da) &&
274 !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
275 mgmt->da))
276 return;
277 }
278
279 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
280
281 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
282 return;
283
284 bss = ieee80211_bss_info_update(local, rx_status,
285 mgmt, skb->len,
286 channel);
287 if (bss)
288 ieee80211_rx_bss_put(local, bss);
289 }
290
291 static void
ieee80211_prepare_scan_chandef(struct cfg80211_chan_def * chandef,enum nl80211_bss_scan_width scan_width)292 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
293 enum nl80211_bss_scan_width scan_width)
294 {
295 memset(chandef, 0, sizeof(*chandef));
296 switch (scan_width) {
297 case NL80211_BSS_CHAN_WIDTH_5:
298 chandef->width = NL80211_CHAN_WIDTH_5;
299 break;
300 case NL80211_BSS_CHAN_WIDTH_10:
301 chandef->width = NL80211_CHAN_WIDTH_10;
302 break;
303 default:
304 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
305 break;
306 }
307 }
308
309 /* return false if no more work */
ieee80211_prep_hw_scan(struct ieee80211_local * local)310 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
311 {
312 struct cfg80211_scan_request *req;
313 struct cfg80211_chan_def chandef;
314 u8 bands_used = 0;
315 int i, ielen, n_chans;
316 u32 flags = 0;
317
318 req = rcu_dereference_protected(local->scan_req,
319 lockdep_is_held(&local->mtx));
320
321 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
322 return false;
323
324 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
325 for (i = 0; i < req->n_channels; i++) {
326 local->hw_scan_req->req.channels[i] = req->channels[i];
327 bands_used |= BIT(req->channels[i]->band);
328 }
329
330 n_chans = req->n_channels;
331 } else {
332 do {
333 if (local->hw_scan_band == NUM_NL80211_BANDS)
334 return false;
335
336 n_chans = 0;
337
338 for (i = 0; i < req->n_channels; i++) {
339 if (req->channels[i]->band !=
340 local->hw_scan_band)
341 continue;
342 local->hw_scan_req->req.channels[n_chans] =
343 req->channels[i];
344 n_chans++;
345 bands_used |= BIT(req->channels[i]->band);
346 }
347
348 local->hw_scan_band++;
349 } while (!n_chans);
350 }
351
352 local->hw_scan_req->req.n_channels = n_chans;
353 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
354
355 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
356 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
357
358 ielen = ieee80211_build_preq_ies(local,
359 (u8 *)local->hw_scan_req->req.ie,
360 local->hw_scan_ies_bufsize,
361 &local->hw_scan_req->ies,
362 req->ie, req->ie_len,
363 bands_used, req->rates, &chandef,
364 flags);
365 local->hw_scan_req->req.ie_len = ielen;
366 local->hw_scan_req->req.no_cck = req->no_cck;
367 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
368 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
369 req->mac_addr_mask);
370 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
371
372 return true;
373 }
374
__ieee80211_scan_completed(struct ieee80211_hw * hw,bool aborted)375 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
376 {
377 struct ieee80211_local *local = hw_to_local(hw);
378 bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
379 bool was_scanning = local->scanning;
380 struct cfg80211_scan_request *scan_req;
381 struct ieee80211_sub_if_data *scan_sdata;
382 struct ieee80211_sub_if_data *sdata;
383
384 lockdep_assert_held(&local->mtx);
385
386 /*
387 * It's ok to abort a not-yet-running scan (that
388 * we have one at all will be verified by checking
389 * local->scan_req next), but not to complete it
390 * successfully.
391 */
392 if (WARN_ON(!local->scanning && !aborted))
393 aborted = true;
394
395 if (WARN_ON(!local->scan_req))
396 return;
397
398 if (hw_scan && !aborted &&
399 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
400 ieee80211_prep_hw_scan(local)) {
401 int rc;
402
403 rc = drv_hw_scan(local,
404 rcu_dereference_protected(local->scan_sdata,
405 lockdep_is_held(&local->mtx)),
406 local->hw_scan_req);
407
408 if (rc == 0)
409 return;
410
411 /* HW scan failed and is going to be reported as aborted,
412 * so clear old scan info.
413 */
414 memset(&local->scan_info, 0, sizeof(local->scan_info));
415 aborted = true;
416 }
417
418 kfree(local->hw_scan_req);
419 local->hw_scan_req = NULL;
420
421 scan_req = rcu_dereference_protected(local->scan_req,
422 lockdep_is_held(&local->mtx));
423
424 if (scan_req != local->int_scan_req) {
425 local->scan_info.aborted = aborted;
426 cfg80211_scan_done(scan_req, &local->scan_info);
427 }
428 RCU_INIT_POINTER(local->scan_req, NULL);
429
430 scan_sdata = rcu_dereference_protected(local->scan_sdata,
431 lockdep_is_held(&local->mtx));
432 RCU_INIT_POINTER(local->scan_sdata, NULL);
433
434 local->scanning = 0;
435 local->scan_chandef.chan = NULL;
436
437 /* Set power back to normal operating levels. */
438 ieee80211_hw_config(local, 0);
439
440 if (!hw_scan) {
441 ieee80211_configure_filter(local);
442 drv_sw_scan_complete(local, scan_sdata);
443 ieee80211_offchannel_return(local);
444 }
445
446 ieee80211_recalc_idle(local);
447
448 ieee80211_mlme_notify_scan_completed(local);
449 ieee80211_ibss_notify_scan_completed(local);
450
451 /* Requeue all the work that might have been ignored while
452 * the scan was in progress; if there was none this will
453 * just be a no-op for the particular interface.
454 */
455 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
456 if (ieee80211_sdata_running(sdata))
457 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
458 }
459
460 if (was_scanning)
461 ieee80211_start_next_roc(local);
462 }
463
ieee80211_scan_completed(struct ieee80211_hw * hw,struct cfg80211_scan_info * info)464 void ieee80211_scan_completed(struct ieee80211_hw *hw,
465 struct cfg80211_scan_info *info)
466 {
467 struct ieee80211_local *local = hw_to_local(hw);
468
469 trace_api_scan_completed(local, info->aborted);
470
471 set_bit(SCAN_COMPLETED, &local->scanning);
472 if (info->aborted)
473 set_bit(SCAN_ABORTED, &local->scanning);
474
475 memcpy(&local->scan_info, info, sizeof(*info));
476
477 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
478 }
479 EXPORT_SYMBOL(ieee80211_scan_completed);
480
ieee80211_start_sw_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)481 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
482 struct ieee80211_sub_if_data *sdata)
483 {
484 /* Software scan is not supported in multi-channel cases */
485 if (local->use_chanctx)
486 return -EOPNOTSUPP;
487
488 /*
489 * Hardware/driver doesn't support hw_scan, so use software
490 * scanning instead. First send a nullfunc frame with power save
491 * bit on so that AP will buffer the frames for us while we are not
492 * listening, then send probe requests to each channel and wait for
493 * the responses. After all channels are scanned, tune back to the
494 * original channel and send a nullfunc frame with power save bit
495 * off to trigger the AP to send us all the buffered frames.
496 *
497 * Note that while local->sw_scanning is true everything else but
498 * nullfunc frames and probe requests will be dropped in
499 * ieee80211_tx_h_check_assoc().
500 */
501 drv_sw_scan_start(local, sdata, local->scan_addr);
502
503 local->leave_oper_channel_time = jiffies;
504 local->next_scan_state = SCAN_DECISION;
505 local->scan_channel_idx = 0;
506
507 ieee80211_offchannel_stop_vifs(local);
508
509 /* ensure nullfunc is transmitted before leaving operating channel */
510 ieee80211_flush_queues(local, NULL, false);
511
512 ieee80211_configure_filter(local);
513
514 /* We need to set power level at maximum rate for scanning. */
515 ieee80211_hw_config(local, 0);
516
517 ieee80211_queue_delayed_work(&local->hw,
518 &local->scan_work, 0);
519
520 return 0;
521 }
522
__ieee80211_can_leave_ch(struct ieee80211_sub_if_data * sdata)523 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
524 {
525 struct ieee80211_local *local = sdata->local;
526 struct ieee80211_sub_if_data *sdata_iter;
527
528 if (!ieee80211_is_radar_required(local))
529 return true;
530
531 if (!regulatory_pre_cac_allowed(local->hw.wiphy))
532 return false;
533
534 mutex_lock(&local->iflist_mtx);
535 list_for_each_entry(sdata_iter, &local->interfaces, list) {
536 if (sdata_iter->wdev.cac_started) {
537 mutex_unlock(&local->iflist_mtx);
538 return false;
539 }
540 }
541 mutex_unlock(&local->iflist_mtx);
542
543 return true;
544 }
545
ieee80211_can_scan(struct ieee80211_local * local,struct ieee80211_sub_if_data * sdata)546 static bool ieee80211_can_scan(struct ieee80211_local *local,
547 struct ieee80211_sub_if_data *sdata)
548 {
549 if (!__ieee80211_can_leave_ch(sdata))
550 return false;
551
552 if (!list_empty(&local->roc_list))
553 return false;
554
555 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
556 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
557 return false;
558
559 return true;
560 }
561
ieee80211_run_deferred_scan(struct ieee80211_local * local)562 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
563 {
564 lockdep_assert_held(&local->mtx);
565
566 if (!local->scan_req || local->scanning)
567 return;
568
569 if (!ieee80211_can_scan(local,
570 rcu_dereference_protected(
571 local->scan_sdata,
572 lockdep_is_held(&local->mtx))))
573 return;
574
575 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
576 round_jiffies_relative(0));
577 }
578
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)579 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
580 const u8 *src, const u8 *dst,
581 const u8 *ssid, size_t ssid_len,
582 const u8 *ie, size_t ie_len,
583 u32 ratemask, u32 flags, u32 tx_flags,
584 struct ieee80211_channel *channel)
585 {
586 struct sk_buff *skb;
587 u32 txdata_flags = 0;
588
589 skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
590 ssid, ssid_len,
591 ie, ie_len, flags);
592
593 if (skb) {
594 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
595 struct ieee80211_hdr *hdr = (void *)skb->data;
596 u16 sn = get_random_u32();
597
598 txdata_flags |= IEEE80211_TX_NO_SEQNO;
599 hdr->seq_ctrl =
600 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
601 }
602 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
603 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band,
604 txdata_flags);
605 }
606 }
607
ieee80211_scan_state_send_probe(struct ieee80211_local * local,unsigned long * next_delay)608 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
609 unsigned long *next_delay)
610 {
611 int i;
612 struct ieee80211_sub_if_data *sdata;
613 struct cfg80211_scan_request *scan_req;
614 enum nl80211_band band = local->hw.conf.chandef.chan->band;
615 u32 flags = 0, tx_flags;
616
617 scan_req = rcu_dereference_protected(local->scan_req,
618 lockdep_is_held(&local->mtx));
619
620 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
621 if (scan_req->no_cck)
622 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
623 if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
624 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
625 if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
626 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
627
628 sdata = rcu_dereference_protected(local->scan_sdata,
629 lockdep_is_held(&local->mtx));
630
631 for (i = 0; i < scan_req->n_ssids; i++)
632 ieee80211_send_scan_probe_req(
633 sdata, local->scan_addr, scan_req->bssid,
634 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
635 scan_req->ie, scan_req->ie_len,
636 scan_req->rates[band], flags,
637 tx_flags, local->hw.conf.chandef.chan);
638
639 /*
640 * After sending probe requests, wait for probe responses
641 * on the channel.
642 */
643 *next_delay = IEEE80211_CHANNEL_TIME;
644 local->next_scan_state = SCAN_DECISION;
645 }
646
__ieee80211_start_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)647 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
648 struct cfg80211_scan_request *req)
649 {
650 struct ieee80211_local *local = sdata->local;
651 bool hw_scan = local->ops->hw_scan;
652 int rc;
653
654 lockdep_assert_held(&local->mtx);
655
656 if (local->scan_req)
657 return -EBUSY;
658
659 if (!__ieee80211_can_leave_ch(sdata))
660 return -EBUSY;
661
662 if (!ieee80211_can_scan(local, sdata)) {
663 /* wait for the work to finish/time out */
664 rcu_assign_pointer(local->scan_req, req);
665 rcu_assign_pointer(local->scan_sdata, sdata);
666 return 0;
667 }
668
669 again:
670 if (hw_scan) {
671 u8 *ies;
672
673 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
674
675 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
676 int i, n_bands = 0;
677 u8 bands_counted = 0;
678
679 for (i = 0; i < req->n_channels; i++) {
680 if (bands_counted & BIT(req->channels[i]->band))
681 continue;
682 bands_counted |= BIT(req->channels[i]->band);
683 n_bands++;
684 }
685
686 local->hw_scan_ies_bufsize *= n_bands;
687 }
688
689 local->hw_scan_req = kmalloc(
690 sizeof(*local->hw_scan_req) +
691 req->n_channels * sizeof(req->channels[0]) +
692 local->hw_scan_ies_bufsize, GFP_KERNEL);
693 if (!local->hw_scan_req)
694 return -ENOMEM;
695
696 local->hw_scan_req->req.ssids = req->ssids;
697 local->hw_scan_req->req.n_ssids = req->n_ssids;
698 ies = (u8 *)local->hw_scan_req +
699 sizeof(*local->hw_scan_req) +
700 req->n_channels * sizeof(req->channels[0]);
701 local->hw_scan_req->req.ie = ies;
702 local->hw_scan_req->req.flags = req->flags;
703 eth_broadcast_addr(local->hw_scan_req->req.bssid);
704 local->hw_scan_req->req.duration = req->duration;
705 local->hw_scan_req->req.duration_mandatory =
706 req->duration_mandatory;
707
708 local->hw_scan_band = 0;
709
710 /*
711 * After allocating local->hw_scan_req, we must
712 * go through until ieee80211_prep_hw_scan(), so
713 * anything that might be changed here and leave
714 * this function early must not go after this
715 * allocation.
716 */
717 }
718
719 rcu_assign_pointer(local->scan_req, req);
720 rcu_assign_pointer(local->scan_sdata, sdata);
721
722 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
723 get_random_mask_addr(local->scan_addr,
724 req->mac_addr,
725 req->mac_addr_mask);
726 else
727 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
728
729 if (hw_scan) {
730 __set_bit(SCAN_HW_SCANNING, &local->scanning);
731 } else if ((req->n_channels == 1) &&
732 (req->channels[0] == local->_oper_chandef.chan)) {
733 /*
734 * If we are scanning only on the operating channel
735 * then we do not need to stop normal activities
736 */
737 unsigned long next_delay;
738
739 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
740
741 ieee80211_recalc_idle(local);
742
743 /* Notify driver scan is starting, keep order of operations
744 * same as normal software scan, in case that matters. */
745 drv_sw_scan_start(local, sdata, local->scan_addr);
746
747 ieee80211_configure_filter(local); /* accept probe-responses */
748
749 /* We need to ensure power level is at max for scanning. */
750 ieee80211_hw_config(local, 0);
751
752 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
753 IEEE80211_CHAN_RADAR)) ||
754 !req->n_ssids) {
755 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
756 } else {
757 ieee80211_scan_state_send_probe(local, &next_delay);
758 next_delay = IEEE80211_CHANNEL_TIME;
759 }
760
761 /* Now, just wait a bit and we are all done! */
762 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
763 next_delay);
764 return 0;
765 } else {
766 /* Do normal software scan */
767 __set_bit(SCAN_SW_SCANNING, &local->scanning);
768 }
769
770 ieee80211_recalc_idle(local);
771
772 if (hw_scan) {
773 WARN_ON(!ieee80211_prep_hw_scan(local));
774 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
775 } else {
776 rc = ieee80211_start_sw_scan(local, sdata);
777 }
778
779 if (rc) {
780 kfree(local->hw_scan_req);
781 local->hw_scan_req = NULL;
782 local->scanning = 0;
783
784 ieee80211_recalc_idle(local);
785
786 local->scan_req = NULL;
787 RCU_INIT_POINTER(local->scan_sdata, NULL);
788 }
789
790 if (hw_scan && rc == 1) {
791 /*
792 * we can't fall back to software for P2P-GO
793 * as it must update NoA etc.
794 */
795 if (ieee80211_vif_type_p2p(&sdata->vif) ==
796 NL80211_IFTYPE_P2P_GO)
797 return -EOPNOTSUPP;
798 hw_scan = false;
799 goto again;
800 }
801
802 return rc;
803 }
804
805 static unsigned long
ieee80211_scan_get_channel_time(struct ieee80211_channel * chan)806 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
807 {
808 /*
809 * TODO: channel switching also consumes quite some time,
810 * add that delay as well to get a better estimation
811 */
812 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
813 return IEEE80211_PASSIVE_CHANNEL_TIME;
814 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
815 }
816
ieee80211_scan_state_decision(struct ieee80211_local * local,unsigned long * next_delay)817 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
818 unsigned long *next_delay)
819 {
820 bool associated = false;
821 bool tx_empty = true;
822 bool bad_latency;
823 struct ieee80211_sub_if_data *sdata;
824 struct ieee80211_channel *next_chan;
825 enum mac80211_scan_state next_scan_state;
826 struct cfg80211_scan_request *scan_req;
827
828 /*
829 * check if at least one STA interface is associated,
830 * check if at least one STA interface has pending tx frames
831 * and grab the lowest used beacon interval
832 */
833 mutex_lock(&local->iflist_mtx);
834 list_for_each_entry(sdata, &local->interfaces, list) {
835 if (!ieee80211_sdata_running(sdata))
836 continue;
837
838 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
839 if (sdata->u.mgd.associated) {
840 associated = true;
841
842 if (!qdisc_all_tx_empty(sdata->dev)) {
843 tx_empty = false;
844 break;
845 }
846 }
847 }
848 }
849 mutex_unlock(&local->iflist_mtx);
850
851 scan_req = rcu_dereference_protected(local->scan_req,
852 lockdep_is_held(&local->mtx));
853
854 next_chan = scan_req->channels[local->scan_channel_idx];
855
856 /*
857 * we're currently scanning a different channel, let's
858 * see if we can scan another channel without interfering
859 * with the current traffic situation.
860 *
861 * Keep good latency, do not stay off-channel more than 125 ms.
862 */
863
864 bad_latency = time_after(jiffies +
865 ieee80211_scan_get_channel_time(next_chan),
866 local->leave_oper_channel_time + HZ / 8);
867
868 if (associated && !tx_empty) {
869 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
870 next_scan_state = SCAN_ABORT;
871 else
872 next_scan_state = SCAN_SUSPEND;
873 } else if (associated && bad_latency) {
874 next_scan_state = SCAN_SUSPEND;
875 } else {
876 next_scan_state = SCAN_SET_CHANNEL;
877 }
878
879 local->next_scan_state = next_scan_state;
880
881 *next_delay = 0;
882 }
883
ieee80211_scan_state_set_channel(struct ieee80211_local * local,unsigned long * next_delay)884 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
885 unsigned long *next_delay)
886 {
887 int skip;
888 struct ieee80211_channel *chan;
889 enum nl80211_bss_scan_width oper_scan_width;
890 struct cfg80211_scan_request *scan_req;
891
892 scan_req = rcu_dereference_protected(local->scan_req,
893 lockdep_is_held(&local->mtx));
894
895 skip = 0;
896 chan = scan_req->channels[local->scan_channel_idx];
897
898 local->scan_chandef.chan = chan;
899 local->scan_chandef.center_freq1 = chan->center_freq;
900 local->scan_chandef.center_freq2 = 0;
901 switch (scan_req->scan_width) {
902 case NL80211_BSS_CHAN_WIDTH_5:
903 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
904 break;
905 case NL80211_BSS_CHAN_WIDTH_10:
906 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
907 break;
908 case NL80211_BSS_CHAN_WIDTH_20:
909 /* If scanning on oper channel, use whatever channel-type
910 * is currently in use.
911 */
912 oper_scan_width = cfg80211_chandef_to_scan_width(
913 &local->_oper_chandef);
914 if (chan == local->_oper_chandef.chan &&
915 oper_scan_width == scan_req->scan_width)
916 local->scan_chandef = local->_oper_chandef;
917 else
918 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
919 break;
920 }
921
922 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
923 skip = 1;
924
925 /* advance state machine to next channel/band */
926 local->scan_channel_idx++;
927
928 if (skip) {
929 /* if we skip this channel return to the decision state */
930 local->next_scan_state = SCAN_DECISION;
931 return;
932 }
933
934 /*
935 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
936 * (which unfortunately doesn't say _why_ step a) is done,
937 * but it waits for the probe delay or until a frame is
938 * received - and the received frame would update the NAV).
939 * For now, we do not support waiting until a frame is
940 * received.
941 *
942 * In any case, it is not necessary for a passive scan.
943 */
944 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
945 !scan_req->n_ssids) {
946 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
947 local->next_scan_state = SCAN_DECISION;
948 return;
949 }
950
951 /* active scan, send probes */
952 *next_delay = IEEE80211_PROBE_DELAY;
953 local->next_scan_state = SCAN_SEND_PROBE;
954 }
955
ieee80211_scan_state_suspend(struct ieee80211_local * local,unsigned long * next_delay)956 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
957 unsigned long *next_delay)
958 {
959 /* switch back to the operating channel */
960 local->scan_chandef.chan = NULL;
961 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
962
963 /* disable PS */
964 ieee80211_offchannel_return(local);
965
966 *next_delay = HZ / 5;
967 /* afterwards, resume scan & go to next channel */
968 local->next_scan_state = SCAN_RESUME;
969 }
970
ieee80211_scan_state_resume(struct ieee80211_local * local,unsigned long * next_delay)971 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
972 unsigned long *next_delay)
973 {
974 ieee80211_offchannel_stop_vifs(local);
975
976 if (local->ops->flush) {
977 ieee80211_flush_queues(local, NULL, false);
978 *next_delay = 0;
979 } else
980 *next_delay = HZ / 10;
981
982 /* remember when we left the operating channel */
983 local->leave_oper_channel_time = jiffies;
984
985 /* advance to the next channel to be scanned */
986 local->next_scan_state = SCAN_SET_CHANNEL;
987 }
988
ieee80211_scan_work(struct work_struct * work)989 void ieee80211_scan_work(struct work_struct *work)
990 {
991 struct ieee80211_local *local =
992 container_of(work, struct ieee80211_local, scan_work.work);
993 struct ieee80211_sub_if_data *sdata;
994 struct cfg80211_scan_request *scan_req;
995 unsigned long next_delay = 0;
996 bool aborted;
997
998 mutex_lock(&local->mtx);
999
1000 if (!ieee80211_can_run_worker(local)) {
1001 aborted = true;
1002 goto out_complete;
1003 }
1004
1005 sdata = rcu_dereference_protected(local->scan_sdata,
1006 lockdep_is_held(&local->mtx));
1007 scan_req = rcu_dereference_protected(local->scan_req,
1008 lockdep_is_held(&local->mtx));
1009
1010 /* When scanning on-channel, the first-callback means completed. */
1011 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1012 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1013 goto out_complete;
1014 }
1015
1016 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1017 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1018 goto out_complete;
1019 }
1020
1021 if (!sdata || !scan_req)
1022 goto out;
1023
1024 if (!local->scanning) {
1025 int rc;
1026
1027 RCU_INIT_POINTER(local->scan_req, NULL);
1028 RCU_INIT_POINTER(local->scan_sdata, NULL);
1029
1030 rc = __ieee80211_start_scan(sdata, scan_req);
1031 if (rc) {
1032 /* need to complete scan in cfg80211 */
1033 rcu_assign_pointer(local->scan_req, scan_req);
1034 aborted = true;
1035 goto out_complete;
1036 } else
1037 goto out;
1038 }
1039
1040 /*
1041 * as long as no delay is required advance immediately
1042 * without scheduling a new work
1043 */
1044 do {
1045 if (!ieee80211_sdata_running(sdata)) {
1046 aborted = true;
1047 goto out_complete;
1048 }
1049
1050 switch (local->next_scan_state) {
1051 case SCAN_DECISION:
1052 /* if no more bands/channels left, complete scan */
1053 if (local->scan_channel_idx >= scan_req->n_channels) {
1054 aborted = false;
1055 goto out_complete;
1056 }
1057 ieee80211_scan_state_decision(local, &next_delay);
1058 break;
1059 case SCAN_SET_CHANNEL:
1060 ieee80211_scan_state_set_channel(local, &next_delay);
1061 break;
1062 case SCAN_SEND_PROBE:
1063 ieee80211_scan_state_send_probe(local, &next_delay);
1064 break;
1065 case SCAN_SUSPEND:
1066 ieee80211_scan_state_suspend(local, &next_delay);
1067 break;
1068 case SCAN_RESUME:
1069 ieee80211_scan_state_resume(local, &next_delay);
1070 break;
1071 case SCAN_ABORT:
1072 aborted = true;
1073 goto out_complete;
1074 }
1075 } while (next_delay == 0);
1076
1077 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
1078 goto out;
1079
1080 out_complete:
1081 __ieee80211_scan_completed(&local->hw, aborted);
1082 out:
1083 mutex_unlock(&local->mtx);
1084 }
1085
ieee80211_request_scan(struct ieee80211_sub_if_data * sdata,struct cfg80211_scan_request * req)1086 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1087 struct cfg80211_scan_request *req)
1088 {
1089 int res;
1090
1091 mutex_lock(&sdata->local->mtx);
1092 res = __ieee80211_start_scan(sdata, req);
1093 mutex_unlock(&sdata->local->mtx);
1094
1095 return res;
1096 }
1097
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)1098 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1099 const u8 *ssid, u8 ssid_len,
1100 struct ieee80211_channel **channels,
1101 unsigned int n_channels,
1102 enum nl80211_bss_scan_width scan_width)
1103 {
1104 struct ieee80211_local *local = sdata->local;
1105 int ret = -EBUSY, i, n_ch = 0;
1106 enum nl80211_band band;
1107
1108 mutex_lock(&local->mtx);
1109
1110 /* busy scanning */
1111 if (local->scan_req)
1112 goto unlock;
1113
1114 /* fill internal scan request */
1115 if (!channels) {
1116 int max_n;
1117
1118 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1119 if (!local->hw.wiphy->bands[band])
1120 continue;
1121
1122 max_n = local->hw.wiphy->bands[band]->n_channels;
1123 for (i = 0; i < max_n; i++) {
1124 struct ieee80211_channel *tmp_ch =
1125 &local->hw.wiphy->bands[band]->channels[i];
1126
1127 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1128 IEEE80211_CHAN_DISABLED))
1129 continue;
1130
1131 local->int_scan_req->channels[n_ch] = tmp_ch;
1132 n_ch++;
1133 }
1134 }
1135
1136 if (WARN_ON_ONCE(n_ch == 0))
1137 goto unlock;
1138
1139 local->int_scan_req->n_channels = n_ch;
1140 } else {
1141 for (i = 0; i < n_channels; i++) {
1142 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1143 IEEE80211_CHAN_DISABLED))
1144 continue;
1145
1146 local->int_scan_req->channels[n_ch] = channels[i];
1147 n_ch++;
1148 }
1149
1150 if (WARN_ON_ONCE(n_ch == 0))
1151 goto unlock;
1152
1153 local->int_scan_req->n_channels = n_ch;
1154 }
1155
1156 local->int_scan_req->ssids = &local->scan_ssid;
1157 local->int_scan_req->n_ssids = 1;
1158 local->int_scan_req->scan_width = scan_width;
1159 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1160 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1161
1162 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1163 unlock:
1164 mutex_unlock(&local->mtx);
1165 return ret;
1166 }
1167
1168 /*
1169 * Only call this function when a scan can't be queued -- under RTNL.
1170 */
ieee80211_scan_cancel(struct ieee80211_local * local)1171 void ieee80211_scan_cancel(struct ieee80211_local *local)
1172 {
1173 /*
1174 * We are canceling software scan, or deferred scan that was not
1175 * yet really started (see __ieee80211_start_scan ).
1176 *
1177 * Regarding hardware scan:
1178 * - we can not call __ieee80211_scan_completed() as when
1179 * SCAN_HW_SCANNING bit is set this function change
1180 * local->hw_scan_req to operate on 5G band, what race with
1181 * driver which can use local->hw_scan_req
1182 *
1183 * - we can not cancel scan_work since driver can schedule it
1184 * by ieee80211_scan_completed(..., true) to finish scan
1185 *
1186 * Hence we only call the cancel_hw_scan() callback, but the low-level
1187 * driver is still responsible for calling ieee80211_scan_completed()
1188 * after the scan was completed/aborted.
1189 */
1190
1191 mutex_lock(&local->mtx);
1192 if (!local->scan_req)
1193 goto out;
1194
1195 /*
1196 * We have a scan running and the driver already reported completion,
1197 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1198 * cancelled.
1199 */
1200 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1201 test_bit(SCAN_COMPLETED, &local->scanning)) {
1202 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1203 goto out;
1204 }
1205
1206 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1207 /*
1208 * Make sure that __ieee80211_scan_completed doesn't trigger a
1209 * scan on another band.
1210 */
1211 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1212 if (local->ops->cancel_hw_scan)
1213 drv_cancel_hw_scan(local,
1214 rcu_dereference_protected(local->scan_sdata,
1215 lockdep_is_held(&local->mtx)));
1216 goto out;
1217 }
1218
1219 /*
1220 * If the work is currently running, it must be blocked on
1221 * the mutex, but we'll set scan_sdata = NULL and it'll
1222 * simply exit once it acquires the mutex.
1223 */
1224 cancel_delayed_work(&local->scan_work);
1225 /* and clean up */
1226 memset(&local->scan_info, 0, sizeof(local->scan_info));
1227 __ieee80211_scan_completed(&local->hw, true);
1228 out:
1229 mutex_unlock(&local->mtx);
1230 }
1231
__ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1232 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1233 struct cfg80211_sched_scan_request *req)
1234 {
1235 struct ieee80211_local *local = sdata->local;
1236 struct ieee80211_scan_ies sched_scan_ies = {};
1237 struct cfg80211_chan_def chandef;
1238 int ret, i, iebufsz, num_bands = 0;
1239 u32 rate_masks[NUM_NL80211_BANDS] = {};
1240 u8 bands_used = 0;
1241 u8 *ie;
1242 u32 flags = 0;
1243
1244 iebufsz = local->scan_ies_len + req->ie_len;
1245
1246 lockdep_assert_held(&local->mtx);
1247
1248 if (!local->ops->sched_scan_start)
1249 return -ENOTSUPP;
1250
1251 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1252 if (local->hw.wiphy->bands[i]) {
1253 bands_used |= BIT(i);
1254 rate_masks[i] = (u32) -1;
1255 num_bands++;
1256 }
1257 }
1258
1259 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1260 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1261
1262 ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1263 if (!ie) {
1264 ret = -ENOMEM;
1265 goto out;
1266 }
1267
1268 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1269
1270 ieee80211_build_preq_ies(local, ie, num_bands * iebufsz,
1271 &sched_scan_ies, req->ie,
1272 req->ie_len, bands_used, rate_masks, &chandef,
1273 flags);
1274
1275 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1276 if (ret == 0) {
1277 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1278 rcu_assign_pointer(local->sched_scan_req, req);
1279 }
1280
1281 kfree(ie);
1282
1283 out:
1284 if (ret) {
1285 /* Clean in case of failure after HW restart or upon resume. */
1286 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1287 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1288 }
1289
1290 return ret;
1291 }
1292
ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data * sdata,struct cfg80211_sched_scan_request * req)1293 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1294 struct cfg80211_sched_scan_request *req)
1295 {
1296 struct ieee80211_local *local = sdata->local;
1297 int ret;
1298
1299 mutex_lock(&local->mtx);
1300
1301 if (rcu_access_pointer(local->sched_scan_sdata)) {
1302 mutex_unlock(&local->mtx);
1303 return -EBUSY;
1304 }
1305
1306 ret = __ieee80211_request_sched_scan_start(sdata, req);
1307
1308 mutex_unlock(&local->mtx);
1309 return ret;
1310 }
1311
ieee80211_request_sched_scan_stop(struct ieee80211_local * local)1312 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1313 {
1314 struct ieee80211_sub_if_data *sched_scan_sdata;
1315 int ret = -ENOENT;
1316
1317 mutex_lock(&local->mtx);
1318
1319 if (!local->ops->sched_scan_stop) {
1320 ret = -ENOTSUPP;
1321 goto out;
1322 }
1323
1324 /* We don't want to restart sched scan anymore. */
1325 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1326
1327 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1328 lockdep_is_held(&local->mtx));
1329 if (sched_scan_sdata) {
1330 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1331 if (!ret)
1332 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1333 }
1334 out:
1335 mutex_unlock(&local->mtx);
1336
1337 return ret;
1338 }
1339
ieee80211_sched_scan_results(struct ieee80211_hw * hw)1340 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1341 {
1342 struct ieee80211_local *local = hw_to_local(hw);
1343
1344 trace_api_sched_scan_results(local);
1345
1346 cfg80211_sched_scan_results(hw->wiphy, 0);
1347 }
1348 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1349
ieee80211_sched_scan_end(struct ieee80211_local * local)1350 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1351 {
1352 mutex_lock(&local->mtx);
1353
1354 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1355 mutex_unlock(&local->mtx);
1356 return;
1357 }
1358
1359 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1360
1361 /* If sched scan was aborted by the driver. */
1362 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1363
1364 mutex_unlock(&local->mtx);
1365
1366 cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1367 }
1368
ieee80211_sched_scan_stopped_work(struct work_struct * work)1369 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1370 {
1371 struct ieee80211_local *local =
1372 container_of(work, struct ieee80211_local,
1373 sched_scan_stopped_work);
1374
1375 ieee80211_sched_scan_end(local);
1376 }
1377
ieee80211_sched_scan_stopped(struct ieee80211_hw * hw)1378 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1379 {
1380 struct ieee80211_local *local = hw_to_local(hw);
1381
1382 trace_api_sched_scan_stopped(local);
1383
1384 /*
1385 * this shouldn't really happen, so for simplicity
1386 * simply ignore it, and let mac80211 reconfigure
1387 * the sched scan later on.
1388 */
1389 if (local->in_reconfig)
1390 return;
1391
1392 schedule_work(&local->sched_scan_stopped_work);
1393 }
1394 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
1395