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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 / 8)
31
32static void ieee80211_rx_bss_free(struct cfg80211_bss *cbss)
33{
34 struct ieee80211_bss *bss = (void *)cbss->priv;
35
36 kfree(bss_mesh_id(bss));
37 kfree(bss_mesh_cfg(bss));
38}
39
40void ieee80211_rx_bss_put(struct ieee80211_local *local,
41 struct ieee80211_bss *bss)
42{
43 if (!bss)
44 return;
45 cfg80211_put_bss(container_of((void *)bss, struct cfg80211_bss, priv));
46}
47
48static bool is_uapsd_supported(struct ieee802_11_elems *elems)
49{
50 u8 qos_info;
51
52 if (elems->wmm_info && elems->wmm_info_len == 7
53 && elems->wmm_info[5] == 1)
54 qos_info = elems->wmm_info[6];
55 else if (elems->wmm_param && elems->wmm_param_len == 24
56 && elems->wmm_param[5] == 1)
57 qos_info = elems->wmm_param[6];
58 else
59 /* no valid wmm information or parameter element found */
60 return false;
61
62 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
63}
64
65struct ieee80211_bss *
66ieee80211_bss_info_update(struct ieee80211_local *local,
67 struct ieee80211_rx_status *rx_status,
68 struct ieee80211_mgmt *mgmt,
69 size_t len,
70 struct ieee802_11_elems *elems,
71 struct ieee80211_channel *channel,
72 bool beacon)
73{
74 struct cfg80211_bss *cbss;
75 struct ieee80211_bss *bss;
76 int clen, srlen;
77 s32 signal = 0;
78
79 if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
80 signal = rx_status->signal * 100;
81 else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC)
82 signal = (rx_status->signal * 100) / local->hw.max_signal;
83
84 cbss = cfg80211_inform_bss_frame(local->hw.wiphy, channel,
85 mgmt, len, signal, GFP_ATOMIC);
86
87 if (!cbss)
88 return NULL;
89
90 cbss->free_priv = ieee80211_rx_bss_free;
91 bss = (void *)cbss->priv;
92
93 if (elems->parse_error) {
94 if (beacon)
95 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
96 else
97 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
98 } else {
99 if (beacon)
100 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
101 else
102 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
103 }
104
105 /* save the ERP value so that it is available at association time */
106 if (elems->erp_info && elems->erp_info_len >= 1 &&
107 (!elems->parse_error ||
108 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
109 bss->erp_value = elems->erp_info[0];
110 bss->has_erp_value = true;
111 if (!elems->parse_error)
112 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
113 }
114
115 if (elems->tim && (!elems->parse_error ||
116 !(bss->valid_data & IEEE80211_BSS_VALID_DTIM))) {
117 struct ieee80211_tim_ie *tim_ie =
118 (struct ieee80211_tim_ie *)elems->tim;
119 bss->dtim_period = tim_ie->dtim_period;
120 if (!elems->parse_error)
121 bss->valid_data |= IEEE80211_BSS_VALID_DTIM;
122 }
123
124 /* If the beacon had no TIM IE, or it was invalid, use 1 */
125 if (beacon && !bss->dtim_period)
126 bss->dtim_period = 1;
127
128 /* replace old supported rates if we get new values */
129 if (!elems->parse_error ||
130 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
131 srlen = 0;
132 if (elems->supp_rates) {
133 clen = IEEE80211_MAX_SUPP_RATES;
134 if (clen > elems->supp_rates_len)
135 clen = elems->supp_rates_len;
136 memcpy(bss->supp_rates, elems->supp_rates, clen);
137 srlen += clen;
138 }
139 if (elems->ext_supp_rates) {
140 clen = IEEE80211_MAX_SUPP_RATES - srlen;
141 if (clen > elems->ext_supp_rates_len)
142 clen = elems->ext_supp_rates_len;
143 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
144 clen);
145 srlen += clen;
146 }
147 if (srlen) {
148 bss->supp_rates_len = srlen;
149 if (!elems->parse_error)
150 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
151 }
152 }
153
154 if (!elems->parse_error ||
155 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
156 bss->wmm_used = elems->wmm_param || elems->wmm_info;
157 bss->uapsd_supported = is_uapsd_supported(elems);
158 if (!elems->parse_error)
159 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
160 }
161
162 if (!beacon)
163 bss->last_probe_resp = jiffies;
164
165 return bss;
166}
167
168ieee80211_rx_result
169ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
170{
171 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
172 struct ieee80211_mgmt *mgmt;
173 struct ieee80211_bss *bss;
174 u8 *elements;
175 struct ieee80211_channel *channel;
176 size_t baselen;
177 int freq;
178 __le16 fc;
179 bool presp, beacon = false;
180 struct ieee802_11_elems elems;
181
182 if (skb->len < 2)
183 return RX_DROP_UNUSABLE;
184
185 mgmt = (struct ieee80211_mgmt *) skb->data;
186 fc = mgmt->frame_control;
187
188 if (ieee80211_is_ctl(fc))
189 return RX_CONTINUE;
190
191 if (skb->len < 24)
192 return RX_CONTINUE;
193
194 presp = ieee80211_is_probe_resp(fc);
195 if (presp) {
196 /* ignore ProbeResp to foreign address */
197 if (!ether_addr_equal(mgmt->da, sdata->vif.addr))
198 return RX_DROP_MONITOR;
199
200 presp = true;
201 elements = mgmt->u.probe_resp.variable;
202 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
203 } else {
204 beacon = ieee80211_is_beacon(fc);
205 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
206 elements = mgmt->u.beacon.variable;
207 }
208
209 if (!presp && !beacon)
210 return RX_CONTINUE;
211
212 if (baselen > skb->len)
213 return RX_DROP_MONITOR;
214
215 ieee802_11_parse_elems(elements, skb->len - baselen, &elems);
216
217 if (elems.ds_params && elems.ds_params_len == 1)
218 freq = ieee80211_channel_to_frequency(elems.ds_params[0],
219 rx_status->band);
220 else
221 freq = rx_status->freq;
222
223 channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq);
224
225 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
226 return RX_DROP_MONITOR;
227
228 bss = ieee80211_bss_info_update(sdata->local, rx_status,
229 mgmt, skb->len, &elems,
230 channel, beacon);
231 if (bss)
232 ieee80211_rx_bss_put(sdata->local, bss);
233
234 if (channel == sdata->local->oper_channel)
235 return RX_CONTINUE;
236
237 dev_kfree_skb(skb);
238 return RX_QUEUED;
239}
240
241/* return false if no more work */
242static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
243{
244 struct cfg80211_scan_request *req = local->scan_req;
245 enum ieee80211_band band;
246 int i, ielen, n_chans;
247
248 do {
249 if (local->hw_scan_band == IEEE80211_NUM_BANDS)
250 return false;
251
252 band = local->hw_scan_band;
253 n_chans = 0;
254 for (i = 0; i < req->n_channels; i++) {
255 if (req->channels[i]->band == band) {
256 local->hw_scan_req->channels[n_chans] =
257 req->channels[i];
258 n_chans++;
259 }
260 }
261
262 local->hw_scan_band++;
263 } while (!n_chans);
264
265 local->hw_scan_req->n_channels = n_chans;
266
267 ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie,
268 req->ie, req->ie_len, band,
269 req->rates[band], 0);
270 local->hw_scan_req->ie_len = ielen;
271 local->hw_scan_req->no_cck = req->no_cck;
272
273 return true;
274}
275
276static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted,
277 bool was_hw_scan)
278{
279 struct ieee80211_local *local = hw_to_local(hw);
280
281 lockdep_assert_held(&local->mtx);
282
283 /*
284 * It's ok to abort a not-yet-running scan (that
285 * we have one at all will be verified by checking
286 * local->scan_req next), but not to complete it
287 * successfully.
288 */
289 if (WARN_ON(!local->scanning && !aborted))
290 aborted = true;
291
292 if (WARN_ON(!local->scan_req))
293 return;
294
295 if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) {
296 int rc = drv_hw_scan(local, local->scan_sdata, local->hw_scan_req);
297 if (rc == 0)
298 return;
299 }
300
301 kfree(local->hw_scan_req);
302 local->hw_scan_req = NULL;
303
304 if (local->scan_req != local->int_scan_req)
305 cfg80211_scan_done(local->scan_req, aborted);
306 local->scan_req = NULL;
307 local->scan_sdata = NULL;
308
309 local->scanning = 0;
310 local->scan_channel = NULL;
311
312 /* Set power back to normal operating levels. */
313 ieee80211_hw_config(local, 0);
314
315 if (!was_hw_scan) {
316 ieee80211_configure_filter(local);
317 drv_sw_scan_complete(local);
318 ieee80211_offchannel_return(local, true);
319 }
320
321 ieee80211_recalc_idle(local);
322
323 ieee80211_mlme_notify_scan_completed(local);
324 ieee80211_ibss_notify_scan_completed(local);
325 ieee80211_mesh_notify_scan_completed(local);
326 ieee80211_queue_work(&local->hw, &local->work_work);
327}
328
329void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
330{
331 struct ieee80211_local *local = hw_to_local(hw);
332
333 trace_api_scan_completed(local, aborted);
334
335 set_bit(SCAN_COMPLETED, &local->scanning);
336 if (aborted)
337 set_bit(SCAN_ABORTED, &local->scanning);
338 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
339}
340EXPORT_SYMBOL(ieee80211_scan_completed);
341
342static int ieee80211_start_sw_scan(struct ieee80211_local *local)
343{
344 /*
345 * Hardware/driver doesn't support hw_scan, so use software
346 * scanning instead. First send a nullfunc frame with power save
347 * bit on so that AP will buffer the frames for us while we are not
348 * listening, then send probe requests to each channel and wait for
349 * the responses. After all channels are scanned, tune back to the
350 * original channel and send a nullfunc frame with power save bit
351 * off to trigger the AP to send us all the buffered frames.
352 *
353 * Note that while local->sw_scanning is true everything else but
354 * nullfunc frames and probe requests will be dropped in
355 * ieee80211_tx_h_check_assoc().
356 */
357 drv_sw_scan_start(local);
358
359 local->leave_oper_channel_time = jiffies;
360 local->next_scan_state = SCAN_DECISION;
361 local->scan_channel_idx = 0;
362
363 ieee80211_offchannel_stop_vifs(local, true);
364
365 ieee80211_configure_filter(local);
366
367 /* We need to set power level at maximum rate for scanning. */
368 ieee80211_hw_config(local, 0);
369
370 ieee80211_queue_delayed_work(&local->hw,
371 &local->scan_work, 0);
372
373 return 0;
374}
375
376static bool ieee80211_can_scan(struct ieee80211_local *local,
377 struct ieee80211_sub_if_data *sdata)
378{
379 if (!list_empty(&local->work_list))
380 return false;
381
382 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
383 sdata->u.mgd.flags & (IEEE80211_STA_BEACON_POLL |
384 IEEE80211_STA_CONNECTION_POLL))
385 return false;
386
387 return true;
388}
389
390void ieee80211_run_deferred_scan(struct ieee80211_local *local)
391{
392 lockdep_assert_held(&local->mtx);
393
394 if (!local->scan_req || local->scanning)
395 return;
396
397 if (!ieee80211_can_scan(local, local->scan_sdata))
398 return;
399
400 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
401 round_jiffies_relative(0));
402}
403
404static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
405 unsigned long *next_delay)
406{
407 int i;
408 struct ieee80211_sub_if_data *sdata = local->scan_sdata;
409 enum ieee80211_band band = local->hw.conf.channel->band;
410
411 for (i = 0; i < local->scan_req->n_ssids; i++)
412 ieee80211_send_probe_req(
413 sdata, NULL,
414 local->scan_req->ssids[i].ssid,
415 local->scan_req->ssids[i].ssid_len,
416 local->scan_req->ie, local->scan_req->ie_len,
417 local->scan_req->rates[band], false,
418 local->scan_req->no_cck);
419
420 /*
421 * After sending probe requests, wait for probe responses
422 * on the channel.
423 */
424 *next_delay = IEEE80211_CHANNEL_TIME;
425 local->next_scan_state = SCAN_DECISION;
426}
427
428static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
429 struct cfg80211_scan_request *req)
430{
431 struct ieee80211_local *local = sdata->local;
432 int rc;
433
434 lockdep_assert_held(&local->mtx);
435
436 if (local->scan_req)
437 return -EBUSY;
438
439 if (!ieee80211_can_scan(local, sdata)) {
440 /* wait for the work to finish/time out */
441 local->scan_req = req;
442 local->scan_sdata = sdata;
443 return 0;
444 }
445
446 if (local->ops->hw_scan) {
447 u8 *ies;
448
449 local->hw_scan_req = kmalloc(
450 sizeof(*local->hw_scan_req) +
451 req->n_channels * sizeof(req->channels[0]) +
452 2 + IEEE80211_MAX_SSID_LEN + local->scan_ies_len +
453 req->ie_len, GFP_KERNEL);
454 if (!local->hw_scan_req)
455 return -ENOMEM;
456
457 local->hw_scan_req->ssids = req->ssids;
458 local->hw_scan_req->n_ssids = req->n_ssids;
459 ies = (u8 *)local->hw_scan_req +
460 sizeof(*local->hw_scan_req) +
461 req->n_channels * sizeof(req->channels[0]);
462 local->hw_scan_req->ie = ies;
463
464 local->hw_scan_band = 0;
465
466 /*
467 * After allocating local->hw_scan_req, we must
468 * go through until ieee80211_prep_hw_scan(), so
469 * anything that might be changed here and leave
470 * this function early must not go after this
471 * allocation.
472 */
473 }
474
475 local->scan_req = req;
476 local->scan_sdata = sdata;
477
478 if (local->ops->hw_scan) {
479 __set_bit(SCAN_HW_SCANNING, &local->scanning);
480 } else if ((req->n_channels == 1) &&
481 (req->channels[0]->center_freq ==
482 local->hw.conf.channel->center_freq)) {
483
484 /* If we are scanning only on the current channel, then
485 * we do not need to stop normal activities
486 */
487 unsigned long next_delay;
488
489 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
490
491 ieee80211_recalc_idle(local);
492
493 /* Notify driver scan is starting, keep order of operations
494 * same as normal software scan, in case that matters. */
495 drv_sw_scan_start(local);
496
497 ieee80211_configure_filter(local); /* accept probe-responses */
498
499 /* We need to ensure power level is at max for scanning. */
500 ieee80211_hw_config(local, 0);
501
502 if ((req->channels[0]->flags &
503 IEEE80211_CHAN_PASSIVE_SCAN) ||
504 !local->scan_req->n_ssids) {
505 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
506 } else {
507 ieee80211_scan_state_send_probe(local, &next_delay);
508 next_delay = IEEE80211_CHANNEL_TIME;
509 }
510
511 /* Now, just wait a bit and we are all done! */
512 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
513 next_delay);
514 return 0;
515 } else {
516 /* Do normal software scan */
517 __set_bit(SCAN_SW_SCANNING, &local->scanning);
518 }
519
520 ieee80211_recalc_idle(local);
521
522 if (local->ops->hw_scan) {
523 WARN_ON(!ieee80211_prep_hw_scan(local));
524 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
525 } else
526 rc = ieee80211_start_sw_scan(local);
527
528 if (rc) {
529 kfree(local->hw_scan_req);
530 local->hw_scan_req = NULL;
531 local->scanning = 0;
532
533 ieee80211_recalc_idle(local);
534
535 local->scan_req = NULL;
536 local->scan_sdata = NULL;
537 }
538
539 return rc;
540}
541
542static unsigned long
543ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
544{
545 /*
546 * TODO: channel switching also consumes quite some time,
547 * add that delay as well to get a better estimation
548 */
549 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN)
550 return IEEE80211_PASSIVE_CHANNEL_TIME;
551 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
552}
553
554static void ieee80211_scan_state_decision(struct ieee80211_local *local,
555 unsigned long *next_delay)
556{
557 bool associated = false;
558 bool tx_empty = true;
559 bool bad_latency;
560 bool listen_int_exceeded;
561 unsigned long min_beacon_int = 0;
562 struct ieee80211_sub_if_data *sdata;
563 struct ieee80211_channel *next_chan;
564
565 /*
566 * check if at least one STA interface is associated,
567 * check if at least one STA interface has pending tx frames
568 * and grab the lowest used beacon interval
569 */
570 mutex_lock(&local->iflist_mtx);
571 list_for_each_entry(sdata, &local->interfaces, list) {
572 if (!ieee80211_sdata_running(sdata))
573 continue;
574
575 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
576 if (sdata->u.mgd.associated) {
577 associated = true;
578
579 if (sdata->vif.bss_conf.beacon_int <
580 min_beacon_int || min_beacon_int == 0)
581 min_beacon_int =
582 sdata->vif.bss_conf.beacon_int;
583
584 if (!qdisc_all_tx_empty(sdata->dev)) {
585 tx_empty = false;
586 break;
587 }
588 }
589 }
590 }
591 mutex_unlock(&local->iflist_mtx);
592
593 next_chan = local->scan_req->channels[local->scan_channel_idx];
594
595 /*
596 * we're currently scanning a different channel, let's
597 * see if we can scan another channel without interfering
598 * with the current traffic situation.
599 *
600 * Since we don't know if the AP has pending frames for us
601 * we can only check for our tx queues and use the current
602 * pm_qos requirements for rx. Hence, if no tx traffic occurs
603 * at all we will scan as many channels in a row as the pm_qos
604 * latency allows us to. Additionally we also check for the
605 * currently negotiated listen interval to prevent losing
606 * frames unnecessarily.
607 *
608 * Otherwise switch back to the operating channel.
609 */
610
611 bad_latency = time_after(jiffies +
612 ieee80211_scan_get_channel_time(next_chan),
613 local->leave_oper_channel_time +
614 usecs_to_jiffies(pm_qos_request(PM_QOS_NETWORK_LATENCY)));
615
616 listen_int_exceeded = time_after(jiffies +
617 ieee80211_scan_get_channel_time(next_chan),
618 local->leave_oper_channel_time +
619 usecs_to_jiffies(min_beacon_int * 1024) *
620 local->hw.conf.listen_interval);
621
622 if (associated && (!tx_empty || bad_latency || listen_int_exceeded))
623 local->next_scan_state = SCAN_SUSPEND;
624 else
625 local->next_scan_state = SCAN_SET_CHANNEL;
626
627 *next_delay = 0;
628}
629
630static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
631 unsigned long *next_delay)
632{
633 int skip;
634 struct ieee80211_channel *chan;
635
636 skip = 0;
637 chan = local->scan_req->channels[local->scan_channel_idx];
638
639 local->scan_channel = chan;
640
641 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
642 skip = 1;
643
644 /* advance state machine to next channel/band */
645 local->scan_channel_idx++;
646
647 if (skip) {
648 /* if we skip this channel return to the decision state */
649 local->next_scan_state = SCAN_DECISION;
650 return;
651 }
652
653 /*
654 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
655 * (which unfortunately doesn't say _why_ step a) is done,
656 * but it waits for the probe delay or until a frame is
657 * received - and the received frame would update the NAV).
658 * For now, we do not support waiting until a frame is
659 * received.
660 *
661 * In any case, it is not necessary for a passive scan.
662 */
663 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN ||
664 !local->scan_req->n_ssids) {
665 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
666 local->next_scan_state = SCAN_DECISION;
667 return;
668 }
669
670 /* active scan, send probes */
671 *next_delay = IEEE80211_PROBE_DELAY;
672 local->next_scan_state = SCAN_SEND_PROBE;
673}
674
675static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
676 unsigned long *next_delay)
677{
678 /* switch back to the operating channel */
679 local->scan_channel = NULL;
680 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
681
682 /*
683 * Re-enable vifs and beaconing. Leave PS
684 * in off-channel state..will put that back
685 * on-channel at the end of scanning.
686 */
687 ieee80211_offchannel_return(local, false);
688
689 *next_delay = HZ / 5;
690 /* afterwards, resume scan & go to next channel */
691 local->next_scan_state = SCAN_RESUME;
692}
693
694static void ieee80211_scan_state_resume(struct ieee80211_local *local,
695 unsigned long *next_delay)
696{
697 /* PS already is in off-channel mode */
698 ieee80211_offchannel_stop_vifs(local, false);
699
700 if (local->ops->flush) {
701 drv_flush(local, false);
702 *next_delay = 0;
703 } else
704 *next_delay = HZ / 10;
705
706 /* remember when we left the operating channel */
707 local->leave_oper_channel_time = jiffies;
708
709 /* advance to the next channel to be scanned */
710 local->next_scan_state = SCAN_SET_CHANNEL;
711}
712
713void ieee80211_scan_work(struct work_struct *work)
714{
715 struct ieee80211_local *local =
716 container_of(work, struct ieee80211_local, scan_work.work);
717 struct ieee80211_sub_if_data *sdata;
718 unsigned long next_delay = 0;
719 bool aborted, hw_scan;
720
721 mutex_lock(&local->mtx);
722
723 sdata = local->scan_sdata;
724
725 /* When scanning on-channel, the first-callback means completed. */
726 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
727 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
728 goto out_complete;
729 }
730
731 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
732 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
733 goto out_complete;
734 }
735
736 if (!sdata || !local->scan_req)
737 goto out;
738
739 if (local->scan_req && !local->scanning) {
740 struct cfg80211_scan_request *req = local->scan_req;
741 int rc;
742
743 local->scan_req = NULL;
744 local->scan_sdata = NULL;
745
746 rc = __ieee80211_start_scan(sdata, req);
747 if (rc) {
748 /* need to complete scan in cfg80211 */
749 local->scan_req = req;
750 aborted = true;
751 goto out_complete;
752 } else
753 goto out;
754 }
755
756 /*
757 * Avoid re-scheduling when the sdata is going away.
758 */
759 if (!ieee80211_sdata_running(sdata)) {
760 aborted = true;
761 goto out_complete;
762 }
763
764 /*
765 * as long as no delay is required advance immediately
766 * without scheduling a new work
767 */
768 do {
769 if (!ieee80211_sdata_running(sdata)) {
770 aborted = true;
771 goto out_complete;
772 }
773
774 switch (local->next_scan_state) {
775 case SCAN_DECISION:
776 /* if no more bands/channels left, complete scan */
777 if (local->scan_channel_idx >= local->scan_req->n_channels) {
778 aborted = false;
779 goto out_complete;
780 }
781 ieee80211_scan_state_decision(local, &next_delay);
782 break;
783 case SCAN_SET_CHANNEL:
784 ieee80211_scan_state_set_channel(local, &next_delay);
785 break;
786 case SCAN_SEND_PROBE:
787 ieee80211_scan_state_send_probe(local, &next_delay);
788 break;
789 case SCAN_SUSPEND:
790 ieee80211_scan_state_suspend(local, &next_delay);
791 break;
792 case SCAN_RESUME:
793 ieee80211_scan_state_resume(local, &next_delay);
794 break;
795 }
796 } while (next_delay == 0);
797
798 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
799 goto out;
800
801out_complete:
802 hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
803 __ieee80211_scan_completed(&local->hw, aborted, hw_scan);
804out:
805 mutex_unlock(&local->mtx);
806}
807
808int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
809 struct cfg80211_scan_request *req)
810{
811 int res;
812
813 mutex_lock(&sdata->local->mtx);
814 res = __ieee80211_start_scan(sdata, req);
815 mutex_unlock(&sdata->local->mtx);
816
817 return res;
818}
819
820int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata,
821 const u8 *ssid, u8 ssid_len,
822 struct ieee80211_channel *chan)
823{
824 struct ieee80211_local *local = sdata->local;
825 int ret = -EBUSY;
826 enum ieee80211_band band;
827
828 mutex_lock(&local->mtx);
829
830 /* busy scanning */
831 if (local->scan_req)
832 goto unlock;
833
834 /* fill internal scan request */
835 if (!chan) {
836 int i, nchan = 0;
837
838 for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
839 if (!local->hw.wiphy->bands[band])
840 continue;
841 for (i = 0;
842 i < local->hw.wiphy->bands[band]->n_channels;
843 i++) {
844 local->int_scan_req->channels[nchan] =
845 &local->hw.wiphy->bands[band]->channels[i];
846 nchan++;
847 }
848 }
849
850 local->int_scan_req->n_channels = nchan;
851 } else {
852 local->int_scan_req->channels[0] = chan;
853 local->int_scan_req->n_channels = 1;
854 }
855
856 local->int_scan_req->ssids = &local->scan_ssid;
857 local->int_scan_req->n_ssids = 1;
858 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
859 local->int_scan_req->ssids[0].ssid_len = ssid_len;
860
861 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
862 unlock:
863 mutex_unlock(&local->mtx);
864 return ret;
865}
866
867/*
868 * Only call this function when a scan can't be queued -- under RTNL.
869 */
870void ieee80211_scan_cancel(struct ieee80211_local *local)
871{
872 /*
873 * We are canceling software scan, or deferred scan that was not
874 * yet really started (see __ieee80211_start_scan ).
875 *
876 * Regarding hardware scan:
877 * - we can not call __ieee80211_scan_completed() as when
878 * SCAN_HW_SCANNING bit is set this function change
879 * local->hw_scan_req to operate on 5G band, what race with
880 * driver which can use local->hw_scan_req
881 *
882 * - we can not cancel scan_work since driver can schedule it
883 * by ieee80211_scan_completed(..., true) to finish scan
884 *
885 * Hence we only call the cancel_hw_scan() callback, but the low-level
886 * driver is still responsible for calling ieee80211_scan_completed()
887 * after the scan was completed/aborted.
888 */
889
890 mutex_lock(&local->mtx);
891 if (!local->scan_req)
892 goto out;
893
894 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
895 if (local->ops->cancel_hw_scan)
896 drv_cancel_hw_scan(local, local->scan_sdata);
897 goto out;
898 }
899
900 /*
901 * If the work is currently running, it must be blocked on
902 * the mutex, but we'll set scan_sdata = NULL and it'll
903 * simply exit once it acquires the mutex.
904 */
905 cancel_delayed_work(&local->scan_work);
906 /* and clean up */
907 __ieee80211_scan_completed(&local->hw, true, false);
908out:
909 mutex_unlock(&local->mtx);
910}
911
912int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
913 struct cfg80211_sched_scan_request *req)
914{
915 struct ieee80211_local *local = sdata->local;
916 int ret, i;
917
918 mutex_lock(&sdata->local->mtx);
919
920 if (local->sched_scanning) {
921 ret = -EBUSY;
922 goto out;
923 }
924
925 if (!local->ops->sched_scan_start) {
926 ret = -ENOTSUPP;
927 goto out;
928 }
929
930 for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
931 local->sched_scan_ies.ie[i] = kzalloc(2 +
932 IEEE80211_MAX_SSID_LEN +
933 local->scan_ies_len +
934 req->ie_len,
935 GFP_KERNEL);
936 if (!local->sched_scan_ies.ie[i]) {
937 ret = -ENOMEM;
938 goto out_free;
939 }
940
941 local->sched_scan_ies.len[i] =
942 ieee80211_build_preq_ies(local,
943 local->sched_scan_ies.ie[i],
944 req->ie, req->ie_len, i,
945 (u32) -1, 0);
946 }
947
948 ret = drv_sched_scan_start(local, sdata, req,
949 &local->sched_scan_ies);
950 if (ret == 0) {
951 local->sched_scanning = true;
952 goto out;
953 }
954
955out_free:
956 while (i > 0)
957 kfree(local->sched_scan_ies.ie[--i]);
958out:
959 mutex_unlock(&sdata->local->mtx);
960 return ret;
961}
962
963int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata)
964{
965 struct ieee80211_local *local = sdata->local;
966 int ret = 0, i;
967
968 mutex_lock(&sdata->local->mtx);
969
970 if (!local->ops->sched_scan_stop) {
971 ret = -ENOTSUPP;
972 goto out;
973 }
974
975 if (local->sched_scanning) {
976 for (i = 0; i < IEEE80211_NUM_BANDS; i++)
977 kfree(local->sched_scan_ies.ie[i]);
978
979 drv_sched_scan_stop(local, sdata);
980 local->sched_scanning = false;
981 }
982out:
983 mutex_unlock(&sdata->local->mtx);
984
985 return ret;
986}
987
988void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
989{
990 struct ieee80211_local *local = hw_to_local(hw);
991
992 trace_api_sched_scan_results(local);
993
994 cfg80211_sched_scan_results(hw->wiphy);
995}
996EXPORT_SYMBOL(ieee80211_sched_scan_results);
997
998void ieee80211_sched_scan_stopped_work(struct work_struct *work)
999{
1000 struct ieee80211_local *local =
1001 container_of(work, struct ieee80211_local,
1002 sched_scan_stopped_work);
1003 int i;
1004
1005 mutex_lock(&local->mtx);
1006
1007 if (!local->sched_scanning) {
1008 mutex_unlock(&local->mtx);
1009 return;
1010 }
1011
1012 for (i = 0; i < IEEE80211_NUM_BANDS; i++)
1013 kfree(local->sched_scan_ies.ie[i]);
1014
1015 local->sched_scanning = false;
1016
1017 mutex_unlock(&local->mtx);
1018
1019 cfg80211_sched_scan_stopped(local->hw.wiphy);
1020}
1021
1022void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1023{
1024 struct ieee80211_local *local = hw_to_local(hw);
1025
1026 trace_api_sched_scan_stopped(local);
1027
1028 ieee80211_queue_work(&local->hw, &local->sched_scan_stopped_work);
1029}
1030EXPORT_SYMBOL(ieee80211_sched_scan_stopped);