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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 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 */
14
15#include <linux/if_arp.h>
16#include <linux/etherdevice.h>
17#include <linux/rtnetlink.h>
18#include <linux/pm_qos.h>
19#include <net/sch_generic.h>
20#include <linux/slab.h>
21#include <linux/export.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
32void 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
41static 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
58struct ieee80211_bss *
59ieee80211_bss_info_update(struct ieee80211_local *local,
60 struct ieee80211_rx_status *rx_status,
61 struct ieee80211_mgmt *mgmt, size_t len,
62 struct ieee802_11_elems *elems,
63 struct ieee80211_channel *channel)
64{
65 bool beacon = ieee80211_is_beacon(mgmt->frame_control);
66 struct cfg80211_bss *cbss;
67 struct ieee80211_bss *bss;
68 int clen, srlen;
69 enum nl80211_bss_scan_width scan_width;
70 s32 signal = 0;
71
72 if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
73 signal = rx_status->signal * 100;
74 else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC)
75 signal = (rx_status->signal * 100) / local->hw.max_signal;
76
77 scan_width = NL80211_BSS_CHAN_WIDTH_20;
78 if (rx_status->flag & RX_FLAG_5MHZ)
79 scan_width = NL80211_BSS_CHAN_WIDTH_5;
80 if (rx_status->flag & RX_FLAG_10MHZ)
81 scan_width = NL80211_BSS_CHAN_WIDTH_10;
82
83 cbss = cfg80211_inform_bss_width_frame(local->hw.wiphy, channel,
84 scan_width, mgmt, len, signal,
85 GFP_ATOMIC);
86 if (!cbss)
87 return NULL;
88
89 bss = (void *)cbss->priv;
90
91 if (beacon)
92 bss->device_ts_beacon = rx_status->device_timestamp;
93 else
94 bss->device_ts_presp = rx_status->device_timestamp;
95
96 if (elems->parse_error) {
97 if (beacon)
98 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
99 else
100 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
101 } else {
102 if (beacon)
103 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
104 else
105 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
106 }
107
108 /* save the ERP value so that it is available at association time */
109 if (elems->erp_info && (!elems->parse_error ||
110 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
111 bss->erp_value = elems->erp_info[0];
112 bss->has_erp_value = true;
113 if (!elems->parse_error)
114 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
115 }
116
117 /* replace old supported rates if we get new values */
118 if (!elems->parse_error ||
119 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
120 srlen = 0;
121 if (elems->supp_rates) {
122 clen = IEEE80211_MAX_SUPP_RATES;
123 if (clen > elems->supp_rates_len)
124 clen = elems->supp_rates_len;
125 memcpy(bss->supp_rates, elems->supp_rates, clen);
126 srlen += clen;
127 }
128 if (elems->ext_supp_rates) {
129 clen = IEEE80211_MAX_SUPP_RATES - srlen;
130 if (clen > elems->ext_supp_rates_len)
131 clen = elems->ext_supp_rates_len;
132 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
133 clen);
134 srlen += clen;
135 }
136 if (srlen) {
137 bss->supp_rates_len = srlen;
138 if (!elems->parse_error)
139 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
140 }
141 }
142
143 if (!elems->parse_error ||
144 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
145 bss->wmm_used = elems->wmm_param || elems->wmm_info;
146 bss->uapsd_supported = is_uapsd_supported(elems);
147 if (!elems->parse_error)
148 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
149 }
150
151 if (beacon) {
152 struct ieee80211_supported_band *sband =
153 local->hw.wiphy->bands[rx_status->band];
154 if (!(rx_status->flag & RX_FLAG_HT) &&
155 !(rx_status->flag & RX_FLAG_VHT))
156 bss->beacon_rate =
157 &sband->bitrates[rx_status->rate_idx];
158 }
159
160 return bss;
161}
162
163void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
164{
165 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
166 struct ieee80211_sub_if_data *sdata1, *sdata2;
167 struct ieee80211_mgmt *mgmt = (void *)skb->data;
168 struct ieee80211_bss *bss;
169 u8 *elements;
170 struct ieee80211_channel *channel;
171 size_t baselen;
172 struct ieee802_11_elems elems;
173
174 if (skb->len < 24 ||
175 (!ieee80211_is_probe_resp(mgmt->frame_control) &&
176 !ieee80211_is_beacon(mgmt->frame_control)))
177 return;
178
179 sdata1 = rcu_dereference(local->scan_sdata);
180 sdata2 = rcu_dereference(local->sched_scan_sdata);
181
182 if (likely(!sdata1 && !sdata2))
183 return;
184
185 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
186 /* ignore ProbeResp to foreign address */
187 if ((!sdata1 || !ether_addr_equal(mgmt->da, sdata1->vif.addr)) &&
188 (!sdata2 || !ether_addr_equal(mgmt->da, sdata2->vif.addr)))
189 return;
190
191 elements = mgmt->u.probe_resp.variable;
192 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
193 } else {
194 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
195 elements = mgmt->u.beacon.variable;
196 }
197
198 if (baselen > skb->len)
199 return;
200
201 ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems);
202
203 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
204
205 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
206 return;
207
208 bss = ieee80211_bss_info_update(local, rx_status,
209 mgmt, skb->len, &elems,
210 channel);
211 if (bss)
212 ieee80211_rx_bss_put(local, bss);
213}
214
215static void
216ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
217 enum nl80211_bss_scan_width scan_width)
218{
219 memset(chandef, 0, sizeof(*chandef));
220 switch (scan_width) {
221 case NL80211_BSS_CHAN_WIDTH_5:
222 chandef->width = NL80211_CHAN_WIDTH_5;
223 break;
224 case NL80211_BSS_CHAN_WIDTH_10:
225 chandef->width = NL80211_CHAN_WIDTH_10;
226 break;
227 default:
228 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
229 break;
230 }
231}
232
233/* return false if no more work */
234static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
235{
236 struct cfg80211_scan_request *req = local->scan_req;
237 struct cfg80211_chan_def chandef;
238 enum ieee80211_band band;
239 int i, ielen, n_chans;
240
241 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
242 return false;
243
244 do {
245 if (local->hw_scan_band == IEEE80211_NUM_BANDS)
246 return false;
247
248 band = local->hw_scan_band;
249 n_chans = 0;
250 for (i = 0; i < req->n_channels; i++) {
251 if (req->channels[i]->band == band) {
252 local->hw_scan_req->channels[n_chans] =
253 req->channels[i];
254 n_chans++;
255 }
256 }
257
258 local->hw_scan_band++;
259 } while (!n_chans);
260
261 local->hw_scan_req->n_channels = n_chans;
262 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
263
264 ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie,
265 local->hw_scan_ies_bufsize,
266 req->ie, req->ie_len, band,
267 req->rates[band], &chandef);
268 local->hw_scan_req->ie_len = ielen;
269 local->hw_scan_req->no_cck = req->no_cck;
270
271 return true;
272}
273
274static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
275{
276 struct ieee80211_local *local = hw_to_local(hw);
277 bool hw_scan = local->ops->hw_scan;
278 bool was_scanning = local->scanning;
279
280 lockdep_assert_held(&local->mtx);
281
282 /*
283 * It's ok to abort a not-yet-running scan (that
284 * we have one at all will be verified by checking
285 * local->scan_req next), but not to complete it
286 * successfully.
287 */
288 if (WARN_ON(!local->scanning && !aborted))
289 aborted = true;
290
291 if (WARN_ON(!local->scan_req))
292 return;
293
294 if (hw_scan && !aborted && ieee80211_prep_hw_scan(local)) {
295 int rc;
296
297 rc = drv_hw_scan(local,
298 rcu_dereference_protected(local->scan_sdata,
299 lockdep_is_held(&local->mtx)),
300 local->hw_scan_req);
301
302 if (rc == 0)
303 return;
304 }
305
306 kfree(local->hw_scan_req);
307 local->hw_scan_req = NULL;
308
309 if (local->scan_req != local->int_scan_req)
310 cfg80211_scan_done(local->scan_req, aborted);
311 local->scan_req = NULL;
312 rcu_assign_pointer(local->scan_sdata, NULL);
313
314 local->scanning = 0;
315 local->scan_chandef.chan = NULL;
316
317 /* Set power back to normal operating levels. */
318 ieee80211_hw_config(local, 0);
319
320 if (!hw_scan) {
321 ieee80211_configure_filter(local);
322 drv_sw_scan_complete(local);
323 ieee80211_offchannel_return(local);
324 }
325
326 ieee80211_recalc_idle(local);
327
328 ieee80211_mlme_notify_scan_completed(local);
329 ieee80211_ibss_notify_scan_completed(local);
330 ieee80211_mesh_notify_scan_completed(local);
331 if (was_scanning)
332 ieee80211_start_next_roc(local);
333}
334
335void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
336{
337 struct ieee80211_local *local = hw_to_local(hw);
338
339 trace_api_scan_completed(local, aborted);
340
341 set_bit(SCAN_COMPLETED, &local->scanning);
342 if (aborted)
343 set_bit(SCAN_ABORTED, &local->scanning);
344 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
345}
346EXPORT_SYMBOL(ieee80211_scan_completed);
347
348static int ieee80211_start_sw_scan(struct ieee80211_local *local)
349{
350 /* Software scan is not supported in multi-channel cases */
351 if (local->use_chanctx)
352 return -EOPNOTSUPP;
353
354 /*
355 * Hardware/driver doesn't support hw_scan, so use software
356 * scanning instead. First send a nullfunc frame with power save
357 * bit on so that AP will buffer the frames for us while we are not
358 * listening, then send probe requests to each channel and wait for
359 * the responses. After all channels are scanned, tune back to the
360 * original channel and send a nullfunc frame with power save bit
361 * off to trigger the AP to send us all the buffered frames.
362 *
363 * Note that while local->sw_scanning is true everything else but
364 * nullfunc frames and probe requests will be dropped in
365 * ieee80211_tx_h_check_assoc().
366 */
367 drv_sw_scan_start(local);
368
369 local->leave_oper_channel_time = jiffies;
370 local->next_scan_state = SCAN_DECISION;
371 local->scan_channel_idx = 0;
372
373 ieee80211_offchannel_stop_vifs(local);
374
375 /* ensure nullfunc is transmitted before leaving operating channel */
376 ieee80211_flush_queues(local, NULL);
377
378 ieee80211_configure_filter(local);
379
380 /* We need to set power level at maximum rate for scanning. */
381 ieee80211_hw_config(local, 0);
382
383 ieee80211_queue_delayed_work(&local->hw,
384 &local->scan_work, 0);
385
386 return 0;
387}
388
389static bool ieee80211_can_scan(struct ieee80211_local *local,
390 struct ieee80211_sub_if_data *sdata)
391{
392 if (local->radar_detect_enabled)
393 return false;
394
395 if (!list_empty(&local->roc_list))
396 return false;
397
398 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
399 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
400 return false;
401
402 return true;
403}
404
405void ieee80211_run_deferred_scan(struct ieee80211_local *local)
406{
407 lockdep_assert_held(&local->mtx);
408
409 if (!local->scan_req || local->scanning)
410 return;
411
412 if (!ieee80211_can_scan(local,
413 rcu_dereference_protected(
414 local->scan_sdata,
415 lockdep_is_held(&local->mtx))))
416 return;
417
418 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
419 round_jiffies_relative(0));
420}
421
422static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
423 unsigned long *next_delay)
424{
425 int i;
426 struct ieee80211_sub_if_data *sdata;
427 enum ieee80211_band band = local->hw.conf.chandef.chan->band;
428 u32 tx_flags;
429
430 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
431 if (local->scan_req->no_cck)
432 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
433
434 sdata = rcu_dereference_protected(local->scan_sdata,
435 lockdep_is_held(&local->mtx));
436
437 for (i = 0; i < local->scan_req->n_ssids; i++)
438 ieee80211_send_probe_req(
439 sdata, NULL,
440 local->scan_req->ssids[i].ssid,
441 local->scan_req->ssids[i].ssid_len,
442 local->scan_req->ie, local->scan_req->ie_len,
443 local->scan_req->rates[band], false,
444 tx_flags, local->hw.conf.chandef.chan, true);
445
446 /*
447 * After sending probe requests, wait for probe responses
448 * on the channel.
449 */
450 *next_delay = IEEE80211_CHANNEL_TIME;
451 local->next_scan_state = SCAN_DECISION;
452}
453
454static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
455 struct cfg80211_scan_request *req)
456{
457 struct ieee80211_local *local = sdata->local;
458 int rc;
459
460 lockdep_assert_held(&local->mtx);
461
462 if (local->scan_req)
463 return -EBUSY;
464
465 if (!ieee80211_can_scan(local, sdata)) {
466 /* wait for the work to finish/time out */
467 local->scan_req = req;
468 rcu_assign_pointer(local->scan_sdata, sdata);
469 return 0;
470 }
471
472 if (local->ops->hw_scan) {
473 u8 *ies;
474
475 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
476 local->hw_scan_req = kmalloc(
477 sizeof(*local->hw_scan_req) +
478 req->n_channels * sizeof(req->channels[0]) +
479 local->hw_scan_ies_bufsize, GFP_KERNEL);
480 if (!local->hw_scan_req)
481 return -ENOMEM;
482
483 local->hw_scan_req->ssids = req->ssids;
484 local->hw_scan_req->n_ssids = req->n_ssids;
485 ies = (u8 *)local->hw_scan_req +
486 sizeof(*local->hw_scan_req) +
487 req->n_channels * sizeof(req->channels[0]);
488 local->hw_scan_req->ie = ies;
489 local->hw_scan_req->flags = req->flags;
490
491 local->hw_scan_band = 0;
492
493 /*
494 * After allocating local->hw_scan_req, we must
495 * go through until ieee80211_prep_hw_scan(), so
496 * anything that might be changed here and leave
497 * this function early must not go after this
498 * allocation.
499 */
500 }
501
502 local->scan_req = req;
503 rcu_assign_pointer(local->scan_sdata, sdata);
504
505 if (local->ops->hw_scan) {
506 __set_bit(SCAN_HW_SCANNING, &local->scanning);
507 } else if ((req->n_channels == 1) &&
508 (req->channels[0] == local->_oper_chandef.chan)) {
509 /*
510 * If we are scanning only on the operating channel
511 * then we do not need to stop normal activities
512 */
513 unsigned long next_delay;
514
515 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
516
517 ieee80211_recalc_idle(local);
518
519 /* Notify driver scan is starting, keep order of operations
520 * same as normal software scan, in case that matters. */
521 drv_sw_scan_start(local);
522
523 ieee80211_configure_filter(local); /* accept probe-responses */
524
525 /* We need to ensure power level is at max for scanning. */
526 ieee80211_hw_config(local, 0);
527
528 if ((req->channels[0]->flags &
529 IEEE80211_CHAN_NO_IR) ||
530 !local->scan_req->n_ssids) {
531 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
532 } else {
533 ieee80211_scan_state_send_probe(local, &next_delay);
534 next_delay = IEEE80211_CHANNEL_TIME;
535 }
536
537 /* Now, just wait a bit and we are all done! */
538 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
539 next_delay);
540 return 0;
541 } else {
542 /* Do normal software scan */
543 __set_bit(SCAN_SW_SCANNING, &local->scanning);
544 }
545
546 ieee80211_recalc_idle(local);
547
548 if (local->ops->hw_scan) {
549 WARN_ON(!ieee80211_prep_hw_scan(local));
550 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
551 } else
552 rc = ieee80211_start_sw_scan(local);
553
554 if (rc) {
555 kfree(local->hw_scan_req);
556 local->hw_scan_req = NULL;
557 local->scanning = 0;
558
559 ieee80211_recalc_idle(local);
560
561 local->scan_req = NULL;
562 rcu_assign_pointer(local->scan_sdata, NULL);
563 }
564
565 return rc;
566}
567
568static unsigned long
569ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
570{
571 /*
572 * TODO: channel switching also consumes quite some time,
573 * add that delay as well to get a better estimation
574 */
575 if (chan->flags & IEEE80211_CHAN_NO_IR)
576 return IEEE80211_PASSIVE_CHANNEL_TIME;
577 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
578}
579
580static void ieee80211_scan_state_decision(struct ieee80211_local *local,
581 unsigned long *next_delay)
582{
583 bool associated = false;
584 bool tx_empty = true;
585 bool bad_latency;
586 struct ieee80211_sub_if_data *sdata;
587 struct ieee80211_channel *next_chan;
588 enum mac80211_scan_state next_scan_state;
589
590 /*
591 * check if at least one STA interface is associated,
592 * check if at least one STA interface has pending tx frames
593 * and grab the lowest used beacon interval
594 */
595 mutex_lock(&local->iflist_mtx);
596 list_for_each_entry(sdata, &local->interfaces, list) {
597 if (!ieee80211_sdata_running(sdata))
598 continue;
599
600 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
601 if (sdata->u.mgd.associated) {
602 associated = true;
603
604 if (!qdisc_all_tx_empty(sdata->dev)) {
605 tx_empty = false;
606 break;
607 }
608 }
609 }
610 }
611 mutex_unlock(&local->iflist_mtx);
612
613 next_chan = local->scan_req->channels[local->scan_channel_idx];
614
615 /*
616 * we're currently scanning a different channel, let's
617 * see if we can scan another channel without interfering
618 * with the current traffic situation.
619 *
620 * Keep good latency, do not stay off-channel more than 125 ms.
621 */
622
623 bad_latency = time_after(jiffies +
624 ieee80211_scan_get_channel_time(next_chan),
625 local->leave_oper_channel_time + HZ / 8);
626
627 if (associated && !tx_empty) {
628 if (local->scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
629 next_scan_state = SCAN_ABORT;
630 else
631 next_scan_state = SCAN_SUSPEND;
632 } else if (associated && bad_latency) {
633 next_scan_state = SCAN_SUSPEND;
634 } else {
635 next_scan_state = SCAN_SET_CHANNEL;
636 }
637
638 local->next_scan_state = next_scan_state;
639
640 *next_delay = 0;
641}
642
643static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
644 unsigned long *next_delay)
645{
646 int skip;
647 struct ieee80211_channel *chan;
648 enum nl80211_bss_scan_width oper_scan_width;
649
650 skip = 0;
651 chan = local->scan_req->channels[local->scan_channel_idx];
652
653 local->scan_chandef.chan = chan;
654 local->scan_chandef.center_freq1 = chan->center_freq;
655 local->scan_chandef.center_freq2 = 0;
656 switch (local->scan_req->scan_width) {
657 case NL80211_BSS_CHAN_WIDTH_5:
658 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
659 break;
660 case NL80211_BSS_CHAN_WIDTH_10:
661 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
662 break;
663 case NL80211_BSS_CHAN_WIDTH_20:
664 /* If scanning on oper channel, use whatever channel-type
665 * is currently in use.
666 */
667 oper_scan_width = cfg80211_chandef_to_scan_width(
668 &local->_oper_chandef);
669 if (chan == local->_oper_chandef.chan &&
670 oper_scan_width == local->scan_req->scan_width)
671 local->scan_chandef = local->_oper_chandef;
672 else
673 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
674 break;
675 }
676
677 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
678 skip = 1;
679
680 /* advance state machine to next channel/band */
681 local->scan_channel_idx++;
682
683 if (skip) {
684 /* if we skip this channel return to the decision state */
685 local->next_scan_state = SCAN_DECISION;
686 return;
687 }
688
689 /*
690 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
691 * (which unfortunately doesn't say _why_ step a) is done,
692 * but it waits for the probe delay or until a frame is
693 * received - and the received frame would update the NAV).
694 * For now, we do not support waiting until a frame is
695 * received.
696 *
697 * In any case, it is not necessary for a passive scan.
698 */
699 if (chan->flags & IEEE80211_CHAN_NO_IR ||
700 !local->scan_req->n_ssids) {
701 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
702 local->next_scan_state = SCAN_DECISION;
703 return;
704 }
705
706 /* active scan, send probes */
707 *next_delay = IEEE80211_PROBE_DELAY;
708 local->next_scan_state = SCAN_SEND_PROBE;
709}
710
711static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
712 unsigned long *next_delay)
713{
714 /* switch back to the operating channel */
715 local->scan_chandef.chan = NULL;
716 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
717
718 /* disable PS */
719 ieee80211_offchannel_return(local);
720
721 *next_delay = HZ / 5;
722 /* afterwards, resume scan & go to next channel */
723 local->next_scan_state = SCAN_RESUME;
724}
725
726static void ieee80211_scan_state_resume(struct ieee80211_local *local,
727 unsigned long *next_delay)
728{
729 ieee80211_offchannel_stop_vifs(local);
730
731 if (local->ops->flush) {
732 ieee80211_flush_queues(local, NULL);
733 *next_delay = 0;
734 } else
735 *next_delay = HZ / 10;
736
737 /* remember when we left the operating channel */
738 local->leave_oper_channel_time = jiffies;
739
740 /* advance to the next channel to be scanned */
741 local->next_scan_state = SCAN_SET_CHANNEL;
742}
743
744void ieee80211_scan_work(struct work_struct *work)
745{
746 struct ieee80211_local *local =
747 container_of(work, struct ieee80211_local, scan_work.work);
748 struct ieee80211_sub_if_data *sdata;
749 unsigned long next_delay = 0;
750 bool aborted;
751
752 mutex_lock(&local->mtx);
753
754 sdata = rcu_dereference_protected(local->scan_sdata,
755 lockdep_is_held(&local->mtx));
756
757 /* When scanning on-channel, the first-callback means completed. */
758 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
759 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
760 goto out_complete;
761 }
762
763 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
764 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
765 goto out_complete;
766 }
767
768 if (!sdata || !local->scan_req)
769 goto out;
770
771 if (local->scan_req && !local->scanning) {
772 struct cfg80211_scan_request *req = local->scan_req;
773 int rc;
774
775 local->scan_req = NULL;
776 rcu_assign_pointer(local->scan_sdata, NULL);
777
778 rc = __ieee80211_start_scan(sdata, req);
779 if (rc) {
780 /* need to complete scan in cfg80211 */
781 local->scan_req = req;
782 aborted = true;
783 goto out_complete;
784 } else
785 goto out;
786 }
787
788 /*
789 * as long as no delay is required advance immediately
790 * without scheduling a new work
791 */
792 do {
793 if (!ieee80211_sdata_running(sdata)) {
794 aborted = true;
795 goto out_complete;
796 }
797
798 switch (local->next_scan_state) {
799 case SCAN_DECISION:
800 /* if no more bands/channels left, complete scan */
801 if (local->scan_channel_idx >= local->scan_req->n_channels) {
802 aborted = false;
803 goto out_complete;
804 }
805 ieee80211_scan_state_decision(local, &next_delay);
806 break;
807 case SCAN_SET_CHANNEL:
808 ieee80211_scan_state_set_channel(local, &next_delay);
809 break;
810 case SCAN_SEND_PROBE:
811 ieee80211_scan_state_send_probe(local, &next_delay);
812 break;
813 case SCAN_SUSPEND:
814 ieee80211_scan_state_suspend(local, &next_delay);
815 break;
816 case SCAN_RESUME:
817 ieee80211_scan_state_resume(local, &next_delay);
818 break;
819 case SCAN_ABORT:
820 aborted = true;
821 goto out_complete;
822 }
823 } while (next_delay == 0);
824
825 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
826 goto out;
827
828out_complete:
829 __ieee80211_scan_completed(&local->hw, aborted);
830out:
831 mutex_unlock(&local->mtx);
832}
833
834int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
835 struct cfg80211_scan_request *req)
836{
837 int res;
838
839 mutex_lock(&sdata->local->mtx);
840 res = __ieee80211_start_scan(sdata, req);
841 mutex_unlock(&sdata->local->mtx);
842
843 return res;
844}
845
846int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
847 const u8 *ssid, u8 ssid_len,
848 struct ieee80211_channel *chan,
849 enum nl80211_bss_scan_width scan_width)
850{
851 struct ieee80211_local *local = sdata->local;
852 int ret = -EBUSY;
853 enum ieee80211_band band;
854
855 mutex_lock(&local->mtx);
856
857 /* busy scanning */
858 if (local->scan_req)
859 goto unlock;
860
861 /* fill internal scan request */
862 if (!chan) {
863 int i, max_n;
864 int n_ch = 0;
865
866 for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
867 if (!local->hw.wiphy->bands[band])
868 continue;
869
870 max_n = local->hw.wiphy->bands[band]->n_channels;
871 for (i = 0; i < max_n; i++) {
872 struct ieee80211_channel *tmp_ch =
873 &local->hw.wiphy->bands[band]->channels[i];
874
875 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
876 IEEE80211_CHAN_DISABLED))
877 continue;
878
879 local->int_scan_req->channels[n_ch] = tmp_ch;
880 n_ch++;
881 }
882 }
883
884 if (WARN_ON_ONCE(n_ch == 0))
885 goto unlock;
886
887 local->int_scan_req->n_channels = n_ch;
888 } else {
889 if (WARN_ON_ONCE(chan->flags & (IEEE80211_CHAN_NO_IR |
890 IEEE80211_CHAN_DISABLED)))
891 goto unlock;
892
893 local->int_scan_req->channels[0] = chan;
894 local->int_scan_req->n_channels = 1;
895 }
896
897 local->int_scan_req->ssids = &local->scan_ssid;
898 local->int_scan_req->n_ssids = 1;
899 local->int_scan_req->scan_width = scan_width;
900 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
901 local->int_scan_req->ssids[0].ssid_len = ssid_len;
902
903 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
904 unlock:
905 mutex_unlock(&local->mtx);
906 return ret;
907}
908
909/*
910 * Only call this function when a scan can't be queued -- under RTNL.
911 */
912void ieee80211_scan_cancel(struct ieee80211_local *local)
913{
914 /*
915 * We are canceling software scan, or deferred scan that was not
916 * yet really started (see __ieee80211_start_scan ).
917 *
918 * Regarding hardware scan:
919 * - we can not call __ieee80211_scan_completed() as when
920 * SCAN_HW_SCANNING bit is set this function change
921 * local->hw_scan_req to operate on 5G band, what race with
922 * driver which can use local->hw_scan_req
923 *
924 * - we can not cancel scan_work since driver can schedule it
925 * by ieee80211_scan_completed(..., true) to finish scan
926 *
927 * Hence we only call the cancel_hw_scan() callback, but the low-level
928 * driver is still responsible for calling ieee80211_scan_completed()
929 * after the scan was completed/aborted.
930 */
931
932 mutex_lock(&local->mtx);
933 if (!local->scan_req)
934 goto out;
935
936 /*
937 * We have a scan running and the driver already reported completion,
938 * but the worker hasn't run yet or is stuck on the mutex - mark it as
939 * cancelled.
940 */
941 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
942 test_bit(SCAN_COMPLETED, &local->scanning)) {
943 set_bit(SCAN_HW_CANCELLED, &local->scanning);
944 goto out;
945 }
946
947 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
948 /*
949 * Make sure that __ieee80211_scan_completed doesn't trigger a
950 * scan on another band.
951 */
952 set_bit(SCAN_HW_CANCELLED, &local->scanning);
953 if (local->ops->cancel_hw_scan)
954 drv_cancel_hw_scan(local,
955 rcu_dereference_protected(local->scan_sdata,
956 lockdep_is_held(&local->mtx)));
957 goto out;
958 }
959
960 /*
961 * If the work is currently running, it must be blocked on
962 * the mutex, but we'll set scan_sdata = NULL and it'll
963 * simply exit once it acquires the mutex.
964 */
965 cancel_delayed_work(&local->scan_work);
966 /* and clean up */
967 __ieee80211_scan_completed(&local->hw, true);
968out:
969 mutex_unlock(&local->mtx);
970}
971
972int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
973 struct cfg80211_sched_scan_request *req)
974{
975 struct ieee80211_local *local = sdata->local;
976 struct ieee80211_sched_scan_ies sched_scan_ies = {};
977 struct cfg80211_chan_def chandef;
978 int ret, i, iebufsz;
979
980 iebufsz = local->scan_ies_len + req->ie_len;
981
982 lockdep_assert_held(&local->mtx);
983
984 if (!local->ops->sched_scan_start)
985 return -ENOTSUPP;
986
987 for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
988 if (!local->hw.wiphy->bands[i])
989 continue;
990
991 sched_scan_ies.ie[i] = kzalloc(iebufsz, GFP_KERNEL);
992 if (!sched_scan_ies.ie[i]) {
993 ret = -ENOMEM;
994 goto out_free;
995 }
996
997 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
998
999 sched_scan_ies.len[i] =
1000 ieee80211_build_preq_ies(local, sched_scan_ies.ie[i],
1001 iebufsz, req->ie, req->ie_len,
1002 i, (u32) -1, &chandef);
1003 }
1004
1005 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1006 if (ret == 0) {
1007 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1008 local->sched_scan_req = req;
1009 }
1010
1011out_free:
1012 while (i > 0)
1013 kfree(sched_scan_ies.ie[--i]);
1014
1015 if (ret) {
1016 /* Clean in case of failure after HW restart or upon resume. */
1017 rcu_assign_pointer(local->sched_scan_sdata, NULL);
1018 local->sched_scan_req = NULL;
1019 }
1020
1021 return ret;
1022}
1023
1024int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1025 struct cfg80211_sched_scan_request *req)
1026{
1027 struct ieee80211_local *local = sdata->local;
1028 int ret;
1029
1030 mutex_lock(&local->mtx);
1031
1032 if (rcu_access_pointer(local->sched_scan_sdata)) {
1033 mutex_unlock(&local->mtx);
1034 return -EBUSY;
1035 }
1036
1037 ret = __ieee80211_request_sched_scan_start(sdata, req);
1038
1039 mutex_unlock(&local->mtx);
1040 return ret;
1041}
1042
1043int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata)
1044{
1045 struct ieee80211_local *local = sdata->local;
1046 int ret = 0;
1047
1048 mutex_lock(&local->mtx);
1049
1050 if (!local->ops->sched_scan_stop) {
1051 ret = -ENOTSUPP;
1052 goto out;
1053 }
1054
1055 /* We don't want to restart sched scan anymore. */
1056 local->sched_scan_req = NULL;
1057
1058 if (rcu_access_pointer(local->sched_scan_sdata)) {
1059 ret = drv_sched_scan_stop(local, sdata);
1060 if (!ret)
1061 rcu_assign_pointer(local->sched_scan_sdata, NULL);
1062 }
1063out:
1064 mutex_unlock(&local->mtx);
1065
1066 return ret;
1067}
1068
1069void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1070{
1071 struct ieee80211_local *local = hw_to_local(hw);
1072
1073 trace_api_sched_scan_results(local);
1074
1075 cfg80211_sched_scan_results(hw->wiphy);
1076}
1077EXPORT_SYMBOL(ieee80211_sched_scan_results);
1078
1079void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1080{
1081 struct ieee80211_local *local =
1082 container_of(work, struct ieee80211_local,
1083 sched_scan_stopped_work);
1084
1085 mutex_lock(&local->mtx);
1086
1087 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1088 mutex_unlock(&local->mtx);
1089 return;
1090 }
1091
1092 rcu_assign_pointer(local->sched_scan_sdata, NULL);
1093
1094 /* If sched scan was aborted by the driver. */
1095 local->sched_scan_req = NULL;
1096
1097 mutex_unlock(&local->mtx);
1098
1099 cfg80211_sched_scan_stopped(local->hw.wiphy);
1100}
1101
1102void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1103{
1104 struct ieee80211_local *local = hw_to_local(hw);
1105
1106 trace_api_sched_scan_stopped(local);
1107
1108 schedule_work(&local->sched_scan_stopped_work);
1109}
1110EXPORT_SYMBOL(ieee80211_sched_scan_stopped);