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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) 2018-2024 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
58struct inform_bss_update_data {
59 struct ieee80211_rx_status *rx_status;
60 bool beacon;
61};
62
63void ieee80211_inform_bss(struct wiphy *wiphy,
64 struct cfg80211_bss *cbss,
65 const struct cfg80211_bss_ies *ies,
66 void *data)
67{
68 struct ieee80211_local *local = wiphy_priv(wiphy);
69 struct inform_bss_update_data *update_data = data;
70 struct ieee80211_bss *bss = (void *)cbss->priv;
71 struct ieee80211_rx_status *rx_status;
72 struct ieee802_11_elems *elems;
73 int clen, srlen;
74
75 /* This happens while joining an IBSS */
76 if (!update_data)
77 return;
78
79 elems = ieee802_11_parse_elems(ies->data, ies->len, false, NULL);
80 if (!elems)
81 return;
82
83 rx_status = update_data->rx_status;
84
85 if (update_data->beacon)
86 bss->device_ts_beacon = rx_status->device_timestamp;
87 else
88 bss->device_ts_presp = rx_status->device_timestamp;
89
90 if (elems->parse_error) {
91 if (update_data->beacon)
92 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
93 else
94 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
95 } else {
96 if (update_data->beacon)
97 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
98 else
99 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
100 }
101
102 /* save the ERP value so that it is available at association time */
103 if (elems->erp_info && (!elems->parse_error ||
104 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
105 bss->erp_value = elems->erp_info[0];
106 bss->has_erp_value = true;
107 if (!elems->parse_error)
108 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
109 }
110
111 /* replace old supported rates if we get new values */
112 if (!elems->parse_error ||
113 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
114 srlen = 0;
115 if (elems->supp_rates) {
116 clen = IEEE80211_MAX_SUPP_RATES;
117 if (clen > elems->supp_rates_len)
118 clen = elems->supp_rates_len;
119 memcpy(bss->supp_rates, elems->supp_rates, clen);
120 srlen += clen;
121 }
122 if (elems->ext_supp_rates) {
123 clen = IEEE80211_MAX_SUPP_RATES - srlen;
124 if (clen > elems->ext_supp_rates_len)
125 clen = elems->ext_supp_rates_len;
126 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
127 clen);
128 srlen += clen;
129 }
130 if (srlen) {
131 bss->supp_rates_len = srlen;
132 if (!elems->parse_error)
133 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
134 }
135 }
136
137 if (!elems->parse_error ||
138 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
139 bss->wmm_used = elems->wmm_param || elems->wmm_info;
140 bss->uapsd_supported = is_uapsd_supported(elems);
141 if (!elems->parse_error)
142 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
143 }
144
145 if (update_data->beacon) {
146 struct ieee80211_supported_band *sband =
147 local->hw.wiphy->bands[rx_status->band];
148 if (!(rx_status->encoding == RX_ENC_HT) &&
149 !(rx_status->encoding == RX_ENC_VHT))
150 bss->beacon_rate =
151 &sband->bitrates[rx_status->rate_idx];
152 }
153
154 if (elems->vht_cap_elem)
155 bss->vht_cap_info =
156 le32_to_cpu(elems->vht_cap_elem->vht_cap_info);
157 else
158 bss->vht_cap_info = 0;
159
160 kfree(elems);
161}
162
163struct ieee80211_bss *
164ieee80211_bss_info_update(struct ieee80211_local *local,
165 struct ieee80211_rx_status *rx_status,
166 struct ieee80211_mgmt *mgmt, size_t len,
167 struct ieee80211_channel *channel)
168{
169 bool beacon = ieee80211_is_beacon(mgmt->frame_control) ||
170 ieee80211_is_s1g_beacon(mgmt->frame_control);
171 struct cfg80211_bss *cbss;
172 struct inform_bss_update_data update_data = {
173 .rx_status = rx_status,
174 .beacon = beacon,
175 };
176 struct cfg80211_inform_bss bss_meta = {
177 .boottime_ns = rx_status->boottime_ns,
178 .drv_data = (void *)&update_data,
179 };
180 bool signal_valid;
181 struct ieee80211_sub_if_data *scan_sdata;
182
183 if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
184 bss_meta.signal = 0; /* invalid signal indication */
185 else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
186 bss_meta.signal = rx_status->signal * 100;
187 else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
188 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
189
190 bss_meta.chan = channel;
191
192 rcu_read_lock();
193 scan_sdata = rcu_dereference(local->scan_sdata);
194 if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
195 scan_sdata->vif.cfg.assoc &&
196 ieee80211_have_rx_timestamp(rx_status)) {
197 struct ieee80211_bss_conf *link_conf = NULL;
198
199 /* for an MLO connection, set the TSF data only in case we have
200 * an indication on which of the links the frame was received
201 */
202 if (ieee80211_vif_is_mld(&scan_sdata->vif)) {
203 if (rx_status->link_valid) {
204 s8 link_id = rx_status->link_id;
205
206 link_conf =
207 rcu_dereference(scan_sdata->vif.link_conf[link_id]);
208 }
209 } else {
210 link_conf = &scan_sdata->vif.bss_conf;
211 }
212
213 if (link_conf) {
214 bss_meta.parent_tsf =
215 ieee80211_calculate_rx_timestamp(local,
216 rx_status,
217 len + FCS_LEN,
218 24);
219
220 ether_addr_copy(bss_meta.parent_bssid,
221 link_conf->bssid);
222 }
223 }
224 rcu_read_unlock();
225
226 cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
227 mgmt, len, GFP_ATOMIC);
228 if (!cbss)
229 return NULL;
230
231 /* In case the signal is invalid update the status */
232 signal_valid = channel == cbss->channel;
233 if (!signal_valid)
234 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
235
236 return (void *)cbss->priv;
237}
238
239static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
240 struct ieee80211_channel *channel,
241 u32 scan_flags, const u8 *da)
242{
243 if (!sdata)
244 return false;
245
246 /* accept broadcast on 6 GHz and for OCE */
247 if (is_broadcast_ether_addr(da) &&
248 (channel->band == NL80211_BAND_6GHZ ||
249 scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP))
250 return true;
251
252 if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
253 return true;
254 return ether_addr_equal(da, sdata->vif.addr);
255}
256
257void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
258{
259 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
260 struct ieee80211_mgmt *mgmt = (void *)skb->data;
261 struct ieee80211_bss *bss;
262 struct ieee80211_channel *channel;
263 size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
264 u.probe_resp.variable);
265
266 if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
267 !ieee80211_is_beacon(mgmt->frame_control) &&
268 !ieee80211_is_s1g_beacon(mgmt->frame_control))
269 return;
270
271 if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
272 if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
273 min_hdr_len = offsetof(struct ieee80211_ext,
274 u.s1g_short_beacon.variable);
275 else
276 min_hdr_len = offsetof(struct ieee80211_ext,
277 u.s1g_beacon);
278 }
279
280 if (skb->len < min_hdr_len)
281 return;
282
283 if (test_and_clear_bit(SCAN_BEACON_WAIT, &local->scanning)) {
284 /*
285 * we were passive scanning because of radar/no-IR, but
286 * the beacon/proberesp rx gives us an opportunity to upgrade
287 * to active scan
288 */
289 set_bit(SCAN_BEACON_DONE, &local->scanning);
290 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
291 }
292
293 channel = ieee80211_get_channel_khz(local->hw.wiphy,
294 ieee80211_rx_status_to_khz(rx_status));
295
296 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
297 return;
298
299 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
300 struct ieee80211_sub_if_data *sdata1, *sdata2;
301 struct cfg80211_scan_request *scan_req;
302 struct cfg80211_sched_scan_request *sched_scan_req;
303 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
304
305 sdata1 = rcu_dereference(local->scan_sdata);
306 sdata2 = rcu_dereference(local->sched_scan_sdata);
307
308 if (likely(!sdata1 && !sdata2))
309 return;
310
311 scan_req = rcu_dereference(local->scan_req);
312 sched_scan_req = rcu_dereference(local->sched_scan_req);
313
314 if (scan_req)
315 scan_req_flags = scan_req->flags;
316
317 if (sched_scan_req)
318 sched_scan_req_flags = sched_scan_req->flags;
319
320 /* ignore ProbeResp to foreign address or non-bcast (OCE)
321 * unless scanning with randomised address
322 */
323 if (!ieee80211_scan_accept_presp(sdata1, channel,
324 scan_req_flags,
325 mgmt->da) &&
326 !ieee80211_scan_accept_presp(sdata2, channel,
327 sched_scan_req_flags,
328 mgmt->da))
329 return;
330 } else {
331 /* Beacons are expected only with broadcast address */
332 if (!is_broadcast_ether_addr(mgmt->da))
333 return;
334 }
335
336 /* Do not update the BSS table in case of only monitor interfaces */
337 if (local->open_count == local->monitors)
338 return;
339
340 bss = ieee80211_bss_info_update(local, rx_status,
341 mgmt, skb->len,
342 channel);
343 if (bss)
344 ieee80211_rx_bss_put(local, bss);
345}
346
347static void ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef)
348{
349 memset(chandef, 0, sizeof(*chandef));
350
351 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
352}
353
354/* return false if no more work */
355static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
356{
357 struct ieee80211_local *local = sdata->local;
358 struct cfg80211_scan_request *req;
359 struct cfg80211_chan_def chandef;
360 u8 bands_used = 0;
361 int i, ielen;
362 u32 *n_chans;
363 u32 flags = 0;
364
365 req = rcu_dereference_protected(local->scan_req,
366 lockdep_is_held(&local->hw.wiphy->mtx));
367
368 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
369 return false;
370
371 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
372 local->hw_scan_req->req.n_channels = req->n_channels;
373
374 for (i = 0; i < req->n_channels; i++) {
375 local->hw_scan_req->req.channels[i] = req->channels[i];
376 bands_used |= BIT(req->channels[i]->band);
377 }
378 } else {
379 do {
380 if (local->hw_scan_band == NUM_NL80211_BANDS)
381 return false;
382
383 n_chans = &local->hw_scan_req->req.n_channels;
384 *n_chans = 0;
385
386 for (i = 0; i < req->n_channels; i++) {
387 if (req->channels[i]->band !=
388 local->hw_scan_band)
389 continue;
390 local->hw_scan_req->req.channels[(*n_chans)++] =
391 req->channels[i];
392
393 bands_used |= BIT(req->channels[i]->band);
394 }
395
396 local->hw_scan_band++;
397 } while (!*n_chans);
398 }
399
400 ieee80211_prepare_scan_chandef(&chandef);
401
402 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
403 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
404
405 ielen = ieee80211_build_preq_ies(sdata,
406 (u8 *)local->hw_scan_req->req.ie,
407 local->hw_scan_ies_bufsize,
408 &local->hw_scan_req->ies,
409 req->ie, req->ie_len,
410 bands_used, req->rates, &chandef,
411 flags);
412 if (ielen < 0)
413 return false;
414 local->hw_scan_req->req.ie_len = ielen;
415 local->hw_scan_req->req.no_cck = req->no_cck;
416 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
417 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
418 req->mac_addr_mask);
419 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
420
421 return true;
422}
423
424static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
425{
426 struct ieee80211_local *local = hw_to_local(hw);
427 bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
428 bool was_scanning = local->scanning;
429 struct cfg80211_scan_request *scan_req;
430 struct ieee80211_sub_if_data *scan_sdata;
431 struct ieee80211_sub_if_data *sdata;
432
433 lockdep_assert_wiphy(local->hw.wiphy);
434
435 /*
436 * It's ok to abort a not-yet-running scan (that
437 * we have one at all will be verified by checking
438 * local->scan_req next), but not to complete it
439 * successfully.
440 */
441 if (WARN_ON(!local->scanning && !aborted))
442 aborted = true;
443
444 if (WARN_ON(!local->scan_req))
445 return;
446
447 scan_sdata = rcu_dereference_protected(local->scan_sdata,
448 lockdep_is_held(&local->hw.wiphy->mtx));
449
450 if (hw_scan && !aborted &&
451 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
452 ieee80211_prep_hw_scan(scan_sdata)) {
453 int rc;
454
455 rc = drv_hw_scan(local,
456 rcu_dereference_protected(local->scan_sdata,
457 lockdep_is_held(&local->hw.wiphy->mtx)),
458 local->hw_scan_req);
459
460 if (rc == 0)
461 return;
462
463 /* HW scan failed and is going to be reported as aborted,
464 * so clear old scan info.
465 */
466 memset(&local->scan_info, 0, sizeof(local->scan_info));
467 aborted = true;
468 }
469
470 kfree(local->hw_scan_req);
471 local->hw_scan_req = NULL;
472
473 scan_req = rcu_dereference_protected(local->scan_req,
474 lockdep_is_held(&local->hw.wiphy->mtx));
475
476 RCU_INIT_POINTER(local->scan_req, NULL);
477 RCU_INIT_POINTER(local->scan_sdata, NULL);
478
479 local->scanning = 0;
480 local->scan_chandef.chan = NULL;
481
482 synchronize_rcu();
483
484 if (scan_req != local->int_scan_req) {
485 local->scan_info.aborted = aborted;
486 cfg80211_scan_done(scan_req, &local->scan_info);
487 }
488
489 /* Set power back to normal operating levels. */
490 ieee80211_hw_conf_chan(local);
491
492 if (!hw_scan && was_scanning) {
493 ieee80211_configure_filter(local);
494 drv_sw_scan_complete(local, scan_sdata);
495 ieee80211_offchannel_return(local);
496 }
497
498 ieee80211_recalc_idle(local);
499
500 ieee80211_mlme_notify_scan_completed(local);
501 ieee80211_ibss_notify_scan_completed(local);
502
503 /* Requeue all the work that might have been ignored while
504 * the scan was in progress; if there was none this will
505 * just be a no-op for the particular interface.
506 */
507 list_for_each_entry(sdata, &local->interfaces, list) {
508 if (ieee80211_sdata_running(sdata))
509 wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
510 }
511
512 if (was_scanning)
513 ieee80211_start_next_roc(local);
514}
515
516void ieee80211_scan_completed(struct ieee80211_hw *hw,
517 struct cfg80211_scan_info *info)
518{
519 struct ieee80211_local *local = hw_to_local(hw);
520
521 trace_api_scan_completed(local, info->aborted);
522
523 set_bit(SCAN_COMPLETED, &local->scanning);
524 if (info->aborted)
525 set_bit(SCAN_ABORTED, &local->scanning);
526
527 memcpy(&local->scan_info, info, sizeof(*info));
528
529 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
530}
531EXPORT_SYMBOL(ieee80211_scan_completed);
532
533static int ieee80211_start_sw_scan(struct ieee80211_local *local,
534 struct ieee80211_sub_if_data *sdata)
535{
536 /* Software scan is not supported in multi-channel cases */
537 if (!local->emulate_chanctx)
538 return -EOPNOTSUPP;
539
540 /*
541 * Hardware/driver doesn't support hw_scan, so use software
542 * scanning instead. First send a nullfunc frame with power save
543 * bit on so that AP will buffer the frames for us while we are not
544 * listening, then send probe requests to each channel and wait for
545 * the responses. After all channels are scanned, tune back to the
546 * original channel and send a nullfunc frame with power save bit
547 * off to trigger the AP to send us all the buffered frames.
548 *
549 * Note that while local->sw_scanning is true everything else but
550 * nullfunc frames and probe requests will be dropped in
551 * ieee80211_tx_h_check_assoc().
552 */
553 drv_sw_scan_start(local, sdata, local->scan_addr);
554
555 local->leave_oper_channel_time = jiffies;
556 local->next_scan_state = SCAN_DECISION;
557 local->scan_channel_idx = 0;
558
559 ieee80211_offchannel_stop_vifs(local);
560
561 /* ensure nullfunc is transmitted before leaving operating channel */
562 ieee80211_flush_queues(local, NULL, false);
563
564 ieee80211_configure_filter(local);
565
566 /* We need to set power level at maximum rate for scanning. */
567 ieee80211_hw_conf_chan(local);
568
569 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work, 0);
570
571 return 0;
572}
573
574static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
575{
576 struct ieee80211_local *local = sdata->local;
577 struct ieee80211_sub_if_data *sdata_iter;
578 unsigned int link_id;
579
580 lockdep_assert_wiphy(local->hw.wiphy);
581
582 if (!ieee80211_is_radar_required(local))
583 return true;
584
585 if (!regulatory_pre_cac_allowed(local->hw.wiphy))
586 return false;
587
588 list_for_each_entry(sdata_iter, &local->interfaces, list) {
589 for_each_valid_link(&sdata_iter->wdev, link_id)
590 if (sdata_iter->wdev.links[link_id].cac_started)
591 return false;
592 }
593
594 return true;
595}
596
597static bool ieee80211_can_scan(struct ieee80211_local *local,
598 struct ieee80211_sub_if_data *sdata)
599{
600 if (!__ieee80211_can_leave_ch(sdata))
601 return false;
602
603 if (!list_empty(&local->roc_list))
604 return false;
605
606 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
607 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
608 return false;
609
610 return true;
611}
612
613void ieee80211_run_deferred_scan(struct ieee80211_local *local)
614{
615 lockdep_assert_wiphy(local->hw.wiphy);
616
617 if (!local->scan_req || local->scanning)
618 return;
619
620 if (!ieee80211_can_scan(local,
621 rcu_dereference_protected(
622 local->scan_sdata,
623 lockdep_is_held(&local->hw.wiphy->mtx))))
624 return;
625
626 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
627 round_jiffies_relative(0));
628}
629
630static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
631 const u8 *src, const u8 *dst,
632 const u8 *ssid, size_t ssid_len,
633 const u8 *ie, size_t ie_len,
634 u32 ratemask, u32 flags, u32 tx_flags,
635 struct ieee80211_channel *channel)
636{
637 struct sk_buff *skb;
638
639 skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
640 ssid, ssid_len,
641 ie, ie_len, flags);
642
643 if (skb) {
644 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
645 struct ieee80211_hdr *hdr = (void *)skb->data;
646 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
647 u16 sn = get_random_u16();
648
649 info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
650 hdr->seq_ctrl =
651 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
652 }
653 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
654 IEEE80211_SKB_CB(skb)->control.flags |= IEEE80211_TX_CTRL_DONT_USE_RATE_MASK;
655 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
656 }
657}
658
659static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
660 unsigned long *next_delay)
661{
662 int i;
663 struct ieee80211_sub_if_data *sdata;
664 struct cfg80211_scan_request *scan_req;
665 enum nl80211_band band = local->hw.conf.chandef.chan->band;
666 u32 flags = 0, tx_flags;
667
668 scan_req = rcu_dereference_protected(local->scan_req,
669 lockdep_is_held(&local->hw.wiphy->mtx));
670
671 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
672 if (scan_req->no_cck)
673 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
674 if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
675 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
676 if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
677 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
678
679 sdata = rcu_dereference_protected(local->scan_sdata,
680 lockdep_is_held(&local->hw.wiphy->mtx));
681
682 for (i = 0; i < scan_req->n_ssids; i++)
683 ieee80211_send_scan_probe_req(
684 sdata, local->scan_addr, scan_req->bssid,
685 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
686 scan_req->ie, scan_req->ie_len,
687 scan_req->rates[band], flags,
688 tx_flags, local->hw.conf.chandef.chan);
689
690 /*
691 * After sending probe requests, wait for probe responses
692 * on the channel.
693 */
694 *next_delay = msecs_to_jiffies(scan_req->duration) >
695 IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME ?
696 msecs_to_jiffies(scan_req->duration) - IEEE80211_PROBE_DELAY :
697 IEEE80211_CHANNEL_TIME;
698 local->next_scan_state = SCAN_DECISION;
699}
700
701static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
702 struct cfg80211_scan_request *req)
703{
704 struct ieee80211_local *local = sdata->local;
705 bool hw_scan = local->ops->hw_scan;
706 int rc;
707
708 lockdep_assert_wiphy(local->hw.wiphy);
709
710 if (local->scan_req)
711 return -EBUSY;
712
713 /* For an MLO connection, if a link ID was specified, validate that it
714 * is indeed active.
715 */
716 if (ieee80211_vif_is_mld(&sdata->vif) && req->tsf_report_link_id >= 0 &&
717 !(sdata->vif.active_links & BIT(req->tsf_report_link_id)))
718 return -EINVAL;
719
720 if (!__ieee80211_can_leave_ch(sdata))
721 return -EBUSY;
722
723 if (!ieee80211_can_scan(local, sdata)) {
724 /* wait for the work to finish/time out */
725 rcu_assign_pointer(local->scan_req, req);
726 rcu_assign_pointer(local->scan_sdata, sdata);
727 return 0;
728 }
729
730 again:
731 if (hw_scan) {
732 u8 *ies;
733
734 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
735
736 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
737 int i, n_bands = 0;
738 u8 bands_counted = 0;
739
740 for (i = 0; i < req->n_channels; i++) {
741 if (bands_counted & BIT(req->channels[i]->band))
742 continue;
743 bands_counted |= BIT(req->channels[i]->band);
744 n_bands++;
745 }
746
747 local->hw_scan_ies_bufsize *= n_bands;
748 }
749
750 local->hw_scan_req = kmalloc(struct_size(local->hw_scan_req,
751 req.channels,
752 req->n_channels) +
753 local->hw_scan_ies_bufsize,
754 GFP_KERNEL);
755 if (!local->hw_scan_req)
756 return -ENOMEM;
757
758 local->hw_scan_req->req.ssids = req->ssids;
759 local->hw_scan_req->req.n_ssids = req->n_ssids;
760 /* None of the channels are actually set
761 * up but let UBSAN know the boundaries.
762 */
763 local->hw_scan_req->req.n_channels = req->n_channels;
764
765 ies = (u8 *)local->hw_scan_req +
766 sizeof(*local->hw_scan_req) +
767 req->n_channels * sizeof(req->channels[0]);
768 local->hw_scan_req->req.ie = ies;
769 local->hw_scan_req->req.flags = req->flags;
770 eth_broadcast_addr(local->hw_scan_req->req.bssid);
771 local->hw_scan_req->req.duration = req->duration;
772 local->hw_scan_req->req.duration_mandatory =
773 req->duration_mandatory;
774 local->hw_scan_req->req.tsf_report_link_id =
775 req->tsf_report_link_id;
776
777 local->hw_scan_band = 0;
778 local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
779 local->hw_scan_req->req.scan_6ghz_params =
780 req->scan_6ghz_params;
781 local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
782
783 /*
784 * After allocating local->hw_scan_req, we must
785 * go through until ieee80211_prep_hw_scan(), so
786 * anything that might be changed here and leave
787 * this function early must not go after this
788 * allocation.
789 */
790 }
791
792 rcu_assign_pointer(local->scan_req, req);
793 rcu_assign_pointer(local->scan_sdata, sdata);
794
795 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
796 get_random_mask_addr(local->scan_addr,
797 req->mac_addr,
798 req->mac_addr_mask);
799 else
800 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
801
802 if (hw_scan) {
803 __set_bit(SCAN_HW_SCANNING, &local->scanning);
804 } else if ((req->n_channels == 1) &&
805 (req->channels[0] == local->hw.conf.chandef.chan)) {
806 /*
807 * If we are scanning only on the operating channel
808 * then we do not need to stop normal activities
809 */
810 unsigned long next_delay;
811
812 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
813
814 ieee80211_recalc_idle(local);
815
816 /* Notify driver scan is starting, keep order of operations
817 * same as normal software scan, in case that matters. */
818 drv_sw_scan_start(local, sdata, local->scan_addr);
819
820 ieee80211_configure_filter(local); /* accept probe-responses */
821
822 /* We need to ensure power level is at max for scanning. */
823 ieee80211_hw_conf_chan(local);
824
825 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
826 IEEE80211_CHAN_RADAR)) ||
827 !req->n_ssids) {
828 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
829 if (req->n_ssids)
830 set_bit(SCAN_BEACON_WAIT, &local->scanning);
831 } else {
832 ieee80211_scan_state_send_probe(local, &next_delay);
833 next_delay = IEEE80211_CHANNEL_TIME;
834 }
835
836 /* Now, just wait a bit and we are all done! */
837 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
838 next_delay);
839 return 0;
840 } else {
841 /* Do normal software scan */
842 __set_bit(SCAN_SW_SCANNING, &local->scanning);
843 }
844
845 ieee80211_recalc_idle(local);
846
847 if (hw_scan) {
848 WARN_ON(!ieee80211_prep_hw_scan(sdata));
849 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
850 } else {
851 rc = ieee80211_start_sw_scan(local, sdata);
852 }
853
854 if (rc) {
855 kfree(local->hw_scan_req);
856 local->hw_scan_req = NULL;
857 local->scanning = 0;
858
859 ieee80211_recalc_idle(local);
860
861 local->scan_req = NULL;
862 RCU_INIT_POINTER(local->scan_sdata, NULL);
863 }
864
865 if (hw_scan && rc == 1) {
866 /*
867 * we can't fall back to software for P2P-GO
868 * as it must update NoA etc.
869 */
870 if (ieee80211_vif_type_p2p(&sdata->vif) ==
871 NL80211_IFTYPE_P2P_GO)
872 return -EOPNOTSUPP;
873 hw_scan = false;
874 goto again;
875 }
876
877 return rc;
878}
879
880static unsigned long
881ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
882{
883 /*
884 * TODO: channel switching also consumes quite some time,
885 * add that delay as well to get a better estimation
886 */
887 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
888 return IEEE80211_PASSIVE_CHANNEL_TIME;
889 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
890}
891
892static void ieee80211_scan_state_decision(struct ieee80211_local *local,
893 unsigned long *next_delay)
894{
895 bool associated = false;
896 bool tx_empty = true;
897 bool bad_latency;
898 struct ieee80211_sub_if_data *sdata;
899 struct ieee80211_channel *next_chan;
900 enum mac80211_scan_state next_scan_state;
901 struct cfg80211_scan_request *scan_req;
902
903 lockdep_assert_wiphy(local->hw.wiphy);
904
905 /*
906 * check if at least one STA interface is associated,
907 * check if at least one STA interface has pending tx frames
908 * and grab the lowest used beacon interval
909 */
910 list_for_each_entry(sdata, &local->interfaces, list) {
911 if (!ieee80211_sdata_running(sdata))
912 continue;
913
914 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
915 if (sdata->u.mgd.associated) {
916 associated = true;
917
918 if (!qdisc_all_tx_empty(sdata->dev)) {
919 tx_empty = false;
920 break;
921 }
922 }
923 }
924 }
925
926 scan_req = rcu_dereference_protected(local->scan_req,
927 lockdep_is_held(&local->hw.wiphy->mtx));
928
929 next_chan = scan_req->channels[local->scan_channel_idx];
930
931 /*
932 * we're currently scanning a different channel, let's
933 * see if we can scan another channel without interfering
934 * with the current traffic situation.
935 *
936 * Keep good latency, do not stay off-channel more than 125 ms.
937 */
938
939 bad_latency = time_after(jiffies +
940 ieee80211_scan_get_channel_time(next_chan),
941 local->leave_oper_channel_time + HZ / 8);
942
943 if (associated && !tx_empty) {
944 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
945 next_scan_state = SCAN_ABORT;
946 else
947 next_scan_state = SCAN_SUSPEND;
948 } else if (associated && bad_latency) {
949 next_scan_state = SCAN_SUSPEND;
950 } else {
951 next_scan_state = SCAN_SET_CHANNEL;
952 }
953
954 local->next_scan_state = next_scan_state;
955
956 *next_delay = 0;
957}
958
959static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
960 unsigned long *next_delay)
961{
962 int skip;
963 struct ieee80211_channel *chan;
964 struct cfg80211_scan_request *scan_req;
965
966 scan_req = rcu_dereference_protected(local->scan_req,
967 lockdep_is_held(&local->hw.wiphy->mtx));
968
969 skip = 0;
970 chan = scan_req->channels[local->scan_channel_idx];
971
972 local->scan_chandef.chan = chan;
973 local->scan_chandef.center_freq1 = chan->center_freq;
974 local->scan_chandef.freq1_offset = chan->freq_offset;
975 local->scan_chandef.center_freq2 = 0;
976
977 /* For scanning on the S1G band, detect the channel width according to
978 * the channel being scanned.
979 */
980 if (chan->band == NL80211_BAND_S1GHZ) {
981 local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
982 goto set_channel;
983 }
984
985 /* If scanning on oper channel, use whatever channel-type
986 * is currently in use.
987 */
988 if (chan == local->hw.conf.chandef.chan)
989 local->scan_chandef = local->hw.conf.chandef;
990 else
991 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
992
993set_channel:
994 if (ieee80211_hw_conf_chan(local))
995 skip = 1;
996
997 /* advance state machine to next channel/band */
998 local->scan_channel_idx++;
999
1000 if (skip) {
1001 /* if we skip this channel return to the decision state */
1002 local->next_scan_state = SCAN_DECISION;
1003 return;
1004 }
1005
1006 /*
1007 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
1008 * (which unfortunately doesn't say _why_ step a) is done,
1009 * but it waits for the probe delay or until a frame is
1010 * received - and the received frame would update the NAV).
1011 * For now, we do not support waiting until a frame is
1012 * received.
1013 *
1014 * In any case, it is not necessary for a passive scan.
1015 */
1016 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
1017 !scan_req->n_ssids) {
1018 *next_delay = max(msecs_to_jiffies(scan_req->duration),
1019 IEEE80211_PASSIVE_CHANNEL_TIME);
1020 local->next_scan_state = SCAN_DECISION;
1021 if (scan_req->n_ssids)
1022 set_bit(SCAN_BEACON_WAIT, &local->scanning);
1023 return;
1024 }
1025
1026 /* active scan, send probes */
1027 *next_delay = IEEE80211_PROBE_DELAY;
1028 local->next_scan_state = SCAN_SEND_PROBE;
1029}
1030
1031static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1032 unsigned long *next_delay)
1033{
1034 /* switch back to the operating channel */
1035 local->scan_chandef.chan = NULL;
1036 ieee80211_hw_conf_chan(local);
1037
1038 /* disable PS */
1039 ieee80211_offchannel_return(local);
1040
1041 *next_delay = HZ / 5;
1042 /* afterwards, resume scan & go to next channel */
1043 local->next_scan_state = SCAN_RESUME;
1044}
1045
1046static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1047 unsigned long *next_delay)
1048{
1049 ieee80211_offchannel_stop_vifs(local);
1050
1051 if (local->ops->flush) {
1052 ieee80211_flush_queues(local, NULL, false);
1053 *next_delay = 0;
1054 } else
1055 *next_delay = HZ / 10;
1056
1057 /* remember when we left the operating channel */
1058 local->leave_oper_channel_time = jiffies;
1059
1060 /* advance to the next channel to be scanned */
1061 local->next_scan_state = SCAN_SET_CHANNEL;
1062}
1063
1064void ieee80211_scan_work(struct wiphy *wiphy, struct wiphy_work *work)
1065{
1066 struct ieee80211_local *local =
1067 container_of(work, struct ieee80211_local, scan_work.work);
1068 struct ieee80211_sub_if_data *sdata;
1069 struct cfg80211_scan_request *scan_req;
1070 unsigned long next_delay = 0;
1071 bool aborted;
1072
1073 lockdep_assert_wiphy(local->hw.wiphy);
1074
1075 if (!ieee80211_can_run_worker(local)) {
1076 aborted = true;
1077 goto out_complete;
1078 }
1079
1080 sdata = rcu_dereference_protected(local->scan_sdata,
1081 lockdep_is_held(&local->hw.wiphy->mtx));
1082 scan_req = rcu_dereference_protected(local->scan_req,
1083 lockdep_is_held(&local->hw.wiphy->mtx));
1084
1085 /* When scanning on-channel, the first-callback means completed. */
1086 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1087 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1088 goto out_complete;
1089 }
1090
1091 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1092 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1093 goto out_complete;
1094 }
1095
1096 if (!sdata || !scan_req)
1097 return;
1098
1099 if (!local->scanning) {
1100 int rc;
1101
1102 RCU_INIT_POINTER(local->scan_req, NULL);
1103 RCU_INIT_POINTER(local->scan_sdata, NULL);
1104
1105 rc = __ieee80211_start_scan(sdata, scan_req);
1106 if (!rc)
1107 return;
1108 /* need to complete scan in cfg80211 */
1109 rcu_assign_pointer(local->scan_req, scan_req);
1110 aborted = true;
1111 goto out_complete;
1112 }
1113
1114 clear_bit(SCAN_BEACON_WAIT, &local->scanning);
1115
1116 /*
1117 * as long as no delay is required advance immediately
1118 * without scheduling a new work
1119 */
1120 do {
1121 if (!ieee80211_sdata_running(sdata)) {
1122 aborted = true;
1123 goto out_complete;
1124 }
1125
1126 if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) &&
1127 local->next_scan_state == SCAN_DECISION)
1128 local->next_scan_state = SCAN_SEND_PROBE;
1129
1130 switch (local->next_scan_state) {
1131 case SCAN_DECISION:
1132 /* if no more bands/channels left, complete scan */
1133 if (local->scan_channel_idx >= scan_req->n_channels) {
1134 aborted = false;
1135 goto out_complete;
1136 }
1137 ieee80211_scan_state_decision(local, &next_delay);
1138 break;
1139 case SCAN_SET_CHANNEL:
1140 ieee80211_scan_state_set_channel(local, &next_delay);
1141 break;
1142 case SCAN_SEND_PROBE:
1143 ieee80211_scan_state_send_probe(local, &next_delay);
1144 break;
1145 case SCAN_SUSPEND:
1146 ieee80211_scan_state_suspend(local, &next_delay);
1147 break;
1148 case SCAN_RESUME:
1149 ieee80211_scan_state_resume(local, &next_delay);
1150 break;
1151 case SCAN_ABORT:
1152 aborted = true;
1153 goto out_complete;
1154 }
1155 } while (next_delay == 0);
1156
1157 wiphy_delayed_work_queue(local->hw.wiphy, &local->scan_work,
1158 next_delay);
1159 return;
1160
1161out_complete:
1162 __ieee80211_scan_completed(&local->hw, aborted);
1163}
1164
1165int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1166 struct cfg80211_scan_request *req)
1167{
1168 lockdep_assert_wiphy(sdata->local->hw.wiphy);
1169
1170 return __ieee80211_start_scan(sdata, req);
1171}
1172
1173int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1174 const u8 *ssid, u8 ssid_len,
1175 struct ieee80211_channel **channels,
1176 unsigned int n_channels)
1177{
1178 struct ieee80211_local *local = sdata->local;
1179 int i, n_ch = 0;
1180 enum nl80211_band band;
1181
1182 lockdep_assert_wiphy(local->hw.wiphy);
1183
1184 /* busy scanning */
1185 if (local->scan_req)
1186 return -EBUSY;
1187
1188 /* fill internal scan request */
1189 if (!channels) {
1190 int max_n;
1191
1192 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1193 if (!local->hw.wiphy->bands[band] ||
1194 band == NL80211_BAND_6GHZ)
1195 continue;
1196
1197 max_n = local->hw.wiphy->bands[band]->n_channels;
1198 for (i = 0; i < max_n; i++) {
1199 struct ieee80211_channel *tmp_ch =
1200 &local->hw.wiphy->bands[band]->channels[i];
1201
1202 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1203 IEEE80211_CHAN_DISABLED) ||
1204 !cfg80211_wdev_channel_allowed(&sdata->wdev,
1205 tmp_ch))
1206 continue;
1207
1208 local->int_scan_req->channels[n_ch] = tmp_ch;
1209 n_ch++;
1210 }
1211 }
1212
1213 if (WARN_ON_ONCE(n_ch == 0))
1214 return -EINVAL;
1215
1216 local->int_scan_req->n_channels = n_ch;
1217 } else {
1218 for (i = 0; i < n_channels; i++) {
1219 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1220 IEEE80211_CHAN_DISABLED) ||
1221 !cfg80211_wdev_channel_allowed(&sdata->wdev,
1222 channels[i]))
1223 continue;
1224
1225 local->int_scan_req->channels[n_ch] = channels[i];
1226 n_ch++;
1227 }
1228
1229 if (n_ch == 0)
1230 return -EINVAL;
1231
1232 local->int_scan_req->n_channels = n_ch;
1233 }
1234
1235 local->int_scan_req->ssids = &local->scan_ssid;
1236 local->int_scan_req->n_ssids = 1;
1237 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1238 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1239
1240 return __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1241}
1242
1243void ieee80211_scan_cancel(struct ieee80211_local *local)
1244{
1245 /* ensure a new scan cannot be queued */
1246 lockdep_assert_wiphy(local->hw.wiphy);
1247
1248 /*
1249 * We are canceling software scan, or deferred scan that was not
1250 * yet really started (see __ieee80211_start_scan ).
1251 *
1252 * Regarding hardware scan:
1253 * - we can not call __ieee80211_scan_completed() as when
1254 * SCAN_HW_SCANNING bit is set this function change
1255 * local->hw_scan_req to operate on 5G band, what race with
1256 * driver which can use local->hw_scan_req
1257 *
1258 * - we can not cancel scan_work since driver can schedule it
1259 * by ieee80211_scan_completed(..., true) to finish scan
1260 *
1261 * Hence we only call the cancel_hw_scan() callback, but the low-level
1262 * driver is still responsible for calling ieee80211_scan_completed()
1263 * after the scan was completed/aborted.
1264 */
1265
1266 if (!local->scan_req)
1267 return;
1268
1269 /*
1270 * We have a scan running and the driver already reported completion,
1271 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1272 * cancelled.
1273 */
1274 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1275 test_bit(SCAN_COMPLETED, &local->scanning)) {
1276 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1277 return;
1278 }
1279
1280 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1281 /*
1282 * Make sure that __ieee80211_scan_completed doesn't trigger a
1283 * scan on another band.
1284 */
1285 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1286 if (local->ops->cancel_hw_scan)
1287 drv_cancel_hw_scan(local,
1288 rcu_dereference_protected(local->scan_sdata,
1289 lockdep_is_held(&local->hw.wiphy->mtx)));
1290 return;
1291 }
1292
1293 wiphy_delayed_work_cancel(local->hw.wiphy, &local->scan_work);
1294 /* and clean up */
1295 memset(&local->scan_info, 0, sizeof(local->scan_info));
1296 __ieee80211_scan_completed(&local->hw, true);
1297}
1298
1299int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1300 struct cfg80211_sched_scan_request *req)
1301{
1302 struct ieee80211_local *local = sdata->local;
1303 struct ieee80211_scan_ies sched_scan_ies = {};
1304 struct cfg80211_chan_def chandef;
1305 int ret, i, iebufsz, num_bands = 0;
1306 u32 rate_masks[NUM_NL80211_BANDS] = {};
1307 u8 bands_used = 0;
1308 u8 *ie;
1309 u32 flags = 0;
1310
1311 lockdep_assert_wiphy(local->hw.wiphy);
1312
1313 iebufsz = local->scan_ies_len + req->ie_len;
1314
1315 if (!local->ops->sched_scan_start)
1316 return -EOPNOTSUPP;
1317
1318 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1319 if (local->hw.wiphy->bands[i]) {
1320 bands_used |= BIT(i);
1321 rate_masks[i] = (u32) -1;
1322 num_bands++;
1323 }
1324 }
1325
1326 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1327 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1328
1329 ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1330 if (!ie) {
1331 ret = -ENOMEM;
1332 goto out;
1333 }
1334
1335 ieee80211_prepare_scan_chandef(&chandef);
1336
1337 ret = ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1338 &sched_scan_ies, req->ie,
1339 req->ie_len, bands_used, rate_masks,
1340 &chandef, flags);
1341 if (ret < 0)
1342 goto error;
1343
1344 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1345 if (ret == 0) {
1346 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1347 rcu_assign_pointer(local->sched_scan_req, req);
1348 }
1349
1350error:
1351 kfree(ie);
1352out:
1353 if (ret) {
1354 /* Clean in case of failure after HW restart or upon resume. */
1355 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1356 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1357 }
1358
1359 return ret;
1360}
1361
1362int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1363 struct cfg80211_sched_scan_request *req)
1364{
1365 struct ieee80211_local *local = sdata->local;
1366
1367 lockdep_assert_wiphy(local->hw.wiphy);
1368
1369 if (rcu_access_pointer(local->sched_scan_sdata))
1370 return -EBUSY;
1371
1372 return __ieee80211_request_sched_scan_start(sdata, req);
1373}
1374
1375int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1376{
1377 struct ieee80211_sub_if_data *sched_scan_sdata;
1378 int ret = -ENOENT;
1379
1380 lockdep_assert_wiphy(local->hw.wiphy);
1381
1382 if (!local->ops->sched_scan_stop)
1383 return -EOPNOTSUPP;
1384
1385 /* We don't want to restart sched scan anymore. */
1386 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1387
1388 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1389 lockdep_is_held(&local->hw.wiphy->mtx));
1390 if (sched_scan_sdata) {
1391 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1392 if (!ret)
1393 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1394 }
1395
1396 return ret;
1397}
1398
1399void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1400{
1401 struct ieee80211_local *local = hw_to_local(hw);
1402
1403 trace_api_sched_scan_results(local);
1404
1405 cfg80211_sched_scan_results(hw->wiphy, 0);
1406}
1407EXPORT_SYMBOL(ieee80211_sched_scan_results);
1408
1409void ieee80211_sched_scan_end(struct ieee80211_local *local)
1410{
1411 lockdep_assert_wiphy(local->hw.wiphy);
1412
1413 if (!rcu_access_pointer(local->sched_scan_sdata))
1414 return;
1415
1416 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1417
1418 /* If sched scan was aborted by the driver. */
1419 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1420
1421 cfg80211_sched_scan_stopped_locked(local->hw.wiphy, 0);
1422}
1423
1424void ieee80211_sched_scan_stopped_work(struct wiphy *wiphy,
1425 struct wiphy_work *work)
1426{
1427 struct ieee80211_local *local =
1428 container_of(work, struct ieee80211_local,
1429 sched_scan_stopped_work);
1430
1431 ieee80211_sched_scan_end(local);
1432}
1433
1434void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1435{
1436 struct ieee80211_local *local = hw_to_local(hw);
1437
1438 trace_api_sched_scan_stopped(local);
1439
1440 /*
1441 * this shouldn't really happen, so for simplicity
1442 * simply ignore it, and let mac80211 reconfigure
1443 * the sched scan later on.
1444 */
1445 if (local->in_reconfig)
1446 return;
1447
1448 wiphy_work_queue(hw->wiphy, &local->sched_scan_stopped_work);
1449}
1450EXPORT_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);