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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Scanning implementation
4 *
5 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
6 * Copyright 2004, Instant802 Networks, Inc.
7 * Copyright 2005, Devicescape Software, Inc.
8 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
9 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
10 * Copyright 2013-2015 Intel Mobile Communications GmbH
11 * Copyright 2016-2017 Intel Deutschland GmbH
12 * Copyright (C) 2018-2020 Intel Corporation
13 */
14
15#include <linux/if_arp.h>
16#include <linux/etherdevice.h>
17#include <linux/rtnetlink.h>
18#include <net/sch_generic.h>
19#include <linux/slab.h>
20#include <linux/export.h>
21#include <linux/random.h>
22#include <net/mac80211.h>
23
24#include "ieee80211_i.h"
25#include "driver-ops.h"
26#include "mesh.h"
27
28#define IEEE80211_PROBE_DELAY (HZ / 33)
29#define IEEE80211_CHANNEL_TIME (HZ / 33)
30#define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
31
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
58static void
59ieee80211_update_bss_from_elems(struct ieee80211_local *local,
60 struct ieee80211_bss *bss,
61 struct ieee802_11_elems *elems,
62 struct ieee80211_rx_status *rx_status,
63 bool beacon)
64{
65 int clen, srlen;
66
67 if (beacon)
68 bss->device_ts_beacon = rx_status->device_timestamp;
69 else
70 bss->device_ts_presp = rx_status->device_timestamp;
71
72 if (elems->parse_error) {
73 if (beacon)
74 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
75 else
76 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
77 } else {
78 if (beacon)
79 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
80 else
81 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
82 }
83
84 /* save the ERP value so that it is available at association time */
85 if (elems->erp_info && (!elems->parse_error ||
86 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
87 bss->erp_value = elems->erp_info[0];
88 bss->has_erp_value = true;
89 if (!elems->parse_error)
90 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
91 }
92
93 /* replace old supported rates if we get new values */
94 if (!elems->parse_error ||
95 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
96 srlen = 0;
97 if (elems->supp_rates) {
98 clen = IEEE80211_MAX_SUPP_RATES;
99 if (clen > elems->supp_rates_len)
100 clen = elems->supp_rates_len;
101 memcpy(bss->supp_rates, elems->supp_rates, clen);
102 srlen += clen;
103 }
104 if (elems->ext_supp_rates) {
105 clen = IEEE80211_MAX_SUPP_RATES - srlen;
106 if (clen > elems->ext_supp_rates_len)
107 clen = elems->ext_supp_rates_len;
108 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
109 clen);
110 srlen += clen;
111 }
112 if (srlen) {
113 bss->supp_rates_len = srlen;
114 if (!elems->parse_error)
115 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
116 }
117 }
118
119 if (!elems->parse_error ||
120 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
121 bss->wmm_used = elems->wmm_param || elems->wmm_info;
122 bss->uapsd_supported = is_uapsd_supported(elems);
123 if (!elems->parse_error)
124 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
125 }
126
127 if (beacon) {
128 struct ieee80211_supported_band *sband =
129 local->hw.wiphy->bands[rx_status->band];
130 if (!(rx_status->encoding == RX_ENC_HT) &&
131 !(rx_status->encoding == RX_ENC_VHT))
132 bss->beacon_rate =
133 &sband->bitrates[rx_status->rate_idx];
134 }
135
136 if (elems->vht_cap_elem)
137 bss->vht_cap_info =
138 le32_to_cpu(elems->vht_cap_elem->vht_cap_info);
139 else
140 bss->vht_cap_info = 0;
141}
142
143struct ieee80211_bss *
144ieee80211_bss_info_update(struct ieee80211_local *local,
145 struct ieee80211_rx_status *rx_status,
146 struct ieee80211_mgmt *mgmt, size_t len,
147 struct ieee80211_channel *channel)
148{
149 bool beacon = ieee80211_is_beacon(mgmt->frame_control) ||
150 ieee80211_is_s1g_beacon(mgmt->frame_control);
151 struct cfg80211_bss *cbss, *non_tx_cbss;
152 struct ieee80211_bss *bss, *non_tx_bss;
153 struct cfg80211_inform_bss bss_meta = {
154 .boottime_ns = rx_status->boottime_ns,
155 };
156 bool signal_valid;
157 struct ieee80211_sub_if_data *scan_sdata;
158 struct ieee802_11_elems elems;
159 size_t baselen;
160 u8 *elements;
161
162 if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
163 bss_meta.signal = 0; /* invalid signal indication */
164 else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
165 bss_meta.signal = rx_status->signal * 100;
166 else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
167 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
168
169 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
170 if (rx_status->bw == RATE_INFO_BW_5)
171 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
172 else if (rx_status->bw == RATE_INFO_BW_10)
173 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
174
175 bss_meta.chan = channel;
176
177 rcu_read_lock();
178 scan_sdata = rcu_dereference(local->scan_sdata);
179 if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
180 scan_sdata->vif.bss_conf.assoc &&
181 ieee80211_have_rx_timestamp(rx_status)) {
182 bss_meta.parent_tsf =
183 ieee80211_calculate_rx_timestamp(local, rx_status,
184 len + FCS_LEN, 24);
185 ether_addr_copy(bss_meta.parent_bssid,
186 scan_sdata->vif.bss_conf.bssid);
187 }
188 rcu_read_unlock();
189
190 cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
191 mgmt, len, GFP_ATOMIC);
192 if (!cbss)
193 return NULL;
194
195 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
196 elements = mgmt->u.probe_resp.variable;
197 baselen = offsetof(struct ieee80211_mgmt,
198 u.probe_resp.variable);
199 } else if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
200 struct ieee80211_ext *ext = (void *) mgmt;
201
202 baselen = offsetof(struct ieee80211_ext, u.s1g_beacon.variable);
203 elements = ext->u.s1g_beacon.variable;
204 } else {
205 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
206 elements = mgmt->u.beacon.variable;
207 }
208
209 if (baselen > len)
210 return NULL;
211
212 ieee802_11_parse_elems(elements, len - baselen, false, &elems,
213 mgmt->bssid, cbss->bssid);
214
215 /* In case the signal is invalid update the status */
216 signal_valid = channel == cbss->channel;
217 if (!signal_valid)
218 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
219
220 bss = (void *)cbss->priv;
221 ieee80211_update_bss_from_elems(local, bss, &elems, rx_status, beacon);
222
223 list_for_each_entry(non_tx_cbss, &cbss->nontrans_list, nontrans_list) {
224 non_tx_bss = (void *)non_tx_cbss->priv;
225
226 ieee80211_update_bss_from_elems(local, non_tx_bss, &elems,
227 rx_status, beacon);
228 }
229
230 return bss;
231}
232
233static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
234 u32 scan_flags, const u8 *da)
235{
236 if (!sdata)
237 return false;
238 /* accept broadcast for OCE */
239 if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
240 is_broadcast_ether_addr(da))
241 return true;
242 if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
243 return true;
244 return ether_addr_equal(da, sdata->vif.addr);
245}
246
247void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
248{
249 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
250 struct ieee80211_sub_if_data *sdata1, *sdata2;
251 struct ieee80211_mgmt *mgmt = (void *)skb->data;
252 struct ieee80211_bss *bss;
253 struct ieee80211_channel *channel;
254 size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
255 u.probe_resp.variable);
256
257 if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
258 !ieee80211_is_beacon(mgmt->frame_control) &&
259 !ieee80211_is_s1g_beacon(mgmt->frame_control))
260 return;
261
262 if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
263 if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
264 min_hdr_len = offsetof(struct ieee80211_ext,
265 u.s1g_short_beacon.variable);
266 else
267 min_hdr_len = offsetof(struct ieee80211_ext,
268 u.s1g_beacon);
269 }
270
271 if (skb->len < min_hdr_len)
272 return;
273
274 sdata1 = rcu_dereference(local->scan_sdata);
275 sdata2 = rcu_dereference(local->sched_scan_sdata);
276
277 if (likely(!sdata1 && !sdata2))
278 return;
279
280 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
281 struct cfg80211_scan_request *scan_req;
282 struct cfg80211_sched_scan_request *sched_scan_req;
283 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
284
285 scan_req = rcu_dereference(local->scan_req);
286 sched_scan_req = rcu_dereference(local->sched_scan_req);
287
288 if (scan_req)
289 scan_req_flags = scan_req->flags;
290
291 if (sched_scan_req)
292 sched_scan_req_flags = sched_scan_req->flags;
293
294 /* ignore ProbeResp to foreign address or non-bcast (OCE)
295 * unless scanning with randomised address
296 */
297 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
298 mgmt->da) &&
299 !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
300 mgmt->da))
301 return;
302 }
303
304 channel = ieee80211_get_channel_khz(local->hw.wiphy,
305 ieee80211_rx_status_to_khz(rx_status));
306
307 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
308 return;
309
310 bss = ieee80211_bss_info_update(local, rx_status,
311 mgmt, skb->len,
312 channel);
313 if (bss)
314 ieee80211_rx_bss_put(local, bss);
315}
316
317static void
318ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
319 enum nl80211_bss_scan_width scan_width)
320{
321 memset(chandef, 0, sizeof(*chandef));
322 switch (scan_width) {
323 case NL80211_BSS_CHAN_WIDTH_5:
324 chandef->width = NL80211_CHAN_WIDTH_5;
325 break;
326 case NL80211_BSS_CHAN_WIDTH_10:
327 chandef->width = NL80211_CHAN_WIDTH_10;
328 break;
329 default:
330 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
331 break;
332 }
333}
334
335/* return false if no more work */
336static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
337{
338 struct ieee80211_local *local = sdata->local;
339 struct cfg80211_scan_request *req;
340 struct cfg80211_chan_def chandef;
341 u8 bands_used = 0;
342 int i, ielen, n_chans;
343 u32 flags = 0;
344
345 req = rcu_dereference_protected(local->scan_req,
346 lockdep_is_held(&local->mtx));
347
348 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
349 return false;
350
351 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
352 for (i = 0; i < req->n_channels; i++) {
353 local->hw_scan_req->req.channels[i] = req->channels[i];
354 bands_used |= BIT(req->channels[i]->band);
355 }
356
357 n_chans = req->n_channels;
358 } else {
359 do {
360 if (local->hw_scan_band == NUM_NL80211_BANDS)
361 return false;
362
363 n_chans = 0;
364
365 for (i = 0; i < req->n_channels; i++) {
366 if (req->channels[i]->band !=
367 local->hw_scan_band)
368 continue;
369 local->hw_scan_req->req.channels[n_chans] =
370 req->channels[i];
371 n_chans++;
372 bands_used |= BIT(req->channels[i]->band);
373 }
374
375 local->hw_scan_band++;
376 } while (!n_chans);
377 }
378
379 local->hw_scan_req->req.n_channels = n_chans;
380 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
381
382 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
383 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
384
385 ielen = ieee80211_build_preq_ies(sdata,
386 (u8 *)local->hw_scan_req->req.ie,
387 local->hw_scan_ies_bufsize,
388 &local->hw_scan_req->ies,
389 req->ie, req->ie_len,
390 bands_used, req->rates, &chandef,
391 flags);
392 local->hw_scan_req->req.ie_len = ielen;
393 local->hw_scan_req->req.no_cck = req->no_cck;
394 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
395 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
396 req->mac_addr_mask);
397 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
398
399 return true;
400}
401
402static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
403{
404 struct ieee80211_local *local = hw_to_local(hw);
405 bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
406 bool was_scanning = local->scanning;
407 struct cfg80211_scan_request *scan_req;
408 struct ieee80211_sub_if_data *scan_sdata;
409 struct ieee80211_sub_if_data *sdata;
410
411 lockdep_assert_held(&local->mtx);
412
413 /*
414 * It's ok to abort a not-yet-running scan (that
415 * we have one at all will be verified by checking
416 * local->scan_req next), but not to complete it
417 * successfully.
418 */
419 if (WARN_ON(!local->scanning && !aborted))
420 aborted = true;
421
422 if (WARN_ON(!local->scan_req))
423 return;
424
425 scan_sdata = rcu_dereference_protected(local->scan_sdata,
426 lockdep_is_held(&local->mtx));
427
428 if (hw_scan && !aborted &&
429 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
430 ieee80211_prep_hw_scan(scan_sdata)) {
431 int rc;
432
433 rc = drv_hw_scan(local,
434 rcu_dereference_protected(local->scan_sdata,
435 lockdep_is_held(&local->mtx)),
436 local->hw_scan_req);
437
438 if (rc == 0)
439 return;
440
441 /* HW scan failed and is going to be reported as aborted,
442 * so clear old scan info.
443 */
444 memset(&local->scan_info, 0, sizeof(local->scan_info));
445 aborted = true;
446 }
447
448 kfree(local->hw_scan_req);
449 local->hw_scan_req = NULL;
450
451 scan_req = rcu_dereference_protected(local->scan_req,
452 lockdep_is_held(&local->mtx));
453
454 if (scan_req != local->int_scan_req) {
455 local->scan_info.aborted = aborted;
456 cfg80211_scan_done(scan_req, &local->scan_info);
457 }
458 RCU_INIT_POINTER(local->scan_req, NULL);
459 RCU_INIT_POINTER(local->scan_sdata, NULL);
460
461 local->scanning = 0;
462 local->scan_chandef.chan = NULL;
463
464 /* Set power back to normal operating levels. */
465 ieee80211_hw_config(local, 0);
466
467 if (!hw_scan) {
468 ieee80211_configure_filter(local);
469 drv_sw_scan_complete(local, scan_sdata);
470 ieee80211_offchannel_return(local);
471 }
472
473 ieee80211_recalc_idle(local);
474
475 ieee80211_mlme_notify_scan_completed(local);
476 ieee80211_ibss_notify_scan_completed(local);
477
478 /* Requeue all the work that might have been ignored while
479 * the scan was in progress; if there was none this will
480 * just be a no-op for the particular interface.
481 */
482 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
483 if (ieee80211_sdata_running(sdata))
484 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
485 }
486
487 if (was_scanning)
488 ieee80211_start_next_roc(local);
489}
490
491void ieee80211_scan_completed(struct ieee80211_hw *hw,
492 struct cfg80211_scan_info *info)
493{
494 struct ieee80211_local *local = hw_to_local(hw);
495
496 trace_api_scan_completed(local, info->aborted);
497
498 set_bit(SCAN_COMPLETED, &local->scanning);
499 if (info->aborted)
500 set_bit(SCAN_ABORTED, &local->scanning);
501
502 memcpy(&local->scan_info, info, sizeof(*info));
503
504 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
505}
506EXPORT_SYMBOL(ieee80211_scan_completed);
507
508static int ieee80211_start_sw_scan(struct ieee80211_local *local,
509 struct ieee80211_sub_if_data *sdata)
510{
511 /* Software scan is not supported in multi-channel cases */
512 if (local->use_chanctx)
513 return -EOPNOTSUPP;
514
515 /*
516 * Hardware/driver doesn't support hw_scan, so use software
517 * scanning instead. First send a nullfunc frame with power save
518 * bit on so that AP will buffer the frames for us while we are not
519 * listening, then send probe requests to each channel and wait for
520 * the responses. After all channels are scanned, tune back to the
521 * original channel and send a nullfunc frame with power save bit
522 * off to trigger the AP to send us all the buffered frames.
523 *
524 * Note that while local->sw_scanning is true everything else but
525 * nullfunc frames and probe requests will be dropped in
526 * ieee80211_tx_h_check_assoc().
527 */
528 drv_sw_scan_start(local, sdata, local->scan_addr);
529
530 local->leave_oper_channel_time = jiffies;
531 local->next_scan_state = SCAN_DECISION;
532 local->scan_channel_idx = 0;
533
534 ieee80211_offchannel_stop_vifs(local);
535
536 /* ensure nullfunc is transmitted before leaving operating channel */
537 ieee80211_flush_queues(local, NULL, false);
538
539 ieee80211_configure_filter(local);
540
541 /* We need to set power level at maximum rate for scanning. */
542 ieee80211_hw_config(local, 0);
543
544 ieee80211_queue_delayed_work(&local->hw,
545 &local->scan_work, 0);
546
547 return 0;
548}
549
550static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
551{
552 struct ieee80211_local *local = sdata->local;
553 struct ieee80211_sub_if_data *sdata_iter;
554
555 if (!ieee80211_is_radar_required(local))
556 return true;
557
558 if (!regulatory_pre_cac_allowed(local->hw.wiphy))
559 return false;
560
561 mutex_lock(&local->iflist_mtx);
562 list_for_each_entry(sdata_iter, &local->interfaces, list) {
563 if (sdata_iter->wdev.cac_started) {
564 mutex_unlock(&local->iflist_mtx);
565 return false;
566 }
567 }
568 mutex_unlock(&local->iflist_mtx);
569
570 return true;
571}
572
573static bool ieee80211_can_scan(struct ieee80211_local *local,
574 struct ieee80211_sub_if_data *sdata)
575{
576 if (!__ieee80211_can_leave_ch(sdata))
577 return false;
578
579 if (!list_empty(&local->roc_list))
580 return false;
581
582 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
583 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
584 return false;
585
586 return true;
587}
588
589void ieee80211_run_deferred_scan(struct ieee80211_local *local)
590{
591 lockdep_assert_held(&local->mtx);
592
593 if (!local->scan_req || local->scanning)
594 return;
595
596 if (!ieee80211_can_scan(local,
597 rcu_dereference_protected(
598 local->scan_sdata,
599 lockdep_is_held(&local->mtx))))
600 return;
601
602 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
603 round_jiffies_relative(0));
604}
605
606static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
607 const u8 *src, const u8 *dst,
608 const u8 *ssid, size_t ssid_len,
609 const u8 *ie, size_t ie_len,
610 u32 ratemask, u32 flags, u32 tx_flags,
611 struct ieee80211_channel *channel)
612{
613 struct sk_buff *skb;
614
615 skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
616 ssid, ssid_len,
617 ie, ie_len, flags);
618
619 if (skb) {
620 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
621 struct ieee80211_hdr *hdr = (void *)skb->data;
622 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
623 u16 sn = get_random_u32();
624
625 info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
626 hdr->seq_ctrl =
627 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
628 }
629 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
630 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
631 }
632}
633
634static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
635 unsigned long *next_delay)
636{
637 int i;
638 struct ieee80211_sub_if_data *sdata;
639 struct cfg80211_scan_request *scan_req;
640 enum nl80211_band band = local->hw.conf.chandef.chan->band;
641 u32 flags = 0, tx_flags;
642
643 scan_req = rcu_dereference_protected(local->scan_req,
644 lockdep_is_held(&local->mtx));
645
646 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
647 if (scan_req->no_cck)
648 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
649 if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
650 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
651 if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
652 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
653
654 sdata = rcu_dereference_protected(local->scan_sdata,
655 lockdep_is_held(&local->mtx));
656
657 for (i = 0; i < scan_req->n_ssids; i++)
658 ieee80211_send_scan_probe_req(
659 sdata, local->scan_addr, scan_req->bssid,
660 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
661 scan_req->ie, scan_req->ie_len,
662 scan_req->rates[band], flags,
663 tx_flags, local->hw.conf.chandef.chan);
664
665 /*
666 * After sending probe requests, wait for probe responses
667 * on the channel.
668 */
669 *next_delay = IEEE80211_CHANNEL_TIME;
670 local->next_scan_state = SCAN_DECISION;
671}
672
673static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
674 struct cfg80211_scan_request *req)
675{
676 struct ieee80211_local *local = sdata->local;
677 bool hw_scan = local->ops->hw_scan;
678 int rc;
679
680 lockdep_assert_held(&local->mtx);
681
682 if (local->scan_req)
683 return -EBUSY;
684
685 if (!__ieee80211_can_leave_ch(sdata))
686 return -EBUSY;
687
688 if (!ieee80211_can_scan(local, sdata)) {
689 /* wait for the work to finish/time out */
690 rcu_assign_pointer(local->scan_req, req);
691 rcu_assign_pointer(local->scan_sdata, sdata);
692 return 0;
693 }
694
695 again:
696 if (hw_scan) {
697 u8 *ies;
698
699 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
700
701 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
702 int i, n_bands = 0;
703 u8 bands_counted = 0;
704
705 for (i = 0; i < req->n_channels; i++) {
706 if (bands_counted & BIT(req->channels[i]->band))
707 continue;
708 bands_counted |= BIT(req->channels[i]->band);
709 n_bands++;
710 }
711
712 local->hw_scan_ies_bufsize *= n_bands;
713 }
714
715 local->hw_scan_req = kmalloc(
716 sizeof(*local->hw_scan_req) +
717 req->n_channels * sizeof(req->channels[0]) +
718 local->hw_scan_ies_bufsize, GFP_KERNEL);
719 if (!local->hw_scan_req)
720 return -ENOMEM;
721
722 local->hw_scan_req->req.ssids = req->ssids;
723 local->hw_scan_req->req.n_ssids = req->n_ssids;
724 ies = (u8 *)local->hw_scan_req +
725 sizeof(*local->hw_scan_req) +
726 req->n_channels * sizeof(req->channels[0]);
727 local->hw_scan_req->req.ie = ies;
728 local->hw_scan_req->req.flags = req->flags;
729 eth_broadcast_addr(local->hw_scan_req->req.bssid);
730 local->hw_scan_req->req.duration = req->duration;
731 local->hw_scan_req->req.duration_mandatory =
732 req->duration_mandatory;
733
734 local->hw_scan_band = 0;
735 local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
736 local->hw_scan_req->req.scan_6ghz_params =
737 req->scan_6ghz_params;
738 local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
739
740 /*
741 * After allocating local->hw_scan_req, we must
742 * go through until ieee80211_prep_hw_scan(), so
743 * anything that might be changed here and leave
744 * this function early must not go after this
745 * allocation.
746 */
747 }
748
749 rcu_assign_pointer(local->scan_req, req);
750 rcu_assign_pointer(local->scan_sdata, sdata);
751
752 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
753 get_random_mask_addr(local->scan_addr,
754 req->mac_addr,
755 req->mac_addr_mask);
756 else
757 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
758
759 if (hw_scan) {
760 __set_bit(SCAN_HW_SCANNING, &local->scanning);
761 } else if ((req->n_channels == 1) &&
762 (req->channels[0] == local->_oper_chandef.chan)) {
763 /*
764 * If we are scanning only on the operating channel
765 * then we do not need to stop normal activities
766 */
767 unsigned long next_delay;
768
769 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
770
771 ieee80211_recalc_idle(local);
772
773 /* Notify driver scan is starting, keep order of operations
774 * same as normal software scan, in case that matters. */
775 drv_sw_scan_start(local, sdata, local->scan_addr);
776
777 ieee80211_configure_filter(local); /* accept probe-responses */
778
779 /* We need to ensure power level is at max for scanning. */
780 ieee80211_hw_config(local, 0);
781
782 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
783 IEEE80211_CHAN_RADAR)) ||
784 !req->n_ssids) {
785 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
786 } else {
787 ieee80211_scan_state_send_probe(local, &next_delay);
788 next_delay = IEEE80211_CHANNEL_TIME;
789 }
790
791 /* Now, just wait a bit and we are all done! */
792 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
793 next_delay);
794 return 0;
795 } else {
796 /* Do normal software scan */
797 __set_bit(SCAN_SW_SCANNING, &local->scanning);
798 }
799
800 ieee80211_recalc_idle(local);
801
802 if (hw_scan) {
803 WARN_ON(!ieee80211_prep_hw_scan(sdata));
804 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
805 } else {
806 rc = ieee80211_start_sw_scan(local, sdata);
807 }
808
809 if (rc) {
810 kfree(local->hw_scan_req);
811 local->hw_scan_req = NULL;
812 local->scanning = 0;
813
814 ieee80211_recalc_idle(local);
815
816 local->scan_req = NULL;
817 RCU_INIT_POINTER(local->scan_sdata, NULL);
818 }
819
820 if (hw_scan && rc == 1) {
821 /*
822 * we can't fall back to software for P2P-GO
823 * as it must update NoA etc.
824 */
825 if (ieee80211_vif_type_p2p(&sdata->vif) ==
826 NL80211_IFTYPE_P2P_GO)
827 return -EOPNOTSUPP;
828 hw_scan = false;
829 goto again;
830 }
831
832 return rc;
833}
834
835static unsigned long
836ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
837{
838 /*
839 * TODO: channel switching also consumes quite some time,
840 * add that delay as well to get a better estimation
841 */
842 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
843 return IEEE80211_PASSIVE_CHANNEL_TIME;
844 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
845}
846
847static void ieee80211_scan_state_decision(struct ieee80211_local *local,
848 unsigned long *next_delay)
849{
850 bool associated = false;
851 bool tx_empty = true;
852 bool bad_latency;
853 struct ieee80211_sub_if_data *sdata;
854 struct ieee80211_channel *next_chan;
855 enum mac80211_scan_state next_scan_state;
856 struct cfg80211_scan_request *scan_req;
857
858 /*
859 * check if at least one STA interface is associated,
860 * check if at least one STA interface has pending tx frames
861 * and grab the lowest used beacon interval
862 */
863 mutex_lock(&local->iflist_mtx);
864 list_for_each_entry(sdata, &local->interfaces, list) {
865 if (!ieee80211_sdata_running(sdata))
866 continue;
867
868 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
869 if (sdata->u.mgd.associated) {
870 associated = true;
871
872 if (!qdisc_all_tx_empty(sdata->dev)) {
873 tx_empty = false;
874 break;
875 }
876 }
877 }
878 }
879 mutex_unlock(&local->iflist_mtx);
880
881 scan_req = rcu_dereference_protected(local->scan_req,
882 lockdep_is_held(&local->mtx));
883
884 next_chan = scan_req->channels[local->scan_channel_idx];
885
886 /*
887 * we're currently scanning a different channel, let's
888 * see if we can scan another channel without interfering
889 * with the current traffic situation.
890 *
891 * Keep good latency, do not stay off-channel more than 125 ms.
892 */
893
894 bad_latency = time_after(jiffies +
895 ieee80211_scan_get_channel_time(next_chan),
896 local->leave_oper_channel_time + HZ / 8);
897
898 if (associated && !tx_empty) {
899 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
900 next_scan_state = SCAN_ABORT;
901 else
902 next_scan_state = SCAN_SUSPEND;
903 } else if (associated && bad_latency) {
904 next_scan_state = SCAN_SUSPEND;
905 } else {
906 next_scan_state = SCAN_SET_CHANNEL;
907 }
908
909 local->next_scan_state = next_scan_state;
910
911 *next_delay = 0;
912}
913
914static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
915 unsigned long *next_delay)
916{
917 int skip;
918 struct ieee80211_channel *chan;
919 enum nl80211_bss_scan_width oper_scan_width;
920 struct cfg80211_scan_request *scan_req;
921
922 scan_req = rcu_dereference_protected(local->scan_req,
923 lockdep_is_held(&local->mtx));
924
925 skip = 0;
926 chan = scan_req->channels[local->scan_channel_idx];
927
928 local->scan_chandef.chan = chan;
929 local->scan_chandef.center_freq1 = chan->center_freq;
930 local->scan_chandef.freq1_offset = chan->freq_offset;
931 local->scan_chandef.center_freq2 = 0;
932
933 /* For scanning on the S1G band, ignore scan_width (which is constant
934 * across all channels) for now since channel width is specific to each
935 * channel. Detect the required channel width here and likely revisit
936 * later. Maybe scan_width could be used to build the channel scan list?
937 */
938 if (chan->band == NL80211_BAND_S1GHZ) {
939 local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
940 goto set_channel;
941 }
942
943 switch (scan_req->scan_width) {
944 case NL80211_BSS_CHAN_WIDTH_5:
945 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
946 break;
947 case NL80211_BSS_CHAN_WIDTH_10:
948 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
949 break;
950 default:
951 case NL80211_BSS_CHAN_WIDTH_20:
952 /* If scanning on oper channel, use whatever channel-type
953 * is currently in use.
954 */
955 oper_scan_width = cfg80211_chandef_to_scan_width(
956 &local->_oper_chandef);
957 if (chan == local->_oper_chandef.chan &&
958 oper_scan_width == scan_req->scan_width)
959 local->scan_chandef = local->_oper_chandef;
960 else
961 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
962 break;
963 case NL80211_BSS_CHAN_WIDTH_1:
964 case NL80211_BSS_CHAN_WIDTH_2:
965 /* shouldn't get here, S1G handled above */
966 WARN_ON(1);
967 break;
968 }
969
970set_channel:
971 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
972 skip = 1;
973
974 /* advance state machine to next channel/band */
975 local->scan_channel_idx++;
976
977 if (skip) {
978 /* if we skip this channel return to the decision state */
979 local->next_scan_state = SCAN_DECISION;
980 return;
981 }
982
983 /*
984 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
985 * (which unfortunately doesn't say _why_ step a) is done,
986 * but it waits for the probe delay or until a frame is
987 * received - and the received frame would update the NAV).
988 * For now, we do not support waiting until a frame is
989 * received.
990 *
991 * In any case, it is not necessary for a passive scan.
992 */
993 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
994 !scan_req->n_ssids) {
995 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
996 local->next_scan_state = SCAN_DECISION;
997 return;
998 }
999
1000 /* active scan, send probes */
1001 *next_delay = IEEE80211_PROBE_DELAY;
1002 local->next_scan_state = SCAN_SEND_PROBE;
1003}
1004
1005static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1006 unsigned long *next_delay)
1007{
1008 /* switch back to the operating channel */
1009 local->scan_chandef.chan = NULL;
1010 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
1011
1012 /* disable PS */
1013 ieee80211_offchannel_return(local);
1014
1015 *next_delay = HZ / 5;
1016 /* afterwards, resume scan & go to next channel */
1017 local->next_scan_state = SCAN_RESUME;
1018}
1019
1020static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1021 unsigned long *next_delay)
1022{
1023 ieee80211_offchannel_stop_vifs(local);
1024
1025 if (local->ops->flush) {
1026 ieee80211_flush_queues(local, NULL, false);
1027 *next_delay = 0;
1028 } else
1029 *next_delay = HZ / 10;
1030
1031 /* remember when we left the operating channel */
1032 local->leave_oper_channel_time = jiffies;
1033
1034 /* advance to the next channel to be scanned */
1035 local->next_scan_state = SCAN_SET_CHANNEL;
1036}
1037
1038void ieee80211_scan_work(struct work_struct *work)
1039{
1040 struct ieee80211_local *local =
1041 container_of(work, struct ieee80211_local, scan_work.work);
1042 struct ieee80211_sub_if_data *sdata;
1043 struct cfg80211_scan_request *scan_req;
1044 unsigned long next_delay = 0;
1045 bool aborted;
1046
1047 mutex_lock(&local->mtx);
1048
1049 if (!ieee80211_can_run_worker(local)) {
1050 aborted = true;
1051 goto out_complete;
1052 }
1053
1054 sdata = rcu_dereference_protected(local->scan_sdata,
1055 lockdep_is_held(&local->mtx));
1056 scan_req = rcu_dereference_protected(local->scan_req,
1057 lockdep_is_held(&local->mtx));
1058
1059 /* When scanning on-channel, the first-callback means completed. */
1060 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1061 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1062 goto out_complete;
1063 }
1064
1065 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1066 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1067 goto out_complete;
1068 }
1069
1070 if (!sdata || !scan_req)
1071 goto out;
1072
1073 if (!local->scanning) {
1074 int rc;
1075
1076 RCU_INIT_POINTER(local->scan_req, NULL);
1077 RCU_INIT_POINTER(local->scan_sdata, NULL);
1078
1079 rc = __ieee80211_start_scan(sdata, scan_req);
1080 if (rc) {
1081 /* need to complete scan in cfg80211 */
1082 rcu_assign_pointer(local->scan_req, scan_req);
1083 aborted = true;
1084 goto out_complete;
1085 } else
1086 goto out;
1087 }
1088
1089 /*
1090 * as long as no delay is required advance immediately
1091 * without scheduling a new work
1092 */
1093 do {
1094 if (!ieee80211_sdata_running(sdata)) {
1095 aborted = true;
1096 goto out_complete;
1097 }
1098
1099 switch (local->next_scan_state) {
1100 case SCAN_DECISION:
1101 /* if no more bands/channels left, complete scan */
1102 if (local->scan_channel_idx >= scan_req->n_channels) {
1103 aborted = false;
1104 goto out_complete;
1105 }
1106 ieee80211_scan_state_decision(local, &next_delay);
1107 break;
1108 case SCAN_SET_CHANNEL:
1109 ieee80211_scan_state_set_channel(local, &next_delay);
1110 break;
1111 case SCAN_SEND_PROBE:
1112 ieee80211_scan_state_send_probe(local, &next_delay);
1113 break;
1114 case SCAN_SUSPEND:
1115 ieee80211_scan_state_suspend(local, &next_delay);
1116 break;
1117 case SCAN_RESUME:
1118 ieee80211_scan_state_resume(local, &next_delay);
1119 break;
1120 case SCAN_ABORT:
1121 aborted = true;
1122 goto out_complete;
1123 }
1124 } while (next_delay == 0);
1125
1126 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
1127 goto out;
1128
1129out_complete:
1130 __ieee80211_scan_completed(&local->hw, aborted);
1131out:
1132 mutex_unlock(&local->mtx);
1133}
1134
1135int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1136 struct cfg80211_scan_request *req)
1137{
1138 int res;
1139
1140 mutex_lock(&sdata->local->mtx);
1141 res = __ieee80211_start_scan(sdata, req);
1142 mutex_unlock(&sdata->local->mtx);
1143
1144 return res;
1145}
1146
1147int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1148 const u8 *ssid, u8 ssid_len,
1149 struct ieee80211_channel **channels,
1150 unsigned int n_channels,
1151 enum nl80211_bss_scan_width scan_width)
1152{
1153 struct ieee80211_local *local = sdata->local;
1154 int ret = -EBUSY, i, n_ch = 0;
1155 enum nl80211_band band;
1156
1157 mutex_lock(&local->mtx);
1158
1159 /* busy scanning */
1160 if (local->scan_req)
1161 goto unlock;
1162
1163 /* fill internal scan request */
1164 if (!channels) {
1165 int max_n;
1166
1167 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1168 if (!local->hw.wiphy->bands[band] ||
1169 band == NL80211_BAND_6GHZ)
1170 continue;
1171
1172 max_n = local->hw.wiphy->bands[band]->n_channels;
1173 for (i = 0; i < max_n; i++) {
1174 struct ieee80211_channel *tmp_ch =
1175 &local->hw.wiphy->bands[band]->channels[i];
1176
1177 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1178 IEEE80211_CHAN_DISABLED))
1179 continue;
1180
1181 local->int_scan_req->channels[n_ch] = tmp_ch;
1182 n_ch++;
1183 }
1184 }
1185
1186 if (WARN_ON_ONCE(n_ch == 0))
1187 goto unlock;
1188
1189 local->int_scan_req->n_channels = n_ch;
1190 } else {
1191 for (i = 0; i < n_channels; i++) {
1192 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1193 IEEE80211_CHAN_DISABLED))
1194 continue;
1195
1196 local->int_scan_req->channels[n_ch] = channels[i];
1197 n_ch++;
1198 }
1199
1200 if (WARN_ON_ONCE(n_ch == 0))
1201 goto unlock;
1202
1203 local->int_scan_req->n_channels = n_ch;
1204 }
1205
1206 local->int_scan_req->ssids = &local->scan_ssid;
1207 local->int_scan_req->n_ssids = 1;
1208 local->int_scan_req->scan_width = scan_width;
1209 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1210 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1211
1212 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1213 unlock:
1214 mutex_unlock(&local->mtx);
1215 return ret;
1216}
1217
1218/*
1219 * Only call this function when a scan can't be queued -- under RTNL.
1220 */
1221void ieee80211_scan_cancel(struct ieee80211_local *local)
1222{
1223 /*
1224 * We are canceling software scan, or deferred scan that was not
1225 * yet really started (see __ieee80211_start_scan ).
1226 *
1227 * Regarding hardware scan:
1228 * - we can not call __ieee80211_scan_completed() as when
1229 * SCAN_HW_SCANNING bit is set this function change
1230 * local->hw_scan_req to operate on 5G band, what race with
1231 * driver which can use local->hw_scan_req
1232 *
1233 * - we can not cancel scan_work since driver can schedule it
1234 * by ieee80211_scan_completed(..., true) to finish scan
1235 *
1236 * Hence we only call the cancel_hw_scan() callback, but the low-level
1237 * driver is still responsible for calling ieee80211_scan_completed()
1238 * after the scan was completed/aborted.
1239 */
1240
1241 mutex_lock(&local->mtx);
1242 if (!local->scan_req)
1243 goto out;
1244
1245 /*
1246 * We have a scan running and the driver already reported completion,
1247 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1248 * cancelled.
1249 */
1250 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1251 test_bit(SCAN_COMPLETED, &local->scanning)) {
1252 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1253 goto out;
1254 }
1255
1256 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1257 /*
1258 * Make sure that __ieee80211_scan_completed doesn't trigger a
1259 * scan on another band.
1260 */
1261 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1262 if (local->ops->cancel_hw_scan)
1263 drv_cancel_hw_scan(local,
1264 rcu_dereference_protected(local->scan_sdata,
1265 lockdep_is_held(&local->mtx)));
1266 goto out;
1267 }
1268
1269 /*
1270 * If the work is currently running, it must be blocked on
1271 * the mutex, but we'll set scan_sdata = NULL and it'll
1272 * simply exit once it acquires the mutex.
1273 */
1274 cancel_delayed_work(&local->scan_work);
1275 /* and clean up */
1276 memset(&local->scan_info, 0, sizeof(local->scan_info));
1277 __ieee80211_scan_completed(&local->hw, true);
1278out:
1279 mutex_unlock(&local->mtx);
1280}
1281
1282int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1283 struct cfg80211_sched_scan_request *req)
1284{
1285 struct ieee80211_local *local = sdata->local;
1286 struct ieee80211_scan_ies sched_scan_ies = {};
1287 struct cfg80211_chan_def chandef;
1288 int ret, i, iebufsz, num_bands = 0;
1289 u32 rate_masks[NUM_NL80211_BANDS] = {};
1290 u8 bands_used = 0;
1291 u8 *ie;
1292 u32 flags = 0;
1293
1294 iebufsz = local->scan_ies_len + req->ie_len;
1295
1296 lockdep_assert_held(&local->mtx);
1297
1298 if (!local->ops->sched_scan_start)
1299 return -ENOTSUPP;
1300
1301 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1302 if (local->hw.wiphy->bands[i]) {
1303 bands_used |= BIT(i);
1304 rate_masks[i] = (u32) -1;
1305 num_bands++;
1306 }
1307 }
1308
1309 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1310 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1311
1312 ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1313 if (!ie) {
1314 ret = -ENOMEM;
1315 goto out;
1316 }
1317
1318 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1319
1320 ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1321 &sched_scan_ies, req->ie,
1322 req->ie_len, bands_used, rate_masks, &chandef,
1323 flags);
1324
1325 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1326 if (ret == 0) {
1327 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1328 rcu_assign_pointer(local->sched_scan_req, req);
1329 }
1330
1331 kfree(ie);
1332
1333out:
1334 if (ret) {
1335 /* Clean in case of failure after HW restart or upon resume. */
1336 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1337 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1338 }
1339
1340 return ret;
1341}
1342
1343int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1344 struct cfg80211_sched_scan_request *req)
1345{
1346 struct ieee80211_local *local = sdata->local;
1347 int ret;
1348
1349 mutex_lock(&local->mtx);
1350
1351 if (rcu_access_pointer(local->sched_scan_sdata)) {
1352 mutex_unlock(&local->mtx);
1353 return -EBUSY;
1354 }
1355
1356 ret = __ieee80211_request_sched_scan_start(sdata, req);
1357
1358 mutex_unlock(&local->mtx);
1359 return ret;
1360}
1361
1362int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1363{
1364 struct ieee80211_sub_if_data *sched_scan_sdata;
1365 int ret = -ENOENT;
1366
1367 mutex_lock(&local->mtx);
1368
1369 if (!local->ops->sched_scan_stop) {
1370 ret = -ENOTSUPP;
1371 goto out;
1372 }
1373
1374 /* We don't want to restart sched scan anymore. */
1375 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1376
1377 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1378 lockdep_is_held(&local->mtx));
1379 if (sched_scan_sdata) {
1380 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1381 if (!ret)
1382 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1383 }
1384out:
1385 mutex_unlock(&local->mtx);
1386
1387 return ret;
1388}
1389
1390void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1391{
1392 struct ieee80211_local *local = hw_to_local(hw);
1393
1394 trace_api_sched_scan_results(local);
1395
1396 cfg80211_sched_scan_results(hw->wiphy, 0);
1397}
1398EXPORT_SYMBOL(ieee80211_sched_scan_results);
1399
1400void ieee80211_sched_scan_end(struct ieee80211_local *local)
1401{
1402 mutex_lock(&local->mtx);
1403
1404 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1405 mutex_unlock(&local->mtx);
1406 return;
1407 }
1408
1409 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1410
1411 /* If sched scan was aborted by the driver. */
1412 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1413
1414 mutex_unlock(&local->mtx);
1415
1416 cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1417}
1418
1419void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1420{
1421 struct ieee80211_local *local =
1422 container_of(work, struct ieee80211_local,
1423 sched_scan_stopped_work);
1424
1425 ieee80211_sched_scan_end(local);
1426}
1427
1428void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1429{
1430 struct ieee80211_local *local = hw_to_local(hw);
1431
1432 trace_api_sched_scan_stopped(local);
1433
1434 /*
1435 * this shouldn't really happen, so for simplicity
1436 * simply ignore it, and let mac80211 reconfigure
1437 * the sched scan later on.
1438 */
1439 if (local->in_reconfig)
1440 return;
1441
1442 schedule_work(&local->sched_scan_stopped_work);
1443}
1444EXPORT_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);