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1/*
2 * Scanning implementation
3 *
4 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
5 * Copyright 2004, Instant802 Networks, Inc.
6 * Copyright 2005, Devicescape Software, Inc.
7 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
8 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
9 * Copyright 2013-2015 Intel Mobile Communications GmbH
10 * Copyright 2016-2017 Intel Deutschland GmbH
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
15 */
16
17#include <linux/if_arp.h>
18#include <linux/etherdevice.h>
19#include <linux/rtnetlink.h>
20#include <net/sch_generic.h>
21#include <linux/slab.h>
22#include <linux/export.h>
23#include <net/mac80211.h>
24
25#include "ieee80211_i.h"
26#include "driver-ops.h"
27#include "mesh.h"
28
29#define IEEE80211_PROBE_DELAY (HZ / 33)
30#define IEEE80211_CHANNEL_TIME (HZ / 33)
31#define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
32
33void ieee80211_rx_bss_put(struct ieee80211_local *local,
34 struct ieee80211_bss *bss)
35{
36 if (!bss)
37 return;
38 cfg80211_put_bss(local->hw.wiphy,
39 container_of((void *)bss, struct cfg80211_bss, priv));
40}
41
42static bool is_uapsd_supported(struct ieee802_11_elems *elems)
43{
44 u8 qos_info;
45
46 if (elems->wmm_info && elems->wmm_info_len == 7
47 && elems->wmm_info[5] == 1)
48 qos_info = elems->wmm_info[6];
49 else if (elems->wmm_param && elems->wmm_param_len == 24
50 && elems->wmm_param[5] == 1)
51 qos_info = elems->wmm_param[6];
52 else
53 /* no valid wmm information or parameter element found */
54 return false;
55
56 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
57}
58
59struct ieee80211_bss *
60ieee80211_bss_info_update(struct ieee80211_local *local,
61 struct ieee80211_rx_status *rx_status,
62 struct ieee80211_mgmt *mgmt, size_t len,
63 struct ieee802_11_elems *elems,
64 struct ieee80211_channel *channel)
65{
66 bool beacon = ieee80211_is_beacon(mgmt->frame_control);
67 struct cfg80211_bss *cbss;
68 struct ieee80211_bss *bss;
69 int clen, srlen;
70 struct cfg80211_inform_bss bss_meta = {
71 .boottime_ns = rx_status->boottime_ns,
72 };
73 bool signal_valid;
74 struct ieee80211_sub_if_data *scan_sdata;
75
76 if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
77 bss_meta.signal = 0; /* invalid signal indication */
78 else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
79 bss_meta.signal = rx_status->signal * 100;
80 else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
81 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
82
83 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
84 if (rx_status->bw == RATE_INFO_BW_5)
85 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
86 else if (rx_status->bw == RATE_INFO_BW_10)
87 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
88
89 bss_meta.chan = channel;
90
91 rcu_read_lock();
92 scan_sdata = rcu_dereference(local->scan_sdata);
93 if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
94 scan_sdata->vif.bss_conf.assoc &&
95 ieee80211_have_rx_timestamp(rx_status)) {
96 bss_meta.parent_tsf =
97 ieee80211_calculate_rx_timestamp(local, rx_status,
98 len + FCS_LEN, 24);
99 ether_addr_copy(bss_meta.parent_bssid,
100 scan_sdata->vif.bss_conf.bssid);
101 }
102 rcu_read_unlock();
103
104 cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
105 mgmt, len, GFP_ATOMIC);
106 if (!cbss)
107 return NULL;
108 /* In case the signal is invalid update the status */
109 signal_valid = abs(channel->center_freq - cbss->channel->center_freq)
110 <= local->hw.wiphy->max_adj_channel_rssi_comp;
111 if (!signal_valid)
112 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
113
114 bss = (void *)cbss->priv;
115
116 if (beacon)
117 bss->device_ts_beacon = rx_status->device_timestamp;
118 else
119 bss->device_ts_presp = rx_status->device_timestamp;
120
121 if (elems->parse_error) {
122 if (beacon)
123 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
124 else
125 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
126 } else {
127 if (beacon)
128 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
129 else
130 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
131 }
132
133 /* save the ERP value so that it is available at association time */
134 if (elems->erp_info && (!elems->parse_error ||
135 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
136 bss->erp_value = elems->erp_info[0];
137 bss->has_erp_value = true;
138 if (!elems->parse_error)
139 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
140 }
141
142 /* replace old supported rates if we get new values */
143 if (!elems->parse_error ||
144 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
145 srlen = 0;
146 if (elems->supp_rates) {
147 clen = IEEE80211_MAX_SUPP_RATES;
148 if (clen > elems->supp_rates_len)
149 clen = elems->supp_rates_len;
150 memcpy(bss->supp_rates, elems->supp_rates, clen);
151 srlen += clen;
152 }
153 if (elems->ext_supp_rates) {
154 clen = IEEE80211_MAX_SUPP_RATES - srlen;
155 if (clen > elems->ext_supp_rates_len)
156 clen = elems->ext_supp_rates_len;
157 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
158 clen);
159 srlen += clen;
160 }
161 if (srlen) {
162 bss->supp_rates_len = srlen;
163 if (!elems->parse_error)
164 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
165 }
166 }
167
168 if (!elems->parse_error ||
169 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
170 bss->wmm_used = elems->wmm_param || elems->wmm_info;
171 bss->uapsd_supported = is_uapsd_supported(elems);
172 if (!elems->parse_error)
173 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
174 }
175
176 if (beacon) {
177 struct ieee80211_supported_band *sband =
178 local->hw.wiphy->bands[rx_status->band];
179 if (!(rx_status->encoding == RX_ENC_HT) &&
180 !(rx_status->encoding == RX_ENC_VHT))
181 bss->beacon_rate =
182 &sband->bitrates[rx_status->rate_idx];
183 }
184
185 return bss;
186}
187
188static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
189 u32 scan_flags, const u8 *da)
190{
191 if (!sdata)
192 return false;
193 /* accept broadcast for OCE */
194 if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
195 is_broadcast_ether_addr(da))
196 return true;
197 if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
198 return true;
199 return ether_addr_equal(da, sdata->vif.addr);
200}
201
202void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
203{
204 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
205 struct ieee80211_sub_if_data *sdata1, *sdata2;
206 struct ieee80211_mgmt *mgmt = (void *)skb->data;
207 struct ieee80211_bss *bss;
208 u8 *elements;
209 struct ieee80211_channel *channel;
210 size_t baselen;
211 struct ieee802_11_elems elems;
212
213 if (skb->len < 24 ||
214 (!ieee80211_is_probe_resp(mgmt->frame_control) &&
215 !ieee80211_is_beacon(mgmt->frame_control)))
216 return;
217
218 sdata1 = rcu_dereference(local->scan_sdata);
219 sdata2 = rcu_dereference(local->sched_scan_sdata);
220
221 if (likely(!sdata1 && !sdata2))
222 return;
223
224 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
225 struct cfg80211_scan_request *scan_req;
226 struct cfg80211_sched_scan_request *sched_scan_req;
227 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
228
229 scan_req = rcu_dereference(local->scan_req);
230 sched_scan_req = rcu_dereference(local->sched_scan_req);
231
232 if (scan_req)
233 scan_req_flags = scan_req->flags;
234
235 if (sched_scan_req)
236 sched_scan_req_flags = sched_scan_req->flags;
237
238 /* ignore ProbeResp to foreign address or non-bcast (OCE)
239 * unless scanning with randomised address
240 */
241 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
242 mgmt->da) &&
243 !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
244 mgmt->da))
245 return;
246
247 elements = mgmt->u.probe_resp.variable;
248 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
249 } else {
250 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
251 elements = mgmt->u.beacon.variable;
252 }
253
254 if (baselen > skb->len)
255 return;
256
257 ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems);
258
259 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
260
261 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
262 return;
263
264 bss = ieee80211_bss_info_update(local, rx_status,
265 mgmt, skb->len, &elems,
266 channel);
267 if (bss)
268 ieee80211_rx_bss_put(local, bss);
269}
270
271static void
272ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
273 enum nl80211_bss_scan_width scan_width)
274{
275 memset(chandef, 0, sizeof(*chandef));
276 switch (scan_width) {
277 case NL80211_BSS_CHAN_WIDTH_5:
278 chandef->width = NL80211_CHAN_WIDTH_5;
279 break;
280 case NL80211_BSS_CHAN_WIDTH_10:
281 chandef->width = NL80211_CHAN_WIDTH_10;
282 break;
283 default:
284 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
285 break;
286 }
287}
288
289/* return false if no more work */
290static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
291{
292 struct cfg80211_scan_request *req;
293 struct cfg80211_chan_def chandef;
294 u8 bands_used = 0;
295 int i, ielen, n_chans;
296
297 req = rcu_dereference_protected(local->scan_req,
298 lockdep_is_held(&local->mtx));
299
300 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
301 return false;
302
303 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
304 for (i = 0; i < req->n_channels; i++) {
305 local->hw_scan_req->req.channels[i] = req->channels[i];
306 bands_used |= BIT(req->channels[i]->band);
307 }
308
309 n_chans = req->n_channels;
310 } else {
311 do {
312 if (local->hw_scan_band == NUM_NL80211_BANDS)
313 return false;
314
315 n_chans = 0;
316
317 for (i = 0; i < req->n_channels; i++) {
318 if (req->channels[i]->band !=
319 local->hw_scan_band)
320 continue;
321 local->hw_scan_req->req.channels[n_chans] =
322 req->channels[i];
323 n_chans++;
324 bands_used |= BIT(req->channels[i]->band);
325 }
326
327 local->hw_scan_band++;
328 } while (!n_chans);
329 }
330
331 local->hw_scan_req->req.n_channels = n_chans;
332 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
333
334 ielen = ieee80211_build_preq_ies(local,
335 (u8 *)local->hw_scan_req->req.ie,
336 local->hw_scan_ies_bufsize,
337 &local->hw_scan_req->ies,
338 req->ie, req->ie_len,
339 bands_used, req->rates, &chandef);
340 local->hw_scan_req->req.ie_len = ielen;
341 local->hw_scan_req->req.no_cck = req->no_cck;
342 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
343 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
344 req->mac_addr_mask);
345 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
346
347 return true;
348}
349
350static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
351{
352 struct ieee80211_local *local = hw_to_local(hw);
353 bool hw_scan = local->ops->hw_scan;
354 bool was_scanning = local->scanning;
355 struct cfg80211_scan_request *scan_req;
356 struct ieee80211_sub_if_data *scan_sdata;
357 struct ieee80211_sub_if_data *sdata;
358
359 lockdep_assert_held(&local->mtx);
360
361 /*
362 * It's ok to abort a not-yet-running scan (that
363 * we have one at all will be verified by checking
364 * local->scan_req next), but not to complete it
365 * successfully.
366 */
367 if (WARN_ON(!local->scanning && !aborted))
368 aborted = true;
369
370 if (WARN_ON(!local->scan_req))
371 return;
372
373 if (hw_scan && !aborted &&
374 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
375 ieee80211_prep_hw_scan(local)) {
376 int rc;
377
378 rc = drv_hw_scan(local,
379 rcu_dereference_protected(local->scan_sdata,
380 lockdep_is_held(&local->mtx)),
381 local->hw_scan_req);
382
383 if (rc == 0)
384 return;
385
386 /* HW scan failed and is going to be reported as aborted,
387 * so clear old scan info.
388 */
389 memset(&local->scan_info, 0, sizeof(local->scan_info));
390 aborted = true;
391 }
392
393 kfree(local->hw_scan_req);
394 local->hw_scan_req = NULL;
395
396 scan_req = rcu_dereference_protected(local->scan_req,
397 lockdep_is_held(&local->mtx));
398
399 if (scan_req != local->int_scan_req) {
400 local->scan_info.aborted = aborted;
401 cfg80211_scan_done(scan_req, &local->scan_info);
402 }
403 RCU_INIT_POINTER(local->scan_req, NULL);
404
405 scan_sdata = rcu_dereference_protected(local->scan_sdata,
406 lockdep_is_held(&local->mtx));
407 RCU_INIT_POINTER(local->scan_sdata, NULL);
408
409 local->scanning = 0;
410 local->scan_chandef.chan = NULL;
411
412 /* Set power back to normal operating levels. */
413 ieee80211_hw_config(local, 0);
414
415 if (!hw_scan) {
416 ieee80211_configure_filter(local);
417 drv_sw_scan_complete(local, scan_sdata);
418 ieee80211_offchannel_return(local);
419 }
420
421 ieee80211_recalc_idle(local);
422
423 ieee80211_mlme_notify_scan_completed(local);
424 ieee80211_ibss_notify_scan_completed(local);
425
426 /* Requeue all the work that might have been ignored while
427 * the scan was in progress; if there was none this will
428 * just be a no-op for the particular interface.
429 */
430 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
431 if (ieee80211_sdata_running(sdata))
432 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
433 }
434
435 if (was_scanning)
436 ieee80211_start_next_roc(local);
437}
438
439void ieee80211_scan_completed(struct ieee80211_hw *hw,
440 struct cfg80211_scan_info *info)
441{
442 struct ieee80211_local *local = hw_to_local(hw);
443
444 trace_api_scan_completed(local, info->aborted);
445
446 set_bit(SCAN_COMPLETED, &local->scanning);
447 if (info->aborted)
448 set_bit(SCAN_ABORTED, &local->scanning);
449
450 memcpy(&local->scan_info, info, sizeof(*info));
451
452 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
453}
454EXPORT_SYMBOL(ieee80211_scan_completed);
455
456static int ieee80211_start_sw_scan(struct ieee80211_local *local,
457 struct ieee80211_sub_if_data *sdata)
458{
459 /* Software scan is not supported in multi-channel cases */
460 if (local->use_chanctx)
461 return -EOPNOTSUPP;
462
463 /*
464 * Hardware/driver doesn't support hw_scan, so use software
465 * scanning instead. First send a nullfunc frame with power save
466 * bit on so that AP will buffer the frames for us while we are not
467 * listening, then send probe requests to each channel and wait for
468 * the responses. After all channels are scanned, tune back to the
469 * original channel and send a nullfunc frame with power save bit
470 * off to trigger the AP to send us all the buffered frames.
471 *
472 * Note that while local->sw_scanning is true everything else but
473 * nullfunc frames and probe requests will be dropped in
474 * ieee80211_tx_h_check_assoc().
475 */
476 drv_sw_scan_start(local, sdata, local->scan_addr);
477
478 local->leave_oper_channel_time = jiffies;
479 local->next_scan_state = SCAN_DECISION;
480 local->scan_channel_idx = 0;
481
482 ieee80211_offchannel_stop_vifs(local);
483
484 /* ensure nullfunc is transmitted before leaving operating channel */
485 ieee80211_flush_queues(local, NULL, false);
486
487 ieee80211_configure_filter(local);
488
489 /* We need to set power level at maximum rate for scanning. */
490 ieee80211_hw_config(local, 0);
491
492 ieee80211_queue_delayed_work(&local->hw,
493 &local->scan_work, 0);
494
495 return 0;
496}
497
498static bool ieee80211_can_scan(struct ieee80211_local *local,
499 struct ieee80211_sub_if_data *sdata)
500{
501 if (ieee80211_is_radar_required(local))
502 return false;
503
504 if (!list_empty(&local->roc_list))
505 return false;
506
507 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
508 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
509 return false;
510
511 return true;
512}
513
514void ieee80211_run_deferred_scan(struct ieee80211_local *local)
515{
516 lockdep_assert_held(&local->mtx);
517
518 if (!local->scan_req || local->scanning)
519 return;
520
521 if (!ieee80211_can_scan(local,
522 rcu_dereference_protected(
523 local->scan_sdata,
524 lockdep_is_held(&local->mtx))))
525 return;
526
527 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
528 round_jiffies_relative(0));
529}
530
531static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
532 unsigned long *next_delay)
533{
534 int i;
535 struct ieee80211_sub_if_data *sdata;
536 struct cfg80211_scan_request *scan_req;
537 enum nl80211_band band = local->hw.conf.chandef.chan->band;
538 u32 tx_flags;
539
540 scan_req = rcu_dereference_protected(local->scan_req,
541 lockdep_is_held(&local->mtx));
542
543 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
544 if (scan_req->no_cck)
545 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
546
547 sdata = rcu_dereference_protected(local->scan_sdata,
548 lockdep_is_held(&local->mtx));
549
550 for (i = 0; i < scan_req->n_ssids; i++)
551 ieee80211_send_probe_req(
552 sdata, local->scan_addr, scan_req->bssid,
553 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
554 scan_req->ie, scan_req->ie_len,
555 scan_req->rates[band], false,
556 tx_flags, local->hw.conf.chandef.chan, true);
557
558 /*
559 * After sending probe requests, wait for probe responses
560 * on the channel.
561 */
562 *next_delay = IEEE80211_CHANNEL_TIME;
563 local->next_scan_state = SCAN_DECISION;
564}
565
566static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
567 struct cfg80211_scan_request *req)
568{
569 struct ieee80211_local *local = sdata->local;
570 int rc;
571
572 lockdep_assert_held(&local->mtx);
573
574 if (local->scan_req || ieee80211_is_radar_required(local))
575 return -EBUSY;
576
577 if (!ieee80211_can_scan(local, sdata)) {
578 /* wait for the work to finish/time out */
579 rcu_assign_pointer(local->scan_req, req);
580 rcu_assign_pointer(local->scan_sdata, sdata);
581 return 0;
582 }
583
584 if (local->ops->hw_scan) {
585 u8 *ies;
586
587 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
588
589 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
590 int i, n_bands = 0;
591 u8 bands_counted = 0;
592
593 for (i = 0; i < req->n_channels; i++) {
594 if (bands_counted & BIT(req->channels[i]->band))
595 continue;
596 bands_counted |= BIT(req->channels[i]->band);
597 n_bands++;
598 }
599
600 local->hw_scan_ies_bufsize *= n_bands;
601 }
602
603 local->hw_scan_req = kmalloc(
604 sizeof(*local->hw_scan_req) +
605 req->n_channels * sizeof(req->channels[0]) +
606 local->hw_scan_ies_bufsize, GFP_KERNEL);
607 if (!local->hw_scan_req)
608 return -ENOMEM;
609
610 local->hw_scan_req->req.ssids = req->ssids;
611 local->hw_scan_req->req.n_ssids = req->n_ssids;
612 ies = (u8 *)local->hw_scan_req +
613 sizeof(*local->hw_scan_req) +
614 req->n_channels * sizeof(req->channels[0]);
615 local->hw_scan_req->req.ie = ies;
616 local->hw_scan_req->req.flags = req->flags;
617 eth_broadcast_addr(local->hw_scan_req->req.bssid);
618 local->hw_scan_req->req.duration = req->duration;
619 local->hw_scan_req->req.duration_mandatory =
620 req->duration_mandatory;
621
622 local->hw_scan_band = 0;
623
624 /*
625 * After allocating local->hw_scan_req, we must
626 * go through until ieee80211_prep_hw_scan(), so
627 * anything that might be changed here and leave
628 * this function early must not go after this
629 * allocation.
630 */
631 }
632
633 rcu_assign_pointer(local->scan_req, req);
634 rcu_assign_pointer(local->scan_sdata, sdata);
635
636 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
637 get_random_mask_addr(local->scan_addr,
638 req->mac_addr,
639 req->mac_addr_mask);
640 else
641 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
642
643 if (local->ops->hw_scan) {
644 __set_bit(SCAN_HW_SCANNING, &local->scanning);
645 } else if ((req->n_channels == 1) &&
646 (req->channels[0] == local->_oper_chandef.chan)) {
647 /*
648 * If we are scanning only on the operating channel
649 * then we do not need to stop normal activities
650 */
651 unsigned long next_delay;
652
653 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
654
655 ieee80211_recalc_idle(local);
656
657 /* Notify driver scan is starting, keep order of operations
658 * same as normal software scan, in case that matters. */
659 drv_sw_scan_start(local, sdata, local->scan_addr);
660
661 ieee80211_configure_filter(local); /* accept probe-responses */
662
663 /* We need to ensure power level is at max for scanning. */
664 ieee80211_hw_config(local, 0);
665
666 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
667 IEEE80211_CHAN_RADAR)) ||
668 !req->n_ssids) {
669 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
670 } else {
671 ieee80211_scan_state_send_probe(local, &next_delay);
672 next_delay = IEEE80211_CHANNEL_TIME;
673 }
674
675 /* Now, just wait a bit and we are all done! */
676 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
677 next_delay);
678 return 0;
679 } else {
680 /* Do normal software scan */
681 __set_bit(SCAN_SW_SCANNING, &local->scanning);
682 }
683
684 ieee80211_recalc_idle(local);
685
686 if (local->ops->hw_scan) {
687 WARN_ON(!ieee80211_prep_hw_scan(local));
688 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
689 } else {
690 rc = ieee80211_start_sw_scan(local, sdata);
691 }
692
693 if (rc) {
694 kfree(local->hw_scan_req);
695 local->hw_scan_req = NULL;
696 local->scanning = 0;
697
698 ieee80211_recalc_idle(local);
699
700 local->scan_req = NULL;
701 RCU_INIT_POINTER(local->scan_sdata, NULL);
702 }
703
704 return rc;
705}
706
707static unsigned long
708ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
709{
710 /*
711 * TODO: channel switching also consumes quite some time,
712 * add that delay as well to get a better estimation
713 */
714 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
715 return IEEE80211_PASSIVE_CHANNEL_TIME;
716 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
717}
718
719static void ieee80211_scan_state_decision(struct ieee80211_local *local,
720 unsigned long *next_delay)
721{
722 bool associated = false;
723 bool tx_empty = true;
724 bool bad_latency;
725 struct ieee80211_sub_if_data *sdata;
726 struct ieee80211_channel *next_chan;
727 enum mac80211_scan_state next_scan_state;
728 struct cfg80211_scan_request *scan_req;
729
730 /*
731 * check if at least one STA interface is associated,
732 * check if at least one STA interface has pending tx frames
733 * and grab the lowest used beacon interval
734 */
735 mutex_lock(&local->iflist_mtx);
736 list_for_each_entry(sdata, &local->interfaces, list) {
737 if (!ieee80211_sdata_running(sdata))
738 continue;
739
740 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
741 if (sdata->u.mgd.associated) {
742 associated = true;
743
744 if (!qdisc_all_tx_empty(sdata->dev)) {
745 tx_empty = false;
746 break;
747 }
748 }
749 }
750 }
751 mutex_unlock(&local->iflist_mtx);
752
753 scan_req = rcu_dereference_protected(local->scan_req,
754 lockdep_is_held(&local->mtx));
755
756 next_chan = scan_req->channels[local->scan_channel_idx];
757
758 /*
759 * we're currently scanning a different channel, let's
760 * see if we can scan another channel without interfering
761 * with the current traffic situation.
762 *
763 * Keep good latency, do not stay off-channel more than 125 ms.
764 */
765
766 bad_latency = time_after(jiffies +
767 ieee80211_scan_get_channel_time(next_chan),
768 local->leave_oper_channel_time + HZ / 8);
769
770 if (associated && !tx_empty) {
771 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
772 next_scan_state = SCAN_ABORT;
773 else
774 next_scan_state = SCAN_SUSPEND;
775 } else if (associated && bad_latency) {
776 next_scan_state = SCAN_SUSPEND;
777 } else {
778 next_scan_state = SCAN_SET_CHANNEL;
779 }
780
781 local->next_scan_state = next_scan_state;
782
783 *next_delay = 0;
784}
785
786static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
787 unsigned long *next_delay)
788{
789 int skip;
790 struct ieee80211_channel *chan;
791 enum nl80211_bss_scan_width oper_scan_width;
792 struct cfg80211_scan_request *scan_req;
793
794 scan_req = rcu_dereference_protected(local->scan_req,
795 lockdep_is_held(&local->mtx));
796
797 skip = 0;
798 chan = scan_req->channels[local->scan_channel_idx];
799
800 local->scan_chandef.chan = chan;
801 local->scan_chandef.center_freq1 = chan->center_freq;
802 local->scan_chandef.center_freq2 = 0;
803 switch (scan_req->scan_width) {
804 case NL80211_BSS_CHAN_WIDTH_5:
805 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
806 break;
807 case NL80211_BSS_CHAN_WIDTH_10:
808 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
809 break;
810 case NL80211_BSS_CHAN_WIDTH_20:
811 /* If scanning on oper channel, use whatever channel-type
812 * is currently in use.
813 */
814 oper_scan_width = cfg80211_chandef_to_scan_width(
815 &local->_oper_chandef);
816 if (chan == local->_oper_chandef.chan &&
817 oper_scan_width == scan_req->scan_width)
818 local->scan_chandef = local->_oper_chandef;
819 else
820 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
821 break;
822 }
823
824 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
825 skip = 1;
826
827 /* advance state machine to next channel/band */
828 local->scan_channel_idx++;
829
830 if (skip) {
831 /* if we skip this channel return to the decision state */
832 local->next_scan_state = SCAN_DECISION;
833 return;
834 }
835
836 /*
837 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
838 * (which unfortunately doesn't say _why_ step a) is done,
839 * but it waits for the probe delay or until a frame is
840 * received - and the received frame would update the NAV).
841 * For now, we do not support waiting until a frame is
842 * received.
843 *
844 * In any case, it is not necessary for a passive scan.
845 */
846 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
847 !scan_req->n_ssids) {
848 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
849 local->next_scan_state = SCAN_DECISION;
850 return;
851 }
852
853 /* active scan, send probes */
854 *next_delay = IEEE80211_PROBE_DELAY;
855 local->next_scan_state = SCAN_SEND_PROBE;
856}
857
858static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
859 unsigned long *next_delay)
860{
861 /* switch back to the operating channel */
862 local->scan_chandef.chan = NULL;
863 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
864
865 /* disable PS */
866 ieee80211_offchannel_return(local);
867
868 *next_delay = HZ / 5;
869 /* afterwards, resume scan & go to next channel */
870 local->next_scan_state = SCAN_RESUME;
871}
872
873static void ieee80211_scan_state_resume(struct ieee80211_local *local,
874 unsigned long *next_delay)
875{
876 ieee80211_offchannel_stop_vifs(local);
877
878 if (local->ops->flush) {
879 ieee80211_flush_queues(local, NULL, false);
880 *next_delay = 0;
881 } else
882 *next_delay = HZ / 10;
883
884 /* remember when we left the operating channel */
885 local->leave_oper_channel_time = jiffies;
886
887 /* advance to the next channel to be scanned */
888 local->next_scan_state = SCAN_SET_CHANNEL;
889}
890
891void ieee80211_scan_work(struct work_struct *work)
892{
893 struct ieee80211_local *local =
894 container_of(work, struct ieee80211_local, scan_work.work);
895 struct ieee80211_sub_if_data *sdata;
896 struct cfg80211_scan_request *scan_req;
897 unsigned long next_delay = 0;
898 bool aborted;
899
900 mutex_lock(&local->mtx);
901
902 if (!ieee80211_can_run_worker(local)) {
903 aborted = true;
904 goto out_complete;
905 }
906
907 sdata = rcu_dereference_protected(local->scan_sdata,
908 lockdep_is_held(&local->mtx));
909 scan_req = rcu_dereference_protected(local->scan_req,
910 lockdep_is_held(&local->mtx));
911
912 /* When scanning on-channel, the first-callback means completed. */
913 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
914 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
915 goto out_complete;
916 }
917
918 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
919 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
920 goto out_complete;
921 }
922
923 if (!sdata || !scan_req)
924 goto out;
925
926 if (!local->scanning) {
927 int rc;
928
929 RCU_INIT_POINTER(local->scan_req, NULL);
930 RCU_INIT_POINTER(local->scan_sdata, NULL);
931
932 rc = __ieee80211_start_scan(sdata, scan_req);
933 if (rc) {
934 /* need to complete scan in cfg80211 */
935 rcu_assign_pointer(local->scan_req, scan_req);
936 aborted = true;
937 goto out_complete;
938 } else
939 goto out;
940 }
941
942 /*
943 * as long as no delay is required advance immediately
944 * without scheduling a new work
945 */
946 do {
947 if (!ieee80211_sdata_running(sdata)) {
948 aborted = true;
949 goto out_complete;
950 }
951
952 switch (local->next_scan_state) {
953 case SCAN_DECISION:
954 /* if no more bands/channels left, complete scan */
955 if (local->scan_channel_idx >= scan_req->n_channels) {
956 aborted = false;
957 goto out_complete;
958 }
959 ieee80211_scan_state_decision(local, &next_delay);
960 break;
961 case SCAN_SET_CHANNEL:
962 ieee80211_scan_state_set_channel(local, &next_delay);
963 break;
964 case SCAN_SEND_PROBE:
965 ieee80211_scan_state_send_probe(local, &next_delay);
966 break;
967 case SCAN_SUSPEND:
968 ieee80211_scan_state_suspend(local, &next_delay);
969 break;
970 case SCAN_RESUME:
971 ieee80211_scan_state_resume(local, &next_delay);
972 break;
973 case SCAN_ABORT:
974 aborted = true;
975 goto out_complete;
976 }
977 } while (next_delay == 0);
978
979 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
980 goto out;
981
982out_complete:
983 __ieee80211_scan_completed(&local->hw, aborted);
984out:
985 mutex_unlock(&local->mtx);
986}
987
988int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
989 struct cfg80211_scan_request *req)
990{
991 int res;
992
993 mutex_lock(&sdata->local->mtx);
994 res = __ieee80211_start_scan(sdata, req);
995 mutex_unlock(&sdata->local->mtx);
996
997 return res;
998}
999
1000int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1001 const u8 *ssid, u8 ssid_len,
1002 struct ieee80211_channel **channels,
1003 unsigned int n_channels,
1004 enum nl80211_bss_scan_width scan_width)
1005{
1006 struct ieee80211_local *local = sdata->local;
1007 int ret = -EBUSY, i, n_ch = 0;
1008 enum nl80211_band band;
1009
1010 mutex_lock(&local->mtx);
1011
1012 /* busy scanning */
1013 if (local->scan_req)
1014 goto unlock;
1015
1016 /* fill internal scan request */
1017 if (!channels) {
1018 int max_n;
1019
1020 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1021 if (!local->hw.wiphy->bands[band])
1022 continue;
1023
1024 max_n = local->hw.wiphy->bands[band]->n_channels;
1025 for (i = 0; i < max_n; i++) {
1026 struct ieee80211_channel *tmp_ch =
1027 &local->hw.wiphy->bands[band]->channels[i];
1028
1029 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1030 IEEE80211_CHAN_DISABLED))
1031 continue;
1032
1033 local->int_scan_req->channels[n_ch] = tmp_ch;
1034 n_ch++;
1035 }
1036 }
1037
1038 if (WARN_ON_ONCE(n_ch == 0))
1039 goto unlock;
1040
1041 local->int_scan_req->n_channels = n_ch;
1042 } else {
1043 for (i = 0; i < n_channels; i++) {
1044 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1045 IEEE80211_CHAN_DISABLED))
1046 continue;
1047
1048 local->int_scan_req->channels[n_ch] = channels[i];
1049 n_ch++;
1050 }
1051
1052 if (WARN_ON_ONCE(n_ch == 0))
1053 goto unlock;
1054
1055 local->int_scan_req->n_channels = n_ch;
1056 }
1057
1058 local->int_scan_req->ssids = &local->scan_ssid;
1059 local->int_scan_req->n_ssids = 1;
1060 local->int_scan_req->scan_width = scan_width;
1061 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1062 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1063
1064 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1065 unlock:
1066 mutex_unlock(&local->mtx);
1067 return ret;
1068}
1069
1070/*
1071 * Only call this function when a scan can't be queued -- under RTNL.
1072 */
1073void ieee80211_scan_cancel(struct ieee80211_local *local)
1074{
1075 /*
1076 * We are canceling software scan, or deferred scan that was not
1077 * yet really started (see __ieee80211_start_scan ).
1078 *
1079 * Regarding hardware scan:
1080 * - we can not call __ieee80211_scan_completed() as when
1081 * SCAN_HW_SCANNING bit is set this function change
1082 * local->hw_scan_req to operate on 5G band, what race with
1083 * driver which can use local->hw_scan_req
1084 *
1085 * - we can not cancel scan_work since driver can schedule it
1086 * by ieee80211_scan_completed(..., true) to finish scan
1087 *
1088 * Hence we only call the cancel_hw_scan() callback, but the low-level
1089 * driver is still responsible for calling ieee80211_scan_completed()
1090 * after the scan was completed/aborted.
1091 */
1092
1093 mutex_lock(&local->mtx);
1094 if (!local->scan_req)
1095 goto out;
1096
1097 /*
1098 * We have a scan running and the driver already reported completion,
1099 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1100 * cancelled.
1101 */
1102 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1103 test_bit(SCAN_COMPLETED, &local->scanning)) {
1104 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1105 goto out;
1106 }
1107
1108 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1109 /*
1110 * Make sure that __ieee80211_scan_completed doesn't trigger a
1111 * scan on another band.
1112 */
1113 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1114 if (local->ops->cancel_hw_scan)
1115 drv_cancel_hw_scan(local,
1116 rcu_dereference_protected(local->scan_sdata,
1117 lockdep_is_held(&local->mtx)));
1118 goto out;
1119 }
1120
1121 /*
1122 * If the work is currently running, it must be blocked on
1123 * the mutex, but we'll set scan_sdata = NULL and it'll
1124 * simply exit once it acquires the mutex.
1125 */
1126 cancel_delayed_work(&local->scan_work);
1127 /* and clean up */
1128 memset(&local->scan_info, 0, sizeof(local->scan_info));
1129 __ieee80211_scan_completed(&local->hw, true);
1130out:
1131 mutex_unlock(&local->mtx);
1132}
1133
1134int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1135 struct cfg80211_sched_scan_request *req)
1136{
1137 struct ieee80211_local *local = sdata->local;
1138 struct ieee80211_scan_ies sched_scan_ies = {};
1139 struct cfg80211_chan_def chandef;
1140 int ret, i, iebufsz, num_bands = 0;
1141 u32 rate_masks[NUM_NL80211_BANDS] = {};
1142 u8 bands_used = 0;
1143 u8 *ie;
1144
1145 iebufsz = local->scan_ies_len + req->ie_len;
1146
1147 lockdep_assert_held(&local->mtx);
1148
1149 if (!local->ops->sched_scan_start)
1150 return -ENOTSUPP;
1151
1152 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1153 if (local->hw.wiphy->bands[i]) {
1154 bands_used |= BIT(i);
1155 rate_masks[i] = (u32) -1;
1156 num_bands++;
1157 }
1158 }
1159
1160 ie = kzalloc(num_bands * iebufsz, GFP_KERNEL);
1161 if (!ie) {
1162 ret = -ENOMEM;
1163 goto out;
1164 }
1165
1166 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1167
1168 ieee80211_build_preq_ies(local, ie, num_bands * iebufsz,
1169 &sched_scan_ies, req->ie,
1170 req->ie_len, bands_used, rate_masks, &chandef);
1171
1172 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1173 if (ret == 0) {
1174 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1175 rcu_assign_pointer(local->sched_scan_req, req);
1176 }
1177
1178 kfree(ie);
1179
1180out:
1181 if (ret) {
1182 /* Clean in case of failure after HW restart or upon resume. */
1183 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1184 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1185 }
1186
1187 return ret;
1188}
1189
1190int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1191 struct cfg80211_sched_scan_request *req)
1192{
1193 struct ieee80211_local *local = sdata->local;
1194 int ret;
1195
1196 mutex_lock(&local->mtx);
1197
1198 if (rcu_access_pointer(local->sched_scan_sdata)) {
1199 mutex_unlock(&local->mtx);
1200 return -EBUSY;
1201 }
1202
1203 ret = __ieee80211_request_sched_scan_start(sdata, req);
1204
1205 mutex_unlock(&local->mtx);
1206 return ret;
1207}
1208
1209int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1210{
1211 struct ieee80211_sub_if_data *sched_scan_sdata;
1212 int ret = -ENOENT;
1213
1214 mutex_lock(&local->mtx);
1215
1216 if (!local->ops->sched_scan_stop) {
1217 ret = -ENOTSUPP;
1218 goto out;
1219 }
1220
1221 /* We don't want to restart sched scan anymore. */
1222 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1223
1224 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1225 lockdep_is_held(&local->mtx));
1226 if (sched_scan_sdata) {
1227 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1228 if (!ret)
1229 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1230 }
1231out:
1232 mutex_unlock(&local->mtx);
1233
1234 return ret;
1235}
1236
1237void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1238{
1239 struct ieee80211_local *local = hw_to_local(hw);
1240
1241 trace_api_sched_scan_results(local);
1242
1243 cfg80211_sched_scan_results(hw->wiphy, 0);
1244}
1245EXPORT_SYMBOL(ieee80211_sched_scan_results);
1246
1247void ieee80211_sched_scan_end(struct ieee80211_local *local)
1248{
1249 mutex_lock(&local->mtx);
1250
1251 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1252 mutex_unlock(&local->mtx);
1253 return;
1254 }
1255
1256 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1257
1258 /* If sched scan was aborted by the driver. */
1259 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1260
1261 mutex_unlock(&local->mtx);
1262
1263 cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1264}
1265
1266void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1267{
1268 struct ieee80211_local *local =
1269 container_of(work, struct ieee80211_local,
1270 sched_scan_stopped_work);
1271
1272 ieee80211_sched_scan_end(local);
1273}
1274
1275void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1276{
1277 struct ieee80211_local *local = hw_to_local(hw);
1278
1279 trace_api_sched_scan_stopped(local);
1280
1281 /*
1282 * this shouldn't really happen, so for simplicity
1283 * simply ignore it, and let mac80211 reconfigure
1284 * the sched scan later on.
1285 */
1286 if (local->in_reconfig)
1287 return;
1288
1289 schedule_work(&local->sched_scan_stopped_work);
1290}
1291EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
1/*
2 * Scanning implementation
3 *
4 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
5 * Copyright 2004, Instant802 Networks, Inc.
6 * Copyright 2005, Devicescape Software, Inc.
7 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
8 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
9 * Copyright 2013-2015 Intel Mobile Communications GmbH
10 * Copyright 2016 Intel Deutschland GmbH
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
15 */
16
17#include <linux/if_arp.h>
18#include <linux/etherdevice.h>
19#include <linux/rtnetlink.h>
20#include <net/sch_generic.h>
21#include <linux/slab.h>
22#include <linux/export.h>
23#include <net/mac80211.h>
24
25#include "ieee80211_i.h"
26#include "driver-ops.h"
27#include "mesh.h"
28
29#define IEEE80211_PROBE_DELAY (HZ / 33)
30#define IEEE80211_CHANNEL_TIME (HZ / 33)
31#define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
32
33void ieee80211_rx_bss_put(struct ieee80211_local *local,
34 struct ieee80211_bss *bss)
35{
36 if (!bss)
37 return;
38 cfg80211_put_bss(local->hw.wiphy,
39 container_of((void *)bss, struct cfg80211_bss, priv));
40}
41
42static bool is_uapsd_supported(struct ieee802_11_elems *elems)
43{
44 u8 qos_info;
45
46 if (elems->wmm_info && elems->wmm_info_len == 7
47 && elems->wmm_info[5] == 1)
48 qos_info = elems->wmm_info[6];
49 else if (elems->wmm_param && elems->wmm_param_len == 24
50 && elems->wmm_param[5] == 1)
51 qos_info = elems->wmm_param[6];
52 else
53 /* no valid wmm information or parameter element found */
54 return false;
55
56 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
57}
58
59struct ieee80211_bss *
60ieee80211_bss_info_update(struct ieee80211_local *local,
61 struct ieee80211_rx_status *rx_status,
62 struct ieee80211_mgmt *mgmt, size_t len,
63 struct ieee802_11_elems *elems,
64 struct ieee80211_channel *channel)
65{
66 bool beacon = ieee80211_is_beacon(mgmt->frame_control);
67 struct cfg80211_bss *cbss;
68 struct ieee80211_bss *bss;
69 int clen, srlen;
70 struct cfg80211_inform_bss bss_meta = {
71 .boottime_ns = rx_status->boottime_ns,
72 };
73 bool signal_valid;
74 struct ieee80211_sub_if_data *scan_sdata;
75
76 if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
77 bss_meta.signal = rx_status->signal * 100;
78 else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
79 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
80
81 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
82 if (rx_status->flag & RX_FLAG_5MHZ)
83 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
84 if (rx_status->flag & RX_FLAG_10MHZ)
85 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
86
87 bss_meta.chan = channel;
88
89 rcu_read_lock();
90 scan_sdata = rcu_dereference(local->scan_sdata);
91 if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
92 scan_sdata->vif.bss_conf.assoc &&
93 ieee80211_have_rx_timestamp(rx_status)) {
94 bss_meta.parent_tsf =
95 ieee80211_calculate_rx_timestamp(local, rx_status,
96 len + FCS_LEN, 24);
97 ether_addr_copy(bss_meta.parent_bssid,
98 scan_sdata->vif.bss_conf.bssid);
99 }
100 rcu_read_unlock();
101
102 cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
103 mgmt, len, GFP_ATOMIC);
104 if (!cbss)
105 return NULL;
106 /* In case the signal is invalid update the status */
107 signal_valid = abs(channel->center_freq - cbss->channel->center_freq)
108 <= local->hw.wiphy->max_adj_channel_rssi_comp;
109 if (!signal_valid)
110 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
111
112 bss = (void *)cbss->priv;
113
114 if (beacon)
115 bss->device_ts_beacon = rx_status->device_timestamp;
116 else
117 bss->device_ts_presp = rx_status->device_timestamp;
118
119 if (elems->parse_error) {
120 if (beacon)
121 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
122 else
123 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
124 } else {
125 if (beacon)
126 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
127 else
128 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
129 }
130
131 /* save the ERP value so that it is available at association time */
132 if (elems->erp_info && (!elems->parse_error ||
133 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
134 bss->erp_value = elems->erp_info[0];
135 bss->has_erp_value = true;
136 if (!elems->parse_error)
137 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
138 }
139
140 /* replace old supported rates if we get new values */
141 if (!elems->parse_error ||
142 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
143 srlen = 0;
144 if (elems->supp_rates) {
145 clen = IEEE80211_MAX_SUPP_RATES;
146 if (clen > elems->supp_rates_len)
147 clen = elems->supp_rates_len;
148 memcpy(bss->supp_rates, elems->supp_rates, clen);
149 srlen += clen;
150 }
151 if (elems->ext_supp_rates) {
152 clen = IEEE80211_MAX_SUPP_RATES - srlen;
153 if (clen > elems->ext_supp_rates_len)
154 clen = elems->ext_supp_rates_len;
155 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
156 clen);
157 srlen += clen;
158 }
159 if (srlen) {
160 bss->supp_rates_len = srlen;
161 if (!elems->parse_error)
162 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
163 }
164 }
165
166 if (!elems->parse_error ||
167 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
168 bss->wmm_used = elems->wmm_param || elems->wmm_info;
169 bss->uapsd_supported = is_uapsd_supported(elems);
170 if (!elems->parse_error)
171 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
172 }
173
174 if (beacon) {
175 struct ieee80211_supported_band *sband =
176 local->hw.wiphy->bands[rx_status->band];
177 if (!(rx_status->flag & RX_FLAG_HT) &&
178 !(rx_status->flag & RX_FLAG_VHT))
179 bss->beacon_rate =
180 &sband->bitrates[rx_status->rate_idx];
181 }
182
183 return bss;
184}
185
186void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
187{
188 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
189 struct ieee80211_sub_if_data *sdata1, *sdata2;
190 struct ieee80211_mgmt *mgmt = (void *)skb->data;
191 struct ieee80211_bss *bss;
192 u8 *elements;
193 struct ieee80211_channel *channel;
194 size_t baselen;
195 struct ieee802_11_elems elems;
196
197 if (skb->len < 24 ||
198 (!ieee80211_is_probe_resp(mgmt->frame_control) &&
199 !ieee80211_is_beacon(mgmt->frame_control)))
200 return;
201
202 sdata1 = rcu_dereference(local->scan_sdata);
203 sdata2 = rcu_dereference(local->sched_scan_sdata);
204
205 if (likely(!sdata1 && !sdata2))
206 return;
207
208 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
209 struct cfg80211_scan_request *scan_req;
210 struct cfg80211_sched_scan_request *sched_scan_req;
211
212 scan_req = rcu_dereference(local->scan_req);
213 sched_scan_req = rcu_dereference(local->sched_scan_req);
214
215 /* ignore ProbeResp to foreign address unless scanning
216 * with randomised address
217 */
218 if (!(sdata1 &&
219 (ether_addr_equal(mgmt->da, sdata1->vif.addr) ||
220 scan_req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)) &&
221 !(sdata2 &&
222 (ether_addr_equal(mgmt->da, sdata2->vif.addr) ||
223 sched_scan_req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)))
224 return;
225
226 elements = mgmt->u.probe_resp.variable;
227 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
228 } else {
229 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
230 elements = mgmt->u.beacon.variable;
231 }
232
233 if (baselen > skb->len)
234 return;
235
236 ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems);
237
238 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
239
240 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
241 return;
242
243 bss = ieee80211_bss_info_update(local, rx_status,
244 mgmt, skb->len, &elems,
245 channel);
246 if (bss)
247 ieee80211_rx_bss_put(local, bss);
248}
249
250static void
251ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
252 enum nl80211_bss_scan_width scan_width)
253{
254 memset(chandef, 0, sizeof(*chandef));
255 switch (scan_width) {
256 case NL80211_BSS_CHAN_WIDTH_5:
257 chandef->width = NL80211_CHAN_WIDTH_5;
258 break;
259 case NL80211_BSS_CHAN_WIDTH_10:
260 chandef->width = NL80211_CHAN_WIDTH_10;
261 break;
262 default:
263 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
264 break;
265 }
266}
267
268/* return false if no more work */
269static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
270{
271 struct cfg80211_scan_request *req;
272 struct cfg80211_chan_def chandef;
273 u8 bands_used = 0;
274 int i, ielen, n_chans;
275
276 req = rcu_dereference_protected(local->scan_req,
277 lockdep_is_held(&local->mtx));
278
279 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
280 return false;
281
282 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
283 for (i = 0; i < req->n_channels; i++) {
284 local->hw_scan_req->req.channels[i] = req->channels[i];
285 bands_used |= BIT(req->channels[i]->band);
286 }
287
288 n_chans = req->n_channels;
289 } else {
290 do {
291 if (local->hw_scan_band == NUM_NL80211_BANDS)
292 return false;
293
294 n_chans = 0;
295
296 for (i = 0; i < req->n_channels; i++) {
297 if (req->channels[i]->band !=
298 local->hw_scan_band)
299 continue;
300 local->hw_scan_req->req.channels[n_chans] =
301 req->channels[i];
302 n_chans++;
303 bands_used |= BIT(req->channels[i]->band);
304 }
305
306 local->hw_scan_band++;
307 } while (!n_chans);
308 }
309
310 local->hw_scan_req->req.n_channels = n_chans;
311 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
312
313 ielen = ieee80211_build_preq_ies(local,
314 (u8 *)local->hw_scan_req->req.ie,
315 local->hw_scan_ies_bufsize,
316 &local->hw_scan_req->ies,
317 req->ie, req->ie_len,
318 bands_used, req->rates, &chandef);
319 local->hw_scan_req->req.ie_len = ielen;
320 local->hw_scan_req->req.no_cck = req->no_cck;
321 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
322 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
323 req->mac_addr_mask);
324 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
325
326 return true;
327}
328
329static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
330{
331 struct ieee80211_local *local = hw_to_local(hw);
332 bool hw_scan = local->ops->hw_scan;
333 bool was_scanning = local->scanning;
334 struct cfg80211_scan_request *scan_req;
335 struct ieee80211_sub_if_data *scan_sdata;
336 struct ieee80211_sub_if_data *sdata;
337
338 lockdep_assert_held(&local->mtx);
339
340 /*
341 * It's ok to abort a not-yet-running scan (that
342 * we have one at all will be verified by checking
343 * local->scan_req next), but not to complete it
344 * successfully.
345 */
346 if (WARN_ON(!local->scanning && !aborted))
347 aborted = true;
348
349 if (WARN_ON(!local->scan_req))
350 return;
351
352 if (hw_scan && !aborted &&
353 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
354 ieee80211_prep_hw_scan(local)) {
355 int rc;
356
357 rc = drv_hw_scan(local,
358 rcu_dereference_protected(local->scan_sdata,
359 lockdep_is_held(&local->mtx)),
360 local->hw_scan_req);
361
362 if (rc == 0)
363 return;
364
365 /* HW scan failed and is going to be reported as aborted,
366 * so clear old scan info.
367 */
368 memset(&local->scan_info, 0, sizeof(local->scan_info));
369 aborted = true;
370 }
371
372 kfree(local->hw_scan_req);
373 local->hw_scan_req = NULL;
374
375 scan_req = rcu_dereference_protected(local->scan_req,
376 lockdep_is_held(&local->mtx));
377
378 if (scan_req != local->int_scan_req) {
379 local->scan_info.aborted = aborted;
380 cfg80211_scan_done(scan_req, &local->scan_info);
381 }
382 RCU_INIT_POINTER(local->scan_req, NULL);
383
384 scan_sdata = rcu_dereference_protected(local->scan_sdata,
385 lockdep_is_held(&local->mtx));
386 RCU_INIT_POINTER(local->scan_sdata, NULL);
387
388 local->scanning = 0;
389 local->scan_chandef.chan = NULL;
390
391 /* Set power back to normal operating levels. */
392 ieee80211_hw_config(local, 0);
393
394 if (!hw_scan) {
395 ieee80211_configure_filter(local);
396 drv_sw_scan_complete(local, scan_sdata);
397 ieee80211_offchannel_return(local);
398 }
399
400 ieee80211_recalc_idle(local);
401
402 ieee80211_mlme_notify_scan_completed(local);
403 ieee80211_ibss_notify_scan_completed(local);
404
405 /* Requeue all the work that might have been ignored while
406 * the scan was in progress; if there was none this will
407 * just be a no-op for the particular interface.
408 */
409 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
410 if (ieee80211_sdata_running(sdata))
411 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
412 }
413
414 if (was_scanning)
415 ieee80211_start_next_roc(local);
416}
417
418void ieee80211_scan_completed(struct ieee80211_hw *hw,
419 struct cfg80211_scan_info *info)
420{
421 struct ieee80211_local *local = hw_to_local(hw);
422
423 trace_api_scan_completed(local, info->aborted);
424
425 set_bit(SCAN_COMPLETED, &local->scanning);
426 if (info->aborted)
427 set_bit(SCAN_ABORTED, &local->scanning);
428
429 memcpy(&local->scan_info, info, sizeof(*info));
430
431 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
432}
433EXPORT_SYMBOL(ieee80211_scan_completed);
434
435static int ieee80211_start_sw_scan(struct ieee80211_local *local,
436 struct ieee80211_sub_if_data *sdata)
437{
438 /* Software scan is not supported in multi-channel cases */
439 if (local->use_chanctx)
440 return -EOPNOTSUPP;
441
442 /*
443 * Hardware/driver doesn't support hw_scan, so use software
444 * scanning instead. First send a nullfunc frame with power save
445 * bit on so that AP will buffer the frames for us while we are not
446 * listening, then send probe requests to each channel and wait for
447 * the responses. After all channels are scanned, tune back to the
448 * original channel and send a nullfunc frame with power save bit
449 * off to trigger the AP to send us all the buffered frames.
450 *
451 * Note that while local->sw_scanning is true everything else but
452 * nullfunc frames and probe requests will be dropped in
453 * ieee80211_tx_h_check_assoc().
454 */
455 drv_sw_scan_start(local, sdata, local->scan_addr);
456
457 local->leave_oper_channel_time = jiffies;
458 local->next_scan_state = SCAN_DECISION;
459 local->scan_channel_idx = 0;
460
461 ieee80211_offchannel_stop_vifs(local);
462
463 /* ensure nullfunc is transmitted before leaving operating channel */
464 ieee80211_flush_queues(local, NULL, false);
465
466 ieee80211_configure_filter(local);
467
468 /* We need to set power level at maximum rate for scanning. */
469 ieee80211_hw_config(local, 0);
470
471 ieee80211_queue_delayed_work(&local->hw,
472 &local->scan_work, 0);
473
474 return 0;
475}
476
477static bool ieee80211_can_scan(struct ieee80211_local *local,
478 struct ieee80211_sub_if_data *sdata)
479{
480 if (ieee80211_is_radar_required(local))
481 return false;
482
483 if (!list_empty(&local->roc_list))
484 return false;
485
486 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
487 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
488 return false;
489
490 return true;
491}
492
493void ieee80211_run_deferred_scan(struct ieee80211_local *local)
494{
495 lockdep_assert_held(&local->mtx);
496
497 if (!local->scan_req || local->scanning)
498 return;
499
500 if (!ieee80211_can_scan(local,
501 rcu_dereference_protected(
502 local->scan_sdata,
503 lockdep_is_held(&local->mtx))))
504 return;
505
506 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
507 round_jiffies_relative(0));
508}
509
510static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
511 unsigned long *next_delay)
512{
513 int i;
514 struct ieee80211_sub_if_data *sdata;
515 struct cfg80211_scan_request *scan_req;
516 enum nl80211_band band = local->hw.conf.chandef.chan->band;
517 u32 tx_flags;
518
519 scan_req = rcu_dereference_protected(local->scan_req,
520 lockdep_is_held(&local->mtx));
521
522 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
523 if (scan_req->no_cck)
524 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
525
526 sdata = rcu_dereference_protected(local->scan_sdata,
527 lockdep_is_held(&local->mtx));
528
529 for (i = 0; i < scan_req->n_ssids; i++)
530 ieee80211_send_probe_req(
531 sdata, local->scan_addr, scan_req->bssid,
532 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
533 scan_req->ie, scan_req->ie_len,
534 scan_req->rates[band], false,
535 tx_flags, local->hw.conf.chandef.chan, true);
536
537 /*
538 * After sending probe requests, wait for probe responses
539 * on the channel.
540 */
541 *next_delay = IEEE80211_CHANNEL_TIME;
542 local->next_scan_state = SCAN_DECISION;
543}
544
545static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
546 struct cfg80211_scan_request *req)
547{
548 struct ieee80211_local *local = sdata->local;
549 int rc;
550
551 lockdep_assert_held(&local->mtx);
552
553 if (local->scan_req || ieee80211_is_radar_required(local))
554 return -EBUSY;
555
556 if (!ieee80211_can_scan(local, sdata)) {
557 /* wait for the work to finish/time out */
558 rcu_assign_pointer(local->scan_req, req);
559 rcu_assign_pointer(local->scan_sdata, sdata);
560 return 0;
561 }
562
563 if (local->ops->hw_scan) {
564 u8 *ies;
565
566 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
567
568 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
569 int i, n_bands = 0;
570 u8 bands_counted = 0;
571
572 for (i = 0; i < req->n_channels; i++) {
573 if (bands_counted & BIT(req->channels[i]->band))
574 continue;
575 bands_counted |= BIT(req->channels[i]->band);
576 n_bands++;
577 }
578
579 local->hw_scan_ies_bufsize *= n_bands;
580 }
581
582 local->hw_scan_req = kmalloc(
583 sizeof(*local->hw_scan_req) +
584 req->n_channels * sizeof(req->channels[0]) +
585 local->hw_scan_ies_bufsize, GFP_KERNEL);
586 if (!local->hw_scan_req)
587 return -ENOMEM;
588
589 local->hw_scan_req->req.ssids = req->ssids;
590 local->hw_scan_req->req.n_ssids = req->n_ssids;
591 ies = (u8 *)local->hw_scan_req +
592 sizeof(*local->hw_scan_req) +
593 req->n_channels * sizeof(req->channels[0]);
594 local->hw_scan_req->req.ie = ies;
595 local->hw_scan_req->req.flags = req->flags;
596 eth_broadcast_addr(local->hw_scan_req->req.bssid);
597 local->hw_scan_req->req.duration = req->duration;
598 local->hw_scan_req->req.duration_mandatory =
599 req->duration_mandatory;
600
601 local->hw_scan_band = 0;
602
603 /*
604 * After allocating local->hw_scan_req, we must
605 * go through until ieee80211_prep_hw_scan(), so
606 * anything that might be changed here and leave
607 * this function early must not go after this
608 * allocation.
609 */
610 }
611
612 rcu_assign_pointer(local->scan_req, req);
613 rcu_assign_pointer(local->scan_sdata, sdata);
614
615 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
616 get_random_mask_addr(local->scan_addr,
617 req->mac_addr,
618 req->mac_addr_mask);
619 else
620 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
621
622 if (local->ops->hw_scan) {
623 __set_bit(SCAN_HW_SCANNING, &local->scanning);
624 } else if ((req->n_channels == 1) &&
625 (req->channels[0] == local->_oper_chandef.chan)) {
626 /*
627 * If we are scanning only on the operating channel
628 * then we do not need to stop normal activities
629 */
630 unsigned long next_delay;
631
632 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
633
634 ieee80211_recalc_idle(local);
635
636 /* Notify driver scan is starting, keep order of operations
637 * same as normal software scan, in case that matters. */
638 drv_sw_scan_start(local, sdata, local->scan_addr);
639
640 ieee80211_configure_filter(local); /* accept probe-responses */
641
642 /* We need to ensure power level is at max for scanning. */
643 ieee80211_hw_config(local, 0);
644
645 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
646 IEEE80211_CHAN_RADAR)) ||
647 !req->n_ssids) {
648 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
649 } else {
650 ieee80211_scan_state_send_probe(local, &next_delay);
651 next_delay = IEEE80211_CHANNEL_TIME;
652 }
653
654 /* Now, just wait a bit and we are all done! */
655 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
656 next_delay);
657 return 0;
658 } else {
659 /* Do normal software scan */
660 __set_bit(SCAN_SW_SCANNING, &local->scanning);
661 }
662
663 ieee80211_recalc_idle(local);
664
665 if (local->ops->hw_scan) {
666 WARN_ON(!ieee80211_prep_hw_scan(local));
667 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
668 } else {
669 rc = ieee80211_start_sw_scan(local, sdata);
670 }
671
672 if (rc) {
673 kfree(local->hw_scan_req);
674 local->hw_scan_req = NULL;
675 local->scanning = 0;
676
677 ieee80211_recalc_idle(local);
678
679 local->scan_req = NULL;
680 RCU_INIT_POINTER(local->scan_sdata, NULL);
681 }
682
683 return rc;
684}
685
686static unsigned long
687ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
688{
689 /*
690 * TODO: channel switching also consumes quite some time,
691 * add that delay as well to get a better estimation
692 */
693 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
694 return IEEE80211_PASSIVE_CHANNEL_TIME;
695 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
696}
697
698static void ieee80211_scan_state_decision(struct ieee80211_local *local,
699 unsigned long *next_delay)
700{
701 bool associated = false;
702 bool tx_empty = true;
703 bool bad_latency;
704 struct ieee80211_sub_if_data *sdata;
705 struct ieee80211_channel *next_chan;
706 enum mac80211_scan_state next_scan_state;
707 struct cfg80211_scan_request *scan_req;
708
709 /*
710 * check if at least one STA interface is associated,
711 * check if at least one STA interface has pending tx frames
712 * and grab the lowest used beacon interval
713 */
714 mutex_lock(&local->iflist_mtx);
715 list_for_each_entry(sdata, &local->interfaces, list) {
716 if (!ieee80211_sdata_running(sdata))
717 continue;
718
719 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
720 if (sdata->u.mgd.associated) {
721 associated = true;
722
723 if (!qdisc_all_tx_empty(sdata->dev)) {
724 tx_empty = false;
725 break;
726 }
727 }
728 }
729 }
730 mutex_unlock(&local->iflist_mtx);
731
732 scan_req = rcu_dereference_protected(local->scan_req,
733 lockdep_is_held(&local->mtx));
734
735 next_chan = scan_req->channels[local->scan_channel_idx];
736
737 /*
738 * we're currently scanning a different channel, let's
739 * see if we can scan another channel without interfering
740 * with the current traffic situation.
741 *
742 * Keep good latency, do not stay off-channel more than 125 ms.
743 */
744
745 bad_latency = time_after(jiffies +
746 ieee80211_scan_get_channel_time(next_chan),
747 local->leave_oper_channel_time + HZ / 8);
748
749 if (associated && !tx_empty) {
750 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
751 next_scan_state = SCAN_ABORT;
752 else
753 next_scan_state = SCAN_SUSPEND;
754 } else if (associated && bad_latency) {
755 next_scan_state = SCAN_SUSPEND;
756 } else {
757 next_scan_state = SCAN_SET_CHANNEL;
758 }
759
760 local->next_scan_state = next_scan_state;
761
762 *next_delay = 0;
763}
764
765static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
766 unsigned long *next_delay)
767{
768 int skip;
769 struct ieee80211_channel *chan;
770 enum nl80211_bss_scan_width oper_scan_width;
771 struct cfg80211_scan_request *scan_req;
772
773 scan_req = rcu_dereference_protected(local->scan_req,
774 lockdep_is_held(&local->mtx));
775
776 skip = 0;
777 chan = scan_req->channels[local->scan_channel_idx];
778
779 local->scan_chandef.chan = chan;
780 local->scan_chandef.center_freq1 = chan->center_freq;
781 local->scan_chandef.center_freq2 = 0;
782 switch (scan_req->scan_width) {
783 case NL80211_BSS_CHAN_WIDTH_5:
784 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
785 break;
786 case NL80211_BSS_CHAN_WIDTH_10:
787 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
788 break;
789 case NL80211_BSS_CHAN_WIDTH_20:
790 /* If scanning on oper channel, use whatever channel-type
791 * is currently in use.
792 */
793 oper_scan_width = cfg80211_chandef_to_scan_width(
794 &local->_oper_chandef);
795 if (chan == local->_oper_chandef.chan &&
796 oper_scan_width == scan_req->scan_width)
797 local->scan_chandef = local->_oper_chandef;
798 else
799 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
800 break;
801 }
802
803 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
804 skip = 1;
805
806 /* advance state machine to next channel/band */
807 local->scan_channel_idx++;
808
809 if (skip) {
810 /* if we skip this channel return to the decision state */
811 local->next_scan_state = SCAN_DECISION;
812 return;
813 }
814
815 /*
816 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
817 * (which unfortunately doesn't say _why_ step a) is done,
818 * but it waits for the probe delay or until a frame is
819 * received - and the received frame would update the NAV).
820 * For now, we do not support waiting until a frame is
821 * received.
822 *
823 * In any case, it is not necessary for a passive scan.
824 */
825 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
826 !scan_req->n_ssids) {
827 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
828 local->next_scan_state = SCAN_DECISION;
829 return;
830 }
831
832 /* active scan, send probes */
833 *next_delay = IEEE80211_PROBE_DELAY;
834 local->next_scan_state = SCAN_SEND_PROBE;
835}
836
837static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
838 unsigned long *next_delay)
839{
840 /* switch back to the operating channel */
841 local->scan_chandef.chan = NULL;
842 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
843
844 /* disable PS */
845 ieee80211_offchannel_return(local);
846
847 *next_delay = HZ / 5;
848 /* afterwards, resume scan & go to next channel */
849 local->next_scan_state = SCAN_RESUME;
850}
851
852static void ieee80211_scan_state_resume(struct ieee80211_local *local,
853 unsigned long *next_delay)
854{
855 ieee80211_offchannel_stop_vifs(local);
856
857 if (local->ops->flush) {
858 ieee80211_flush_queues(local, NULL, false);
859 *next_delay = 0;
860 } else
861 *next_delay = HZ / 10;
862
863 /* remember when we left the operating channel */
864 local->leave_oper_channel_time = jiffies;
865
866 /* advance to the next channel to be scanned */
867 local->next_scan_state = SCAN_SET_CHANNEL;
868}
869
870void ieee80211_scan_work(struct work_struct *work)
871{
872 struct ieee80211_local *local =
873 container_of(work, struct ieee80211_local, scan_work.work);
874 struct ieee80211_sub_if_data *sdata;
875 struct cfg80211_scan_request *scan_req;
876 unsigned long next_delay = 0;
877 bool aborted;
878
879 mutex_lock(&local->mtx);
880
881 if (!ieee80211_can_run_worker(local)) {
882 aborted = true;
883 goto out_complete;
884 }
885
886 sdata = rcu_dereference_protected(local->scan_sdata,
887 lockdep_is_held(&local->mtx));
888 scan_req = rcu_dereference_protected(local->scan_req,
889 lockdep_is_held(&local->mtx));
890
891 /* When scanning on-channel, the first-callback means completed. */
892 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
893 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
894 goto out_complete;
895 }
896
897 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
898 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
899 goto out_complete;
900 }
901
902 if (!sdata || !scan_req)
903 goto out;
904
905 if (!local->scanning) {
906 int rc;
907
908 RCU_INIT_POINTER(local->scan_req, NULL);
909 RCU_INIT_POINTER(local->scan_sdata, NULL);
910
911 rc = __ieee80211_start_scan(sdata, scan_req);
912 if (rc) {
913 /* need to complete scan in cfg80211 */
914 rcu_assign_pointer(local->scan_req, scan_req);
915 aborted = true;
916 goto out_complete;
917 } else
918 goto out;
919 }
920
921 /*
922 * as long as no delay is required advance immediately
923 * without scheduling a new work
924 */
925 do {
926 if (!ieee80211_sdata_running(sdata)) {
927 aborted = true;
928 goto out_complete;
929 }
930
931 switch (local->next_scan_state) {
932 case SCAN_DECISION:
933 /* if no more bands/channels left, complete scan */
934 if (local->scan_channel_idx >= scan_req->n_channels) {
935 aborted = false;
936 goto out_complete;
937 }
938 ieee80211_scan_state_decision(local, &next_delay);
939 break;
940 case SCAN_SET_CHANNEL:
941 ieee80211_scan_state_set_channel(local, &next_delay);
942 break;
943 case SCAN_SEND_PROBE:
944 ieee80211_scan_state_send_probe(local, &next_delay);
945 break;
946 case SCAN_SUSPEND:
947 ieee80211_scan_state_suspend(local, &next_delay);
948 break;
949 case SCAN_RESUME:
950 ieee80211_scan_state_resume(local, &next_delay);
951 break;
952 case SCAN_ABORT:
953 aborted = true;
954 goto out_complete;
955 }
956 } while (next_delay == 0);
957
958 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
959 goto out;
960
961out_complete:
962 __ieee80211_scan_completed(&local->hw, aborted);
963out:
964 mutex_unlock(&local->mtx);
965}
966
967int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
968 struct cfg80211_scan_request *req)
969{
970 int res;
971
972 mutex_lock(&sdata->local->mtx);
973 res = __ieee80211_start_scan(sdata, req);
974 mutex_unlock(&sdata->local->mtx);
975
976 return res;
977}
978
979int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
980 const u8 *ssid, u8 ssid_len,
981 struct ieee80211_channel **channels,
982 unsigned int n_channels,
983 enum nl80211_bss_scan_width scan_width)
984{
985 struct ieee80211_local *local = sdata->local;
986 int ret = -EBUSY, i, n_ch = 0;
987 enum nl80211_band band;
988
989 mutex_lock(&local->mtx);
990
991 /* busy scanning */
992 if (local->scan_req)
993 goto unlock;
994
995 /* fill internal scan request */
996 if (!channels) {
997 int max_n;
998
999 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1000 if (!local->hw.wiphy->bands[band])
1001 continue;
1002
1003 max_n = local->hw.wiphy->bands[band]->n_channels;
1004 for (i = 0; i < max_n; i++) {
1005 struct ieee80211_channel *tmp_ch =
1006 &local->hw.wiphy->bands[band]->channels[i];
1007
1008 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1009 IEEE80211_CHAN_DISABLED))
1010 continue;
1011
1012 local->int_scan_req->channels[n_ch] = tmp_ch;
1013 n_ch++;
1014 }
1015 }
1016
1017 if (WARN_ON_ONCE(n_ch == 0))
1018 goto unlock;
1019
1020 local->int_scan_req->n_channels = n_ch;
1021 } else {
1022 for (i = 0; i < n_channels; i++) {
1023 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1024 IEEE80211_CHAN_DISABLED))
1025 continue;
1026
1027 local->int_scan_req->channels[n_ch] = channels[i];
1028 n_ch++;
1029 }
1030
1031 if (WARN_ON_ONCE(n_ch == 0))
1032 goto unlock;
1033
1034 local->int_scan_req->n_channels = n_ch;
1035 }
1036
1037 local->int_scan_req->ssids = &local->scan_ssid;
1038 local->int_scan_req->n_ssids = 1;
1039 local->int_scan_req->scan_width = scan_width;
1040 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1041 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1042
1043 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1044 unlock:
1045 mutex_unlock(&local->mtx);
1046 return ret;
1047}
1048
1049/*
1050 * Only call this function when a scan can't be queued -- under RTNL.
1051 */
1052void ieee80211_scan_cancel(struct ieee80211_local *local)
1053{
1054 /*
1055 * We are canceling software scan, or deferred scan that was not
1056 * yet really started (see __ieee80211_start_scan ).
1057 *
1058 * Regarding hardware scan:
1059 * - we can not call __ieee80211_scan_completed() as when
1060 * SCAN_HW_SCANNING bit is set this function change
1061 * local->hw_scan_req to operate on 5G band, what race with
1062 * driver which can use local->hw_scan_req
1063 *
1064 * - we can not cancel scan_work since driver can schedule it
1065 * by ieee80211_scan_completed(..., true) to finish scan
1066 *
1067 * Hence we only call the cancel_hw_scan() callback, but the low-level
1068 * driver is still responsible for calling ieee80211_scan_completed()
1069 * after the scan was completed/aborted.
1070 */
1071
1072 mutex_lock(&local->mtx);
1073 if (!local->scan_req)
1074 goto out;
1075
1076 /*
1077 * We have a scan running and the driver already reported completion,
1078 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1079 * cancelled.
1080 */
1081 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1082 test_bit(SCAN_COMPLETED, &local->scanning)) {
1083 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1084 goto out;
1085 }
1086
1087 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1088 /*
1089 * Make sure that __ieee80211_scan_completed doesn't trigger a
1090 * scan on another band.
1091 */
1092 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1093 if (local->ops->cancel_hw_scan)
1094 drv_cancel_hw_scan(local,
1095 rcu_dereference_protected(local->scan_sdata,
1096 lockdep_is_held(&local->mtx)));
1097 goto out;
1098 }
1099
1100 /*
1101 * If the work is currently running, it must be blocked on
1102 * the mutex, but we'll set scan_sdata = NULL and it'll
1103 * simply exit once it acquires the mutex.
1104 */
1105 cancel_delayed_work(&local->scan_work);
1106 /* and clean up */
1107 memset(&local->scan_info, 0, sizeof(local->scan_info));
1108 __ieee80211_scan_completed(&local->hw, true);
1109out:
1110 mutex_unlock(&local->mtx);
1111}
1112
1113int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1114 struct cfg80211_sched_scan_request *req)
1115{
1116 struct ieee80211_local *local = sdata->local;
1117 struct ieee80211_scan_ies sched_scan_ies = {};
1118 struct cfg80211_chan_def chandef;
1119 int ret, i, iebufsz, num_bands = 0;
1120 u32 rate_masks[NUM_NL80211_BANDS] = {};
1121 u8 bands_used = 0;
1122 u8 *ie;
1123 size_t len;
1124
1125 iebufsz = local->scan_ies_len + req->ie_len;
1126
1127 lockdep_assert_held(&local->mtx);
1128
1129 if (!local->ops->sched_scan_start)
1130 return -ENOTSUPP;
1131
1132 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1133 if (local->hw.wiphy->bands[i]) {
1134 bands_used |= BIT(i);
1135 rate_masks[i] = (u32) -1;
1136 num_bands++;
1137 }
1138 }
1139
1140 ie = kzalloc(num_bands * iebufsz, GFP_KERNEL);
1141 if (!ie) {
1142 ret = -ENOMEM;
1143 goto out;
1144 }
1145
1146 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1147
1148 len = ieee80211_build_preq_ies(local, ie, num_bands * iebufsz,
1149 &sched_scan_ies, req->ie,
1150 req->ie_len, bands_used,
1151 rate_masks, &chandef);
1152
1153 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1154 if (ret == 0) {
1155 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1156 rcu_assign_pointer(local->sched_scan_req, req);
1157 }
1158
1159 kfree(ie);
1160
1161out:
1162 if (ret) {
1163 /* Clean in case of failure after HW restart or upon resume. */
1164 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1165 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1166 }
1167
1168 return ret;
1169}
1170
1171int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1172 struct cfg80211_sched_scan_request *req)
1173{
1174 struct ieee80211_local *local = sdata->local;
1175 int ret;
1176
1177 mutex_lock(&local->mtx);
1178
1179 if (rcu_access_pointer(local->sched_scan_sdata)) {
1180 mutex_unlock(&local->mtx);
1181 return -EBUSY;
1182 }
1183
1184 ret = __ieee80211_request_sched_scan_start(sdata, req);
1185
1186 mutex_unlock(&local->mtx);
1187 return ret;
1188}
1189
1190int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1191{
1192 struct ieee80211_sub_if_data *sched_scan_sdata;
1193 int ret = -ENOENT;
1194
1195 mutex_lock(&local->mtx);
1196
1197 if (!local->ops->sched_scan_stop) {
1198 ret = -ENOTSUPP;
1199 goto out;
1200 }
1201
1202 /* We don't want to restart sched scan anymore. */
1203 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1204
1205 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1206 lockdep_is_held(&local->mtx));
1207 if (sched_scan_sdata) {
1208 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1209 if (!ret)
1210 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1211 }
1212out:
1213 mutex_unlock(&local->mtx);
1214
1215 return ret;
1216}
1217
1218void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1219{
1220 struct ieee80211_local *local = hw_to_local(hw);
1221
1222 trace_api_sched_scan_results(local);
1223
1224 cfg80211_sched_scan_results(hw->wiphy);
1225}
1226EXPORT_SYMBOL(ieee80211_sched_scan_results);
1227
1228void ieee80211_sched_scan_end(struct ieee80211_local *local)
1229{
1230 mutex_lock(&local->mtx);
1231
1232 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1233 mutex_unlock(&local->mtx);
1234 return;
1235 }
1236
1237 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1238
1239 /* If sched scan was aborted by the driver. */
1240 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1241
1242 mutex_unlock(&local->mtx);
1243
1244 cfg80211_sched_scan_stopped(local->hw.wiphy);
1245}
1246
1247void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1248{
1249 struct ieee80211_local *local =
1250 container_of(work, struct ieee80211_local,
1251 sched_scan_stopped_work);
1252
1253 ieee80211_sched_scan_end(local);
1254}
1255
1256void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1257{
1258 struct ieee80211_local *local = hw_to_local(hw);
1259
1260 trace_api_sched_scan_stopped(local);
1261
1262 /*
1263 * this shouldn't really happen, so for simplicity
1264 * simply ignore it, and let mac80211 reconfigure
1265 * the sched scan later on.
1266 */
1267 if (local->in_reconfig)
1268 return;
1269
1270 schedule_work(&local->sched_scan_stopped_work);
1271}
1272EXPORT_SYMBOL(ieee80211_sched_scan_stopped);