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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) 2018-2019 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 struct cfg80211_bss *cbss, *non_tx_cbss;
151 struct ieee80211_bss *bss, *non_tx_bss;
152 struct cfg80211_inform_bss bss_meta = {
153 .boottime_ns = rx_status->boottime_ns,
154 };
155 bool signal_valid;
156 struct ieee80211_sub_if_data *scan_sdata;
157 struct ieee802_11_elems elems;
158 size_t baselen;
159 u8 *elements;
160
161 if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
162 bss_meta.signal = 0; /* invalid signal indication */
163 else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
164 bss_meta.signal = rx_status->signal * 100;
165 else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
166 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
167
168 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
169 if (rx_status->bw == RATE_INFO_BW_5)
170 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
171 else if (rx_status->bw == RATE_INFO_BW_10)
172 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
173
174 bss_meta.chan = channel;
175
176 rcu_read_lock();
177 scan_sdata = rcu_dereference(local->scan_sdata);
178 if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
179 scan_sdata->vif.bss_conf.assoc &&
180 ieee80211_have_rx_timestamp(rx_status)) {
181 bss_meta.parent_tsf =
182 ieee80211_calculate_rx_timestamp(local, rx_status,
183 len + FCS_LEN, 24);
184 ether_addr_copy(bss_meta.parent_bssid,
185 scan_sdata->vif.bss_conf.bssid);
186 }
187 rcu_read_unlock();
188
189 cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
190 mgmt, len, GFP_ATOMIC);
191 if (!cbss)
192 return NULL;
193
194 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
195 elements = mgmt->u.probe_resp.variable;
196 baselen = offsetof(struct ieee80211_mgmt,
197 u.probe_resp.variable);
198 } else {
199 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
200 elements = mgmt->u.beacon.variable;
201 }
202
203 if (baselen > len)
204 return NULL;
205
206 ieee802_11_parse_elems(elements, len - baselen, false, &elems,
207 mgmt->bssid, cbss->bssid);
208
209 /* In case the signal is invalid update the status */
210 signal_valid = channel == cbss->channel;
211 if (!signal_valid)
212 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
213
214 bss = (void *)cbss->priv;
215 ieee80211_update_bss_from_elems(local, bss, &elems, rx_status, beacon);
216
217 list_for_each_entry(non_tx_cbss, &cbss->nontrans_list, nontrans_list) {
218 non_tx_bss = (void *)non_tx_cbss->priv;
219
220 ieee80211_update_bss_from_elems(local, non_tx_bss, &elems,
221 rx_status, beacon);
222 }
223
224 return bss;
225}
226
227static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
228 u32 scan_flags, const u8 *da)
229{
230 if (!sdata)
231 return false;
232 /* accept broadcast for OCE */
233 if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
234 is_broadcast_ether_addr(da))
235 return true;
236 if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
237 return true;
238 return ether_addr_equal(da, sdata->vif.addr);
239}
240
241void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
242{
243 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
244 struct ieee80211_sub_if_data *sdata1, *sdata2;
245 struct ieee80211_mgmt *mgmt = (void *)skb->data;
246 struct ieee80211_bss *bss;
247 struct ieee80211_channel *channel;
248
249 if (skb->len < 24 ||
250 (!ieee80211_is_probe_resp(mgmt->frame_control) &&
251 !ieee80211_is_beacon(mgmt->frame_control)))
252 return;
253
254 sdata1 = rcu_dereference(local->scan_sdata);
255 sdata2 = rcu_dereference(local->sched_scan_sdata);
256
257 if (likely(!sdata1 && !sdata2))
258 return;
259
260 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
261 struct cfg80211_scan_request *scan_req;
262 struct cfg80211_sched_scan_request *sched_scan_req;
263 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
264
265 scan_req = rcu_dereference(local->scan_req);
266 sched_scan_req = rcu_dereference(local->sched_scan_req);
267
268 if (scan_req)
269 scan_req_flags = scan_req->flags;
270
271 if (sched_scan_req)
272 sched_scan_req_flags = sched_scan_req->flags;
273
274 /* ignore ProbeResp to foreign address or non-bcast (OCE)
275 * unless scanning with randomised address
276 */
277 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
278 mgmt->da) &&
279 !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
280 mgmt->da))
281 return;
282 }
283
284 channel = ieee80211_get_channel_khz(local->hw.wiphy,
285 ieee80211_rx_status_to_khz(rx_status));
286
287 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
288 return;
289
290 bss = ieee80211_bss_info_update(local, rx_status,
291 mgmt, skb->len,
292 channel);
293 if (bss)
294 ieee80211_rx_bss_put(local, bss);
295}
296
297static void
298ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
299 enum nl80211_bss_scan_width scan_width)
300{
301 memset(chandef, 0, sizeof(*chandef));
302 switch (scan_width) {
303 case NL80211_BSS_CHAN_WIDTH_5:
304 chandef->width = NL80211_CHAN_WIDTH_5;
305 break;
306 case NL80211_BSS_CHAN_WIDTH_10:
307 chandef->width = NL80211_CHAN_WIDTH_10;
308 break;
309 default:
310 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
311 break;
312 }
313}
314
315/* return false if no more work */
316static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
317{
318 struct ieee80211_local *local = sdata->local;
319 struct cfg80211_scan_request *req;
320 struct cfg80211_chan_def chandef;
321 u8 bands_used = 0;
322 int i, ielen, n_chans;
323 u32 flags = 0;
324
325 req = rcu_dereference_protected(local->scan_req,
326 lockdep_is_held(&local->mtx));
327
328 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
329 return false;
330
331 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
332 for (i = 0; i < req->n_channels; i++) {
333 local->hw_scan_req->req.channels[i] = req->channels[i];
334 bands_used |= BIT(req->channels[i]->band);
335 }
336
337 n_chans = req->n_channels;
338 } else {
339 do {
340 if (local->hw_scan_band == NUM_NL80211_BANDS)
341 return false;
342
343 n_chans = 0;
344
345 for (i = 0; i < req->n_channels; i++) {
346 if (req->channels[i]->band !=
347 local->hw_scan_band)
348 continue;
349 local->hw_scan_req->req.channels[n_chans] =
350 req->channels[i];
351 n_chans++;
352 bands_used |= BIT(req->channels[i]->band);
353 }
354
355 local->hw_scan_band++;
356 } while (!n_chans);
357 }
358
359 local->hw_scan_req->req.n_channels = n_chans;
360 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
361
362 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
363 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
364
365 ielen = ieee80211_build_preq_ies(sdata,
366 (u8 *)local->hw_scan_req->req.ie,
367 local->hw_scan_ies_bufsize,
368 &local->hw_scan_req->ies,
369 req->ie, req->ie_len,
370 bands_used, req->rates, &chandef,
371 flags);
372 local->hw_scan_req->req.ie_len = ielen;
373 local->hw_scan_req->req.no_cck = req->no_cck;
374 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
375 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
376 req->mac_addr_mask);
377 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
378
379 return true;
380}
381
382static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
383{
384 struct ieee80211_local *local = hw_to_local(hw);
385 bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
386 bool was_scanning = local->scanning;
387 struct cfg80211_scan_request *scan_req;
388 struct ieee80211_sub_if_data *scan_sdata;
389 struct ieee80211_sub_if_data *sdata;
390
391 lockdep_assert_held(&local->mtx);
392
393 /*
394 * It's ok to abort a not-yet-running scan (that
395 * we have one at all will be verified by checking
396 * local->scan_req next), but not to complete it
397 * successfully.
398 */
399 if (WARN_ON(!local->scanning && !aborted))
400 aborted = true;
401
402 if (WARN_ON(!local->scan_req))
403 return;
404
405 scan_sdata = rcu_dereference_protected(local->scan_sdata,
406 lockdep_is_held(&local->mtx));
407
408 if (hw_scan && !aborted &&
409 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
410 ieee80211_prep_hw_scan(scan_sdata)) {
411 int rc;
412
413 rc = drv_hw_scan(local,
414 rcu_dereference_protected(local->scan_sdata,
415 lockdep_is_held(&local->mtx)),
416 local->hw_scan_req);
417
418 if (rc == 0)
419 return;
420
421 /* HW scan failed and is going to be reported as aborted,
422 * so clear old scan info.
423 */
424 memset(&local->scan_info, 0, sizeof(local->scan_info));
425 aborted = true;
426 }
427
428 kfree(local->hw_scan_req);
429 local->hw_scan_req = NULL;
430
431 scan_req = rcu_dereference_protected(local->scan_req,
432 lockdep_is_held(&local->mtx));
433
434 if (scan_req != local->int_scan_req) {
435 local->scan_info.aborted = aborted;
436 cfg80211_scan_done(scan_req, &local->scan_info);
437 }
438 RCU_INIT_POINTER(local->scan_req, NULL);
439 RCU_INIT_POINTER(local->scan_sdata, NULL);
440
441 local->scanning = 0;
442 local->scan_chandef.chan = NULL;
443
444 /* Set power back to normal operating levels. */
445 ieee80211_hw_config(local, 0);
446
447 if (!hw_scan) {
448 ieee80211_configure_filter(local);
449 drv_sw_scan_complete(local, scan_sdata);
450 ieee80211_offchannel_return(local);
451 }
452
453 ieee80211_recalc_idle(local);
454
455 ieee80211_mlme_notify_scan_completed(local);
456 ieee80211_ibss_notify_scan_completed(local);
457
458 /* Requeue all the work that might have been ignored while
459 * the scan was in progress; if there was none this will
460 * just be a no-op for the particular interface.
461 */
462 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
463 if (ieee80211_sdata_running(sdata))
464 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
465 }
466
467 if (was_scanning)
468 ieee80211_start_next_roc(local);
469}
470
471void ieee80211_scan_completed(struct ieee80211_hw *hw,
472 struct cfg80211_scan_info *info)
473{
474 struct ieee80211_local *local = hw_to_local(hw);
475
476 trace_api_scan_completed(local, info->aborted);
477
478 set_bit(SCAN_COMPLETED, &local->scanning);
479 if (info->aborted)
480 set_bit(SCAN_ABORTED, &local->scanning);
481
482 memcpy(&local->scan_info, info, sizeof(*info));
483
484 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
485}
486EXPORT_SYMBOL(ieee80211_scan_completed);
487
488static int ieee80211_start_sw_scan(struct ieee80211_local *local,
489 struct ieee80211_sub_if_data *sdata)
490{
491 /* Software scan is not supported in multi-channel cases */
492 if (local->use_chanctx)
493 return -EOPNOTSUPP;
494
495 /*
496 * Hardware/driver doesn't support hw_scan, so use software
497 * scanning instead. First send a nullfunc frame with power save
498 * bit on so that AP will buffer the frames for us while we are not
499 * listening, then send probe requests to each channel and wait for
500 * the responses. After all channels are scanned, tune back to the
501 * original channel and send a nullfunc frame with power save bit
502 * off to trigger the AP to send us all the buffered frames.
503 *
504 * Note that while local->sw_scanning is true everything else but
505 * nullfunc frames and probe requests will be dropped in
506 * ieee80211_tx_h_check_assoc().
507 */
508 drv_sw_scan_start(local, sdata, local->scan_addr);
509
510 local->leave_oper_channel_time = jiffies;
511 local->next_scan_state = SCAN_DECISION;
512 local->scan_channel_idx = 0;
513
514 ieee80211_offchannel_stop_vifs(local);
515
516 /* ensure nullfunc is transmitted before leaving operating channel */
517 ieee80211_flush_queues(local, NULL, false);
518
519 ieee80211_configure_filter(local);
520
521 /* We need to set power level at maximum rate for scanning. */
522 ieee80211_hw_config(local, 0);
523
524 ieee80211_queue_delayed_work(&local->hw,
525 &local->scan_work, 0);
526
527 return 0;
528}
529
530static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
531{
532 struct ieee80211_local *local = sdata->local;
533 struct ieee80211_sub_if_data *sdata_iter;
534
535 if (!ieee80211_is_radar_required(local))
536 return true;
537
538 if (!regulatory_pre_cac_allowed(local->hw.wiphy))
539 return false;
540
541 mutex_lock(&local->iflist_mtx);
542 list_for_each_entry(sdata_iter, &local->interfaces, list) {
543 if (sdata_iter->wdev.cac_started) {
544 mutex_unlock(&local->iflist_mtx);
545 return false;
546 }
547 }
548 mutex_unlock(&local->iflist_mtx);
549
550 return true;
551}
552
553static bool ieee80211_can_scan(struct ieee80211_local *local,
554 struct ieee80211_sub_if_data *sdata)
555{
556 if (!__ieee80211_can_leave_ch(sdata))
557 return false;
558
559 if (!list_empty(&local->roc_list))
560 return false;
561
562 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
563 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
564 return false;
565
566 return true;
567}
568
569void ieee80211_run_deferred_scan(struct ieee80211_local *local)
570{
571 lockdep_assert_held(&local->mtx);
572
573 if (!local->scan_req || local->scanning)
574 return;
575
576 if (!ieee80211_can_scan(local,
577 rcu_dereference_protected(
578 local->scan_sdata,
579 lockdep_is_held(&local->mtx))))
580 return;
581
582 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
583 round_jiffies_relative(0));
584}
585
586static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
587 const u8 *src, const u8 *dst,
588 const u8 *ssid, size_t ssid_len,
589 const u8 *ie, size_t ie_len,
590 u32 ratemask, u32 flags, u32 tx_flags,
591 struct ieee80211_channel *channel)
592{
593 struct sk_buff *skb;
594
595 skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
596 ssid, ssid_len,
597 ie, ie_len, flags);
598
599 if (skb) {
600 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
601 struct ieee80211_hdr *hdr = (void *)skb->data;
602 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
603 u16 sn = get_random_u32();
604
605 info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
606 hdr->seq_ctrl =
607 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
608 }
609 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
610 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
611 }
612}
613
614static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
615 unsigned long *next_delay)
616{
617 int i;
618 struct ieee80211_sub_if_data *sdata;
619 struct cfg80211_scan_request *scan_req;
620 enum nl80211_band band = local->hw.conf.chandef.chan->band;
621 u32 flags = 0, tx_flags;
622
623 scan_req = rcu_dereference_protected(local->scan_req,
624 lockdep_is_held(&local->mtx));
625
626 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
627 if (scan_req->no_cck)
628 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
629 if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
630 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
631 if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
632 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
633
634 sdata = rcu_dereference_protected(local->scan_sdata,
635 lockdep_is_held(&local->mtx));
636
637 for (i = 0; i < scan_req->n_ssids; i++)
638 ieee80211_send_scan_probe_req(
639 sdata, local->scan_addr, scan_req->bssid,
640 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
641 scan_req->ie, scan_req->ie_len,
642 scan_req->rates[band], flags,
643 tx_flags, local->hw.conf.chandef.chan);
644
645 /*
646 * After sending probe requests, wait for probe responses
647 * on the channel.
648 */
649 *next_delay = IEEE80211_CHANNEL_TIME;
650 local->next_scan_state = SCAN_DECISION;
651}
652
653static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
654 struct cfg80211_scan_request *req)
655{
656 struct ieee80211_local *local = sdata->local;
657 bool hw_scan = local->ops->hw_scan;
658 int rc;
659
660 lockdep_assert_held(&local->mtx);
661
662 if (local->scan_req)
663 return -EBUSY;
664
665 if (!__ieee80211_can_leave_ch(sdata))
666 return -EBUSY;
667
668 if (!ieee80211_can_scan(local, sdata)) {
669 /* wait for the work to finish/time out */
670 rcu_assign_pointer(local->scan_req, req);
671 rcu_assign_pointer(local->scan_sdata, sdata);
672 return 0;
673 }
674
675 again:
676 if (hw_scan) {
677 u8 *ies;
678
679 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
680
681 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
682 int i, n_bands = 0;
683 u8 bands_counted = 0;
684
685 for (i = 0; i < req->n_channels; i++) {
686 if (bands_counted & BIT(req->channels[i]->band))
687 continue;
688 bands_counted |= BIT(req->channels[i]->band);
689 n_bands++;
690 }
691
692 local->hw_scan_ies_bufsize *= n_bands;
693 }
694
695 local->hw_scan_req = kmalloc(
696 sizeof(*local->hw_scan_req) +
697 req->n_channels * sizeof(req->channels[0]) +
698 local->hw_scan_ies_bufsize, GFP_KERNEL);
699 if (!local->hw_scan_req)
700 return -ENOMEM;
701
702 local->hw_scan_req->req.ssids = req->ssids;
703 local->hw_scan_req->req.n_ssids = req->n_ssids;
704 ies = (u8 *)local->hw_scan_req +
705 sizeof(*local->hw_scan_req) +
706 req->n_channels * sizeof(req->channels[0]);
707 local->hw_scan_req->req.ie = ies;
708 local->hw_scan_req->req.flags = req->flags;
709 eth_broadcast_addr(local->hw_scan_req->req.bssid);
710 local->hw_scan_req->req.duration = req->duration;
711 local->hw_scan_req->req.duration_mandatory =
712 req->duration_mandatory;
713
714 local->hw_scan_band = 0;
715
716 /*
717 * After allocating local->hw_scan_req, we must
718 * go through until ieee80211_prep_hw_scan(), so
719 * anything that might be changed here and leave
720 * this function early must not go after this
721 * allocation.
722 */
723 }
724
725 rcu_assign_pointer(local->scan_req, req);
726 rcu_assign_pointer(local->scan_sdata, sdata);
727
728 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
729 get_random_mask_addr(local->scan_addr,
730 req->mac_addr,
731 req->mac_addr_mask);
732 else
733 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
734
735 if (hw_scan) {
736 __set_bit(SCAN_HW_SCANNING, &local->scanning);
737 } else if ((req->n_channels == 1) &&
738 (req->channels[0] == local->_oper_chandef.chan)) {
739 /*
740 * If we are scanning only on the operating channel
741 * then we do not need to stop normal activities
742 */
743 unsigned long next_delay;
744
745 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
746
747 ieee80211_recalc_idle(local);
748
749 /* Notify driver scan is starting, keep order of operations
750 * same as normal software scan, in case that matters. */
751 drv_sw_scan_start(local, sdata, local->scan_addr);
752
753 ieee80211_configure_filter(local); /* accept probe-responses */
754
755 /* We need to ensure power level is at max for scanning. */
756 ieee80211_hw_config(local, 0);
757
758 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
759 IEEE80211_CHAN_RADAR)) ||
760 !req->n_ssids) {
761 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
762 } else {
763 ieee80211_scan_state_send_probe(local, &next_delay);
764 next_delay = IEEE80211_CHANNEL_TIME;
765 }
766
767 /* Now, just wait a bit and we are all done! */
768 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
769 next_delay);
770 return 0;
771 } else {
772 /* Do normal software scan */
773 __set_bit(SCAN_SW_SCANNING, &local->scanning);
774 }
775
776 ieee80211_recalc_idle(local);
777
778 if (hw_scan) {
779 WARN_ON(!ieee80211_prep_hw_scan(sdata));
780 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
781 } else {
782 rc = ieee80211_start_sw_scan(local, sdata);
783 }
784
785 if (rc) {
786 kfree(local->hw_scan_req);
787 local->hw_scan_req = NULL;
788 local->scanning = 0;
789
790 ieee80211_recalc_idle(local);
791
792 local->scan_req = NULL;
793 RCU_INIT_POINTER(local->scan_sdata, NULL);
794 }
795
796 if (hw_scan && rc == 1) {
797 /*
798 * we can't fall back to software for P2P-GO
799 * as it must update NoA etc.
800 */
801 if (ieee80211_vif_type_p2p(&sdata->vif) ==
802 NL80211_IFTYPE_P2P_GO)
803 return -EOPNOTSUPP;
804 hw_scan = false;
805 goto again;
806 }
807
808 return rc;
809}
810
811static unsigned long
812ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
813{
814 /*
815 * TODO: channel switching also consumes quite some time,
816 * add that delay as well to get a better estimation
817 */
818 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
819 return IEEE80211_PASSIVE_CHANNEL_TIME;
820 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
821}
822
823static void ieee80211_scan_state_decision(struct ieee80211_local *local,
824 unsigned long *next_delay)
825{
826 bool associated = false;
827 bool tx_empty = true;
828 bool bad_latency;
829 struct ieee80211_sub_if_data *sdata;
830 struct ieee80211_channel *next_chan;
831 enum mac80211_scan_state next_scan_state;
832 struct cfg80211_scan_request *scan_req;
833
834 /*
835 * check if at least one STA interface is associated,
836 * check if at least one STA interface has pending tx frames
837 * and grab the lowest used beacon interval
838 */
839 mutex_lock(&local->iflist_mtx);
840 list_for_each_entry(sdata, &local->interfaces, list) {
841 if (!ieee80211_sdata_running(sdata))
842 continue;
843
844 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
845 if (sdata->u.mgd.associated) {
846 associated = true;
847
848 if (!qdisc_all_tx_empty(sdata->dev)) {
849 tx_empty = false;
850 break;
851 }
852 }
853 }
854 }
855 mutex_unlock(&local->iflist_mtx);
856
857 scan_req = rcu_dereference_protected(local->scan_req,
858 lockdep_is_held(&local->mtx));
859
860 next_chan = scan_req->channels[local->scan_channel_idx];
861
862 /*
863 * we're currently scanning a different channel, let's
864 * see if we can scan another channel without interfering
865 * with the current traffic situation.
866 *
867 * Keep good latency, do not stay off-channel more than 125 ms.
868 */
869
870 bad_latency = time_after(jiffies +
871 ieee80211_scan_get_channel_time(next_chan),
872 local->leave_oper_channel_time + HZ / 8);
873
874 if (associated && !tx_empty) {
875 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
876 next_scan_state = SCAN_ABORT;
877 else
878 next_scan_state = SCAN_SUSPEND;
879 } else if (associated && bad_latency) {
880 next_scan_state = SCAN_SUSPEND;
881 } else {
882 next_scan_state = SCAN_SET_CHANNEL;
883 }
884
885 local->next_scan_state = next_scan_state;
886
887 *next_delay = 0;
888}
889
890static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
891 unsigned long *next_delay)
892{
893 int skip;
894 struct ieee80211_channel *chan;
895 enum nl80211_bss_scan_width oper_scan_width;
896 struct cfg80211_scan_request *scan_req;
897
898 scan_req = rcu_dereference_protected(local->scan_req,
899 lockdep_is_held(&local->mtx));
900
901 skip = 0;
902 chan = scan_req->channels[local->scan_channel_idx];
903
904 local->scan_chandef.chan = chan;
905 local->scan_chandef.center_freq1 = chan->center_freq;
906 local->scan_chandef.freq1_offset = chan->freq_offset;
907 local->scan_chandef.center_freq2 = 0;
908 switch (scan_req->scan_width) {
909 case NL80211_BSS_CHAN_WIDTH_5:
910 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
911 break;
912 case NL80211_BSS_CHAN_WIDTH_10:
913 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
914 break;
915 default:
916 case NL80211_BSS_CHAN_WIDTH_20:
917 /* If scanning on oper channel, use whatever channel-type
918 * is currently in use.
919 */
920 oper_scan_width = cfg80211_chandef_to_scan_width(
921 &local->_oper_chandef);
922 if (chan == local->_oper_chandef.chan &&
923 oper_scan_width == scan_req->scan_width)
924 local->scan_chandef = local->_oper_chandef;
925 else
926 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
927 break;
928 }
929
930 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
931 skip = 1;
932
933 /* advance state machine to next channel/band */
934 local->scan_channel_idx++;
935
936 if (skip) {
937 /* if we skip this channel return to the decision state */
938 local->next_scan_state = SCAN_DECISION;
939 return;
940 }
941
942 /*
943 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
944 * (which unfortunately doesn't say _why_ step a) is done,
945 * but it waits for the probe delay or until a frame is
946 * received - and the received frame would update the NAV).
947 * For now, we do not support waiting until a frame is
948 * received.
949 *
950 * In any case, it is not necessary for a passive scan.
951 */
952 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
953 !scan_req->n_ssids) {
954 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
955 local->next_scan_state = SCAN_DECISION;
956 return;
957 }
958
959 /* active scan, send probes */
960 *next_delay = IEEE80211_PROBE_DELAY;
961 local->next_scan_state = SCAN_SEND_PROBE;
962}
963
964static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
965 unsigned long *next_delay)
966{
967 /* switch back to the operating channel */
968 local->scan_chandef.chan = NULL;
969 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
970
971 /* disable PS */
972 ieee80211_offchannel_return(local);
973
974 *next_delay = HZ / 5;
975 /* afterwards, resume scan & go to next channel */
976 local->next_scan_state = SCAN_RESUME;
977}
978
979static void ieee80211_scan_state_resume(struct ieee80211_local *local,
980 unsigned long *next_delay)
981{
982 ieee80211_offchannel_stop_vifs(local);
983
984 if (local->ops->flush) {
985 ieee80211_flush_queues(local, NULL, false);
986 *next_delay = 0;
987 } else
988 *next_delay = HZ / 10;
989
990 /* remember when we left the operating channel */
991 local->leave_oper_channel_time = jiffies;
992
993 /* advance to the next channel to be scanned */
994 local->next_scan_state = SCAN_SET_CHANNEL;
995}
996
997void ieee80211_scan_work(struct work_struct *work)
998{
999 struct ieee80211_local *local =
1000 container_of(work, struct ieee80211_local, scan_work.work);
1001 struct ieee80211_sub_if_data *sdata;
1002 struct cfg80211_scan_request *scan_req;
1003 unsigned long next_delay = 0;
1004 bool aborted;
1005
1006 mutex_lock(&local->mtx);
1007
1008 if (!ieee80211_can_run_worker(local)) {
1009 aborted = true;
1010 goto out_complete;
1011 }
1012
1013 sdata = rcu_dereference_protected(local->scan_sdata,
1014 lockdep_is_held(&local->mtx));
1015 scan_req = rcu_dereference_protected(local->scan_req,
1016 lockdep_is_held(&local->mtx));
1017
1018 /* When scanning on-channel, the first-callback means completed. */
1019 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1020 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1021 goto out_complete;
1022 }
1023
1024 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1025 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1026 goto out_complete;
1027 }
1028
1029 if (!sdata || !scan_req)
1030 goto out;
1031
1032 if (!local->scanning) {
1033 int rc;
1034
1035 RCU_INIT_POINTER(local->scan_req, NULL);
1036 RCU_INIT_POINTER(local->scan_sdata, NULL);
1037
1038 rc = __ieee80211_start_scan(sdata, scan_req);
1039 if (rc) {
1040 /* need to complete scan in cfg80211 */
1041 rcu_assign_pointer(local->scan_req, scan_req);
1042 aborted = true;
1043 goto out_complete;
1044 } else
1045 goto out;
1046 }
1047
1048 /*
1049 * as long as no delay is required advance immediately
1050 * without scheduling a new work
1051 */
1052 do {
1053 if (!ieee80211_sdata_running(sdata)) {
1054 aborted = true;
1055 goto out_complete;
1056 }
1057
1058 switch (local->next_scan_state) {
1059 case SCAN_DECISION:
1060 /* if no more bands/channels left, complete scan */
1061 if (local->scan_channel_idx >= scan_req->n_channels) {
1062 aborted = false;
1063 goto out_complete;
1064 }
1065 ieee80211_scan_state_decision(local, &next_delay);
1066 break;
1067 case SCAN_SET_CHANNEL:
1068 ieee80211_scan_state_set_channel(local, &next_delay);
1069 break;
1070 case SCAN_SEND_PROBE:
1071 ieee80211_scan_state_send_probe(local, &next_delay);
1072 break;
1073 case SCAN_SUSPEND:
1074 ieee80211_scan_state_suspend(local, &next_delay);
1075 break;
1076 case SCAN_RESUME:
1077 ieee80211_scan_state_resume(local, &next_delay);
1078 break;
1079 case SCAN_ABORT:
1080 aborted = true;
1081 goto out_complete;
1082 }
1083 } while (next_delay == 0);
1084
1085 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
1086 goto out;
1087
1088out_complete:
1089 __ieee80211_scan_completed(&local->hw, aborted);
1090out:
1091 mutex_unlock(&local->mtx);
1092}
1093
1094int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1095 struct cfg80211_scan_request *req)
1096{
1097 int res;
1098
1099 mutex_lock(&sdata->local->mtx);
1100 res = __ieee80211_start_scan(sdata, req);
1101 mutex_unlock(&sdata->local->mtx);
1102
1103 return res;
1104}
1105
1106int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1107 const u8 *ssid, u8 ssid_len,
1108 struct ieee80211_channel **channels,
1109 unsigned int n_channels,
1110 enum nl80211_bss_scan_width scan_width)
1111{
1112 struct ieee80211_local *local = sdata->local;
1113 int ret = -EBUSY, i, n_ch = 0;
1114 enum nl80211_band band;
1115
1116 mutex_lock(&local->mtx);
1117
1118 /* busy scanning */
1119 if (local->scan_req)
1120 goto unlock;
1121
1122 /* fill internal scan request */
1123 if (!channels) {
1124 int max_n;
1125
1126 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1127 if (!local->hw.wiphy->bands[band])
1128 continue;
1129
1130 max_n = local->hw.wiphy->bands[band]->n_channels;
1131 for (i = 0; i < max_n; i++) {
1132 struct ieee80211_channel *tmp_ch =
1133 &local->hw.wiphy->bands[band]->channels[i];
1134
1135 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1136 IEEE80211_CHAN_DISABLED))
1137 continue;
1138
1139 local->int_scan_req->channels[n_ch] = tmp_ch;
1140 n_ch++;
1141 }
1142 }
1143
1144 if (WARN_ON_ONCE(n_ch == 0))
1145 goto unlock;
1146
1147 local->int_scan_req->n_channels = n_ch;
1148 } else {
1149 for (i = 0; i < n_channels; i++) {
1150 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1151 IEEE80211_CHAN_DISABLED))
1152 continue;
1153
1154 local->int_scan_req->channels[n_ch] = channels[i];
1155 n_ch++;
1156 }
1157
1158 if (WARN_ON_ONCE(n_ch == 0))
1159 goto unlock;
1160
1161 local->int_scan_req->n_channels = n_ch;
1162 }
1163
1164 local->int_scan_req->ssids = &local->scan_ssid;
1165 local->int_scan_req->n_ssids = 1;
1166 local->int_scan_req->scan_width = scan_width;
1167 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1168 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1169
1170 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1171 unlock:
1172 mutex_unlock(&local->mtx);
1173 return ret;
1174}
1175
1176/*
1177 * Only call this function when a scan can't be queued -- under RTNL.
1178 */
1179void ieee80211_scan_cancel(struct ieee80211_local *local)
1180{
1181 /*
1182 * We are canceling software scan, or deferred scan that was not
1183 * yet really started (see __ieee80211_start_scan ).
1184 *
1185 * Regarding hardware scan:
1186 * - we can not call __ieee80211_scan_completed() as when
1187 * SCAN_HW_SCANNING bit is set this function change
1188 * local->hw_scan_req to operate on 5G band, what race with
1189 * driver which can use local->hw_scan_req
1190 *
1191 * - we can not cancel scan_work since driver can schedule it
1192 * by ieee80211_scan_completed(..., true) to finish scan
1193 *
1194 * Hence we only call the cancel_hw_scan() callback, but the low-level
1195 * driver is still responsible for calling ieee80211_scan_completed()
1196 * after the scan was completed/aborted.
1197 */
1198
1199 mutex_lock(&local->mtx);
1200 if (!local->scan_req)
1201 goto out;
1202
1203 /*
1204 * We have a scan running and the driver already reported completion,
1205 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1206 * cancelled.
1207 */
1208 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1209 test_bit(SCAN_COMPLETED, &local->scanning)) {
1210 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1211 goto out;
1212 }
1213
1214 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1215 /*
1216 * Make sure that __ieee80211_scan_completed doesn't trigger a
1217 * scan on another band.
1218 */
1219 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1220 if (local->ops->cancel_hw_scan)
1221 drv_cancel_hw_scan(local,
1222 rcu_dereference_protected(local->scan_sdata,
1223 lockdep_is_held(&local->mtx)));
1224 goto out;
1225 }
1226
1227 /*
1228 * If the work is currently running, it must be blocked on
1229 * the mutex, but we'll set scan_sdata = NULL and it'll
1230 * simply exit once it acquires the mutex.
1231 */
1232 cancel_delayed_work(&local->scan_work);
1233 /* and clean up */
1234 memset(&local->scan_info, 0, sizeof(local->scan_info));
1235 __ieee80211_scan_completed(&local->hw, true);
1236out:
1237 mutex_unlock(&local->mtx);
1238}
1239
1240int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1241 struct cfg80211_sched_scan_request *req)
1242{
1243 struct ieee80211_local *local = sdata->local;
1244 struct ieee80211_scan_ies sched_scan_ies = {};
1245 struct cfg80211_chan_def chandef;
1246 int ret, i, iebufsz, num_bands = 0;
1247 u32 rate_masks[NUM_NL80211_BANDS] = {};
1248 u8 bands_used = 0;
1249 u8 *ie;
1250 u32 flags = 0;
1251
1252 iebufsz = local->scan_ies_len + req->ie_len;
1253
1254 lockdep_assert_held(&local->mtx);
1255
1256 if (!local->ops->sched_scan_start)
1257 return -ENOTSUPP;
1258
1259 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1260 if (local->hw.wiphy->bands[i]) {
1261 bands_used |= BIT(i);
1262 rate_masks[i] = (u32) -1;
1263 num_bands++;
1264 }
1265 }
1266
1267 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1268 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1269
1270 ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1271 if (!ie) {
1272 ret = -ENOMEM;
1273 goto out;
1274 }
1275
1276 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1277
1278 ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1279 &sched_scan_ies, req->ie,
1280 req->ie_len, bands_used, rate_masks, &chandef,
1281 flags);
1282
1283 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1284 if (ret == 0) {
1285 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1286 rcu_assign_pointer(local->sched_scan_req, req);
1287 }
1288
1289 kfree(ie);
1290
1291out:
1292 if (ret) {
1293 /* Clean in case of failure after HW restart or upon resume. */
1294 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1295 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1296 }
1297
1298 return ret;
1299}
1300
1301int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1302 struct cfg80211_sched_scan_request *req)
1303{
1304 struct ieee80211_local *local = sdata->local;
1305 int ret;
1306
1307 mutex_lock(&local->mtx);
1308
1309 if (rcu_access_pointer(local->sched_scan_sdata)) {
1310 mutex_unlock(&local->mtx);
1311 return -EBUSY;
1312 }
1313
1314 ret = __ieee80211_request_sched_scan_start(sdata, req);
1315
1316 mutex_unlock(&local->mtx);
1317 return ret;
1318}
1319
1320int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1321{
1322 struct ieee80211_sub_if_data *sched_scan_sdata;
1323 int ret = -ENOENT;
1324
1325 mutex_lock(&local->mtx);
1326
1327 if (!local->ops->sched_scan_stop) {
1328 ret = -ENOTSUPP;
1329 goto out;
1330 }
1331
1332 /* We don't want to restart sched scan anymore. */
1333 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1334
1335 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1336 lockdep_is_held(&local->mtx));
1337 if (sched_scan_sdata) {
1338 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1339 if (!ret)
1340 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1341 }
1342out:
1343 mutex_unlock(&local->mtx);
1344
1345 return ret;
1346}
1347
1348void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1349{
1350 struct ieee80211_local *local = hw_to_local(hw);
1351
1352 trace_api_sched_scan_results(local);
1353
1354 cfg80211_sched_scan_results(hw->wiphy, 0);
1355}
1356EXPORT_SYMBOL(ieee80211_sched_scan_results);
1357
1358void ieee80211_sched_scan_end(struct ieee80211_local *local)
1359{
1360 mutex_lock(&local->mtx);
1361
1362 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1363 mutex_unlock(&local->mtx);
1364 return;
1365 }
1366
1367 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1368
1369 /* If sched scan was aborted by the driver. */
1370 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1371
1372 mutex_unlock(&local->mtx);
1373
1374 cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1375}
1376
1377void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1378{
1379 struct ieee80211_local *local =
1380 container_of(work, struct ieee80211_local,
1381 sched_scan_stopped_work);
1382
1383 ieee80211_sched_scan_end(local);
1384}
1385
1386void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1387{
1388 struct ieee80211_local *local = hw_to_local(hw);
1389
1390 trace_api_sched_scan_stopped(local);
1391
1392 /*
1393 * this shouldn't really happen, so for simplicity
1394 * simply ignore it, and let mac80211 reconfigure
1395 * the sched scan later on.
1396 */
1397 if (local->in_reconfig)
1398 return;
1399
1400 schedule_work(&local->sched_scan_stopped_work);
1401}
1402EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
1/*
2 * Scanning implementation
3 *
4 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
5 * Copyright 2004, Instant802 Networks, Inc.
6 * Copyright 2005, Devicescape Software, Inc.
7 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
8 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 */
14
15#include <linux/if_arp.h>
16#include <linux/etherdevice.h>
17#include <linux/rtnetlink.h>
18#include <linux/pm_qos.h>
19#include <net/sch_generic.h>
20#include <linux/slab.h>
21#include <linux/export.h>
22#include <net/mac80211.h>
23
24#include "ieee80211_i.h"
25#include "driver-ops.h"
26#include "mesh.h"
27
28#define IEEE80211_PROBE_DELAY (HZ / 33)
29#define IEEE80211_CHANNEL_TIME (HZ / 33)
30#define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 8)
31
32static void ieee80211_rx_bss_free(struct cfg80211_bss *cbss)
33{
34 struct ieee80211_bss *bss = (void *)cbss->priv;
35
36 kfree(bss_mesh_id(bss));
37 kfree(bss_mesh_cfg(bss));
38}
39
40void ieee80211_rx_bss_put(struct ieee80211_local *local,
41 struct ieee80211_bss *bss)
42{
43 if (!bss)
44 return;
45 cfg80211_put_bss(container_of((void *)bss, struct cfg80211_bss, priv));
46}
47
48static bool is_uapsd_supported(struct ieee802_11_elems *elems)
49{
50 u8 qos_info;
51
52 if (elems->wmm_info && elems->wmm_info_len == 7
53 && elems->wmm_info[5] == 1)
54 qos_info = elems->wmm_info[6];
55 else if (elems->wmm_param && elems->wmm_param_len == 24
56 && elems->wmm_param[5] == 1)
57 qos_info = elems->wmm_param[6];
58 else
59 /* no valid wmm information or parameter element found */
60 return false;
61
62 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
63}
64
65struct ieee80211_bss *
66ieee80211_bss_info_update(struct ieee80211_local *local,
67 struct ieee80211_rx_status *rx_status,
68 struct ieee80211_mgmt *mgmt,
69 size_t len,
70 struct ieee802_11_elems *elems,
71 struct ieee80211_channel *channel,
72 bool beacon)
73{
74 struct cfg80211_bss *cbss;
75 struct ieee80211_bss *bss;
76 int clen, srlen;
77 s32 signal = 0;
78
79 if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
80 signal = rx_status->signal * 100;
81 else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC)
82 signal = (rx_status->signal * 100) / local->hw.max_signal;
83
84 cbss = cfg80211_inform_bss_frame(local->hw.wiphy, channel,
85 mgmt, len, signal, GFP_ATOMIC);
86
87 if (!cbss)
88 return NULL;
89
90 cbss->free_priv = ieee80211_rx_bss_free;
91 bss = (void *)cbss->priv;
92
93 if (elems->parse_error) {
94 if (beacon)
95 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
96 else
97 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
98 } else {
99 if (beacon)
100 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
101 else
102 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
103 }
104
105 /* save the ERP value so that it is available at association time */
106 if (elems->erp_info && elems->erp_info_len >= 1 &&
107 (!elems->parse_error ||
108 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
109 bss->erp_value = elems->erp_info[0];
110 bss->has_erp_value = true;
111 if (!elems->parse_error)
112 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
113 }
114
115 if (elems->tim && (!elems->parse_error ||
116 !(bss->valid_data & IEEE80211_BSS_VALID_DTIM))) {
117 struct ieee80211_tim_ie *tim_ie =
118 (struct ieee80211_tim_ie *)elems->tim;
119 bss->dtim_period = tim_ie->dtim_period;
120 if (!elems->parse_error)
121 bss->valid_data |= IEEE80211_BSS_VALID_DTIM;
122 }
123
124 /* If the beacon had no TIM IE, or it was invalid, use 1 */
125 if (beacon && !bss->dtim_period)
126 bss->dtim_period = 1;
127
128 /* replace old supported rates if we get new values */
129 if (!elems->parse_error ||
130 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
131 srlen = 0;
132 if (elems->supp_rates) {
133 clen = IEEE80211_MAX_SUPP_RATES;
134 if (clen > elems->supp_rates_len)
135 clen = elems->supp_rates_len;
136 memcpy(bss->supp_rates, elems->supp_rates, clen);
137 srlen += clen;
138 }
139 if (elems->ext_supp_rates) {
140 clen = IEEE80211_MAX_SUPP_RATES - srlen;
141 if (clen > elems->ext_supp_rates_len)
142 clen = elems->ext_supp_rates_len;
143 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
144 clen);
145 srlen += clen;
146 }
147 if (srlen) {
148 bss->supp_rates_len = srlen;
149 if (!elems->parse_error)
150 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
151 }
152 }
153
154 if (!elems->parse_error ||
155 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
156 bss->wmm_used = elems->wmm_param || elems->wmm_info;
157 bss->uapsd_supported = is_uapsd_supported(elems);
158 if (!elems->parse_error)
159 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
160 }
161
162 if (!beacon)
163 bss->last_probe_resp = jiffies;
164
165 return bss;
166}
167
168ieee80211_rx_result
169ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
170{
171 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
172 struct ieee80211_mgmt *mgmt;
173 struct ieee80211_bss *bss;
174 u8 *elements;
175 struct ieee80211_channel *channel;
176 size_t baselen;
177 int freq;
178 __le16 fc;
179 bool presp, beacon = false;
180 struct ieee802_11_elems elems;
181
182 if (skb->len < 2)
183 return RX_DROP_UNUSABLE;
184
185 mgmt = (struct ieee80211_mgmt *) skb->data;
186 fc = mgmt->frame_control;
187
188 if (ieee80211_is_ctl(fc))
189 return RX_CONTINUE;
190
191 if (skb->len < 24)
192 return RX_CONTINUE;
193
194 presp = ieee80211_is_probe_resp(fc);
195 if (presp) {
196 /* ignore ProbeResp to foreign address */
197 if (!ether_addr_equal(mgmt->da, sdata->vif.addr))
198 return RX_DROP_MONITOR;
199
200 presp = true;
201 elements = mgmt->u.probe_resp.variable;
202 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
203 } else {
204 beacon = ieee80211_is_beacon(fc);
205 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
206 elements = mgmt->u.beacon.variable;
207 }
208
209 if (!presp && !beacon)
210 return RX_CONTINUE;
211
212 if (baselen > skb->len)
213 return RX_DROP_MONITOR;
214
215 ieee802_11_parse_elems(elements, skb->len - baselen, &elems);
216
217 if (elems.ds_params && elems.ds_params_len == 1)
218 freq = ieee80211_channel_to_frequency(elems.ds_params[0],
219 rx_status->band);
220 else
221 freq = rx_status->freq;
222
223 channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq);
224
225 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
226 return RX_DROP_MONITOR;
227
228 bss = ieee80211_bss_info_update(sdata->local, rx_status,
229 mgmt, skb->len, &elems,
230 channel, beacon);
231 if (bss)
232 ieee80211_rx_bss_put(sdata->local, bss);
233
234 if (channel == sdata->local->oper_channel)
235 return RX_CONTINUE;
236
237 dev_kfree_skb(skb);
238 return RX_QUEUED;
239}
240
241/* return false if no more work */
242static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
243{
244 struct cfg80211_scan_request *req = local->scan_req;
245 enum ieee80211_band band;
246 int i, ielen, n_chans;
247
248 do {
249 if (local->hw_scan_band == IEEE80211_NUM_BANDS)
250 return false;
251
252 band = local->hw_scan_band;
253 n_chans = 0;
254 for (i = 0; i < req->n_channels; i++) {
255 if (req->channels[i]->band == band) {
256 local->hw_scan_req->channels[n_chans] =
257 req->channels[i];
258 n_chans++;
259 }
260 }
261
262 local->hw_scan_band++;
263 } while (!n_chans);
264
265 local->hw_scan_req->n_channels = n_chans;
266
267 ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie,
268 req->ie, req->ie_len, band,
269 req->rates[band], 0);
270 local->hw_scan_req->ie_len = ielen;
271 local->hw_scan_req->no_cck = req->no_cck;
272
273 return true;
274}
275
276static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted,
277 bool was_hw_scan)
278{
279 struct ieee80211_local *local = hw_to_local(hw);
280
281 lockdep_assert_held(&local->mtx);
282
283 /*
284 * It's ok to abort a not-yet-running scan (that
285 * we have one at all will be verified by checking
286 * local->scan_req next), but not to complete it
287 * successfully.
288 */
289 if (WARN_ON(!local->scanning && !aborted))
290 aborted = true;
291
292 if (WARN_ON(!local->scan_req))
293 return;
294
295 if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) {
296 int rc = drv_hw_scan(local, local->scan_sdata, local->hw_scan_req);
297 if (rc == 0)
298 return;
299 }
300
301 kfree(local->hw_scan_req);
302 local->hw_scan_req = NULL;
303
304 if (local->scan_req != local->int_scan_req)
305 cfg80211_scan_done(local->scan_req, aborted);
306 local->scan_req = NULL;
307 local->scan_sdata = NULL;
308
309 local->scanning = 0;
310 local->scan_channel = NULL;
311
312 /* Set power back to normal operating levels. */
313 ieee80211_hw_config(local, 0);
314
315 if (!was_hw_scan) {
316 ieee80211_configure_filter(local);
317 drv_sw_scan_complete(local);
318 ieee80211_offchannel_return(local, true);
319 }
320
321 ieee80211_recalc_idle(local);
322
323 ieee80211_mlme_notify_scan_completed(local);
324 ieee80211_ibss_notify_scan_completed(local);
325 ieee80211_mesh_notify_scan_completed(local);
326 ieee80211_queue_work(&local->hw, &local->work_work);
327}
328
329void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
330{
331 struct ieee80211_local *local = hw_to_local(hw);
332
333 trace_api_scan_completed(local, aborted);
334
335 set_bit(SCAN_COMPLETED, &local->scanning);
336 if (aborted)
337 set_bit(SCAN_ABORTED, &local->scanning);
338 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
339}
340EXPORT_SYMBOL(ieee80211_scan_completed);
341
342static int ieee80211_start_sw_scan(struct ieee80211_local *local)
343{
344 /*
345 * Hardware/driver doesn't support hw_scan, so use software
346 * scanning instead. First send a nullfunc frame with power save
347 * bit on so that AP will buffer the frames for us while we are not
348 * listening, then send probe requests to each channel and wait for
349 * the responses. After all channels are scanned, tune back to the
350 * original channel and send a nullfunc frame with power save bit
351 * off to trigger the AP to send us all the buffered frames.
352 *
353 * Note that while local->sw_scanning is true everything else but
354 * nullfunc frames and probe requests will be dropped in
355 * ieee80211_tx_h_check_assoc().
356 */
357 drv_sw_scan_start(local);
358
359 local->leave_oper_channel_time = jiffies;
360 local->next_scan_state = SCAN_DECISION;
361 local->scan_channel_idx = 0;
362
363 ieee80211_offchannel_stop_vifs(local, true);
364
365 ieee80211_configure_filter(local);
366
367 /* We need to set power level at maximum rate for scanning. */
368 ieee80211_hw_config(local, 0);
369
370 ieee80211_queue_delayed_work(&local->hw,
371 &local->scan_work, 0);
372
373 return 0;
374}
375
376static bool ieee80211_can_scan(struct ieee80211_local *local,
377 struct ieee80211_sub_if_data *sdata)
378{
379 if (!list_empty(&local->work_list))
380 return false;
381
382 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
383 sdata->u.mgd.flags & (IEEE80211_STA_BEACON_POLL |
384 IEEE80211_STA_CONNECTION_POLL))
385 return false;
386
387 return true;
388}
389
390void ieee80211_run_deferred_scan(struct ieee80211_local *local)
391{
392 lockdep_assert_held(&local->mtx);
393
394 if (!local->scan_req || local->scanning)
395 return;
396
397 if (!ieee80211_can_scan(local, local->scan_sdata))
398 return;
399
400 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
401 round_jiffies_relative(0));
402}
403
404static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
405 unsigned long *next_delay)
406{
407 int i;
408 struct ieee80211_sub_if_data *sdata = local->scan_sdata;
409 enum ieee80211_band band = local->hw.conf.channel->band;
410
411 for (i = 0; i < local->scan_req->n_ssids; i++)
412 ieee80211_send_probe_req(
413 sdata, NULL,
414 local->scan_req->ssids[i].ssid,
415 local->scan_req->ssids[i].ssid_len,
416 local->scan_req->ie, local->scan_req->ie_len,
417 local->scan_req->rates[band], false,
418 local->scan_req->no_cck);
419
420 /*
421 * After sending probe requests, wait for probe responses
422 * on the channel.
423 */
424 *next_delay = IEEE80211_CHANNEL_TIME;
425 local->next_scan_state = SCAN_DECISION;
426}
427
428static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
429 struct cfg80211_scan_request *req)
430{
431 struct ieee80211_local *local = sdata->local;
432 int rc;
433
434 lockdep_assert_held(&local->mtx);
435
436 if (local->scan_req)
437 return -EBUSY;
438
439 if (!ieee80211_can_scan(local, sdata)) {
440 /* wait for the work to finish/time out */
441 local->scan_req = req;
442 local->scan_sdata = sdata;
443 return 0;
444 }
445
446 if (local->ops->hw_scan) {
447 u8 *ies;
448
449 local->hw_scan_req = kmalloc(
450 sizeof(*local->hw_scan_req) +
451 req->n_channels * sizeof(req->channels[0]) +
452 2 + IEEE80211_MAX_SSID_LEN + local->scan_ies_len +
453 req->ie_len, GFP_KERNEL);
454 if (!local->hw_scan_req)
455 return -ENOMEM;
456
457 local->hw_scan_req->ssids = req->ssids;
458 local->hw_scan_req->n_ssids = req->n_ssids;
459 ies = (u8 *)local->hw_scan_req +
460 sizeof(*local->hw_scan_req) +
461 req->n_channels * sizeof(req->channels[0]);
462 local->hw_scan_req->ie = ies;
463
464 local->hw_scan_band = 0;
465
466 /*
467 * After allocating local->hw_scan_req, we must
468 * go through until ieee80211_prep_hw_scan(), so
469 * anything that might be changed here and leave
470 * this function early must not go after this
471 * allocation.
472 */
473 }
474
475 local->scan_req = req;
476 local->scan_sdata = sdata;
477
478 if (local->ops->hw_scan) {
479 __set_bit(SCAN_HW_SCANNING, &local->scanning);
480 } else if ((req->n_channels == 1) &&
481 (req->channels[0]->center_freq ==
482 local->hw.conf.channel->center_freq)) {
483
484 /* If we are scanning only on the current channel, then
485 * we do not need to stop normal activities
486 */
487 unsigned long next_delay;
488
489 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
490
491 ieee80211_recalc_idle(local);
492
493 /* Notify driver scan is starting, keep order of operations
494 * same as normal software scan, in case that matters. */
495 drv_sw_scan_start(local);
496
497 ieee80211_configure_filter(local); /* accept probe-responses */
498
499 /* We need to ensure power level is at max for scanning. */
500 ieee80211_hw_config(local, 0);
501
502 if ((req->channels[0]->flags &
503 IEEE80211_CHAN_PASSIVE_SCAN) ||
504 !local->scan_req->n_ssids) {
505 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
506 } else {
507 ieee80211_scan_state_send_probe(local, &next_delay);
508 next_delay = IEEE80211_CHANNEL_TIME;
509 }
510
511 /* Now, just wait a bit and we are all done! */
512 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
513 next_delay);
514 return 0;
515 } else {
516 /* Do normal software scan */
517 __set_bit(SCAN_SW_SCANNING, &local->scanning);
518 }
519
520 ieee80211_recalc_idle(local);
521
522 if (local->ops->hw_scan) {
523 WARN_ON(!ieee80211_prep_hw_scan(local));
524 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
525 } else
526 rc = ieee80211_start_sw_scan(local);
527
528 if (rc) {
529 kfree(local->hw_scan_req);
530 local->hw_scan_req = NULL;
531 local->scanning = 0;
532
533 ieee80211_recalc_idle(local);
534
535 local->scan_req = NULL;
536 local->scan_sdata = NULL;
537 }
538
539 return rc;
540}
541
542static unsigned long
543ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
544{
545 /*
546 * TODO: channel switching also consumes quite some time,
547 * add that delay as well to get a better estimation
548 */
549 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN)
550 return IEEE80211_PASSIVE_CHANNEL_TIME;
551 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
552}
553
554static void ieee80211_scan_state_decision(struct ieee80211_local *local,
555 unsigned long *next_delay)
556{
557 bool associated = false;
558 bool tx_empty = true;
559 bool bad_latency;
560 bool listen_int_exceeded;
561 unsigned long min_beacon_int = 0;
562 struct ieee80211_sub_if_data *sdata;
563 struct ieee80211_channel *next_chan;
564
565 /*
566 * check if at least one STA interface is associated,
567 * check if at least one STA interface has pending tx frames
568 * and grab the lowest used beacon interval
569 */
570 mutex_lock(&local->iflist_mtx);
571 list_for_each_entry(sdata, &local->interfaces, list) {
572 if (!ieee80211_sdata_running(sdata))
573 continue;
574
575 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
576 if (sdata->u.mgd.associated) {
577 associated = true;
578
579 if (sdata->vif.bss_conf.beacon_int <
580 min_beacon_int || min_beacon_int == 0)
581 min_beacon_int =
582 sdata->vif.bss_conf.beacon_int;
583
584 if (!qdisc_all_tx_empty(sdata->dev)) {
585 tx_empty = false;
586 break;
587 }
588 }
589 }
590 }
591 mutex_unlock(&local->iflist_mtx);
592
593 next_chan = local->scan_req->channels[local->scan_channel_idx];
594
595 /*
596 * we're currently scanning a different channel, let's
597 * see if we can scan another channel without interfering
598 * with the current traffic situation.
599 *
600 * Since we don't know if the AP has pending frames for us
601 * we can only check for our tx queues and use the current
602 * pm_qos requirements for rx. Hence, if no tx traffic occurs
603 * at all we will scan as many channels in a row as the pm_qos
604 * latency allows us to. Additionally we also check for the
605 * currently negotiated listen interval to prevent losing
606 * frames unnecessarily.
607 *
608 * Otherwise switch back to the operating channel.
609 */
610
611 bad_latency = time_after(jiffies +
612 ieee80211_scan_get_channel_time(next_chan),
613 local->leave_oper_channel_time +
614 usecs_to_jiffies(pm_qos_request(PM_QOS_NETWORK_LATENCY)));
615
616 listen_int_exceeded = time_after(jiffies +
617 ieee80211_scan_get_channel_time(next_chan),
618 local->leave_oper_channel_time +
619 usecs_to_jiffies(min_beacon_int * 1024) *
620 local->hw.conf.listen_interval);
621
622 if (associated && (!tx_empty || bad_latency || listen_int_exceeded))
623 local->next_scan_state = SCAN_SUSPEND;
624 else
625 local->next_scan_state = SCAN_SET_CHANNEL;
626
627 *next_delay = 0;
628}
629
630static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
631 unsigned long *next_delay)
632{
633 int skip;
634 struct ieee80211_channel *chan;
635
636 skip = 0;
637 chan = local->scan_req->channels[local->scan_channel_idx];
638
639 local->scan_channel = chan;
640
641 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
642 skip = 1;
643
644 /* advance state machine to next channel/band */
645 local->scan_channel_idx++;
646
647 if (skip) {
648 /* if we skip this channel return to the decision state */
649 local->next_scan_state = SCAN_DECISION;
650 return;
651 }
652
653 /*
654 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
655 * (which unfortunately doesn't say _why_ step a) is done,
656 * but it waits for the probe delay or until a frame is
657 * received - and the received frame would update the NAV).
658 * For now, we do not support waiting until a frame is
659 * received.
660 *
661 * In any case, it is not necessary for a passive scan.
662 */
663 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN ||
664 !local->scan_req->n_ssids) {
665 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
666 local->next_scan_state = SCAN_DECISION;
667 return;
668 }
669
670 /* active scan, send probes */
671 *next_delay = IEEE80211_PROBE_DELAY;
672 local->next_scan_state = SCAN_SEND_PROBE;
673}
674
675static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
676 unsigned long *next_delay)
677{
678 /* switch back to the operating channel */
679 local->scan_channel = NULL;
680 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
681
682 /*
683 * Re-enable vifs and beaconing. Leave PS
684 * in off-channel state..will put that back
685 * on-channel at the end of scanning.
686 */
687 ieee80211_offchannel_return(local, false);
688
689 *next_delay = HZ / 5;
690 /* afterwards, resume scan & go to next channel */
691 local->next_scan_state = SCAN_RESUME;
692}
693
694static void ieee80211_scan_state_resume(struct ieee80211_local *local,
695 unsigned long *next_delay)
696{
697 /* PS already is in off-channel mode */
698 ieee80211_offchannel_stop_vifs(local, false);
699
700 if (local->ops->flush) {
701 drv_flush(local, false);
702 *next_delay = 0;
703 } else
704 *next_delay = HZ / 10;
705
706 /* remember when we left the operating channel */
707 local->leave_oper_channel_time = jiffies;
708
709 /* advance to the next channel to be scanned */
710 local->next_scan_state = SCAN_SET_CHANNEL;
711}
712
713void ieee80211_scan_work(struct work_struct *work)
714{
715 struct ieee80211_local *local =
716 container_of(work, struct ieee80211_local, scan_work.work);
717 struct ieee80211_sub_if_data *sdata;
718 unsigned long next_delay = 0;
719 bool aborted, hw_scan;
720
721 mutex_lock(&local->mtx);
722
723 sdata = local->scan_sdata;
724
725 /* When scanning on-channel, the first-callback means completed. */
726 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
727 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
728 goto out_complete;
729 }
730
731 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
732 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
733 goto out_complete;
734 }
735
736 if (!sdata || !local->scan_req)
737 goto out;
738
739 if (local->scan_req && !local->scanning) {
740 struct cfg80211_scan_request *req = local->scan_req;
741 int rc;
742
743 local->scan_req = NULL;
744 local->scan_sdata = NULL;
745
746 rc = __ieee80211_start_scan(sdata, req);
747 if (rc) {
748 /* need to complete scan in cfg80211 */
749 local->scan_req = req;
750 aborted = true;
751 goto out_complete;
752 } else
753 goto out;
754 }
755
756 /*
757 * Avoid re-scheduling when the sdata is going away.
758 */
759 if (!ieee80211_sdata_running(sdata)) {
760 aborted = true;
761 goto out_complete;
762 }
763
764 /*
765 * as long as no delay is required advance immediately
766 * without scheduling a new work
767 */
768 do {
769 if (!ieee80211_sdata_running(sdata)) {
770 aborted = true;
771 goto out_complete;
772 }
773
774 switch (local->next_scan_state) {
775 case SCAN_DECISION:
776 /* if no more bands/channels left, complete scan */
777 if (local->scan_channel_idx >= local->scan_req->n_channels) {
778 aborted = false;
779 goto out_complete;
780 }
781 ieee80211_scan_state_decision(local, &next_delay);
782 break;
783 case SCAN_SET_CHANNEL:
784 ieee80211_scan_state_set_channel(local, &next_delay);
785 break;
786 case SCAN_SEND_PROBE:
787 ieee80211_scan_state_send_probe(local, &next_delay);
788 break;
789 case SCAN_SUSPEND:
790 ieee80211_scan_state_suspend(local, &next_delay);
791 break;
792 case SCAN_RESUME:
793 ieee80211_scan_state_resume(local, &next_delay);
794 break;
795 }
796 } while (next_delay == 0);
797
798 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
799 goto out;
800
801out_complete:
802 hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
803 __ieee80211_scan_completed(&local->hw, aborted, hw_scan);
804out:
805 mutex_unlock(&local->mtx);
806}
807
808int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
809 struct cfg80211_scan_request *req)
810{
811 int res;
812
813 mutex_lock(&sdata->local->mtx);
814 res = __ieee80211_start_scan(sdata, req);
815 mutex_unlock(&sdata->local->mtx);
816
817 return res;
818}
819
820int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata,
821 const u8 *ssid, u8 ssid_len,
822 struct ieee80211_channel *chan)
823{
824 struct ieee80211_local *local = sdata->local;
825 int ret = -EBUSY;
826 enum ieee80211_band band;
827
828 mutex_lock(&local->mtx);
829
830 /* busy scanning */
831 if (local->scan_req)
832 goto unlock;
833
834 /* fill internal scan request */
835 if (!chan) {
836 int i, nchan = 0;
837
838 for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
839 if (!local->hw.wiphy->bands[band])
840 continue;
841 for (i = 0;
842 i < local->hw.wiphy->bands[band]->n_channels;
843 i++) {
844 local->int_scan_req->channels[nchan] =
845 &local->hw.wiphy->bands[band]->channels[i];
846 nchan++;
847 }
848 }
849
850 local->int_scan_req->n_channels = nchan;
851 } else {
852 local->int_scan_req->channels[0] = chan;
853 local->int_scan_req->n_channels = 1;
854 }
855
856 local->int_scan_req->ssids = &local->scan_ssid;
857 local->int_scan_req->n_ssids = 1;
858 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
859 local->int_scan_req->ssids[0].ssid_len = ssid_len;
860
861 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
862 unlock:
863 mutex_unlock(&local->mtx);
864 return ret;
865}
866
867/*
868 * Only call this function when a scan can't be queued -- under RTNL.
869 */
870void ieee80211_scan_cancel(struct ieee80211_local *local)
871{
872 /*
873 * We are canceling software scan, or deferred scan that was not
874 * yet really started (see __ieee80211_start_scan ).
875 *
876 * Regarding hardware scan:
877 * - we can not call __ieee80211_scan_completed() as when
878 * SCAN_HW_SCANNING bit is set this function change
879 * local->hw_scan_req to operate on 5G band, what race with
880 * driver which can use local->hw_scan_req
881 *
882 * - we can not cancel scan_work since driver can schedule it
883 * by ieee80211_scan_completed(..., true) to finish scan
884 *
885 * Hence we only call the cancel_hw_scan() callback, but the low-level
886 * driver is still responsible for calling ieee80211_scan_completed()
887 * after the scan was completed/aborted.
888 */
889
890 mutex_lock(&local->mtx);
891 if (!local->scan_req)
892 goto out;
893
894 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
895 if (local->ops->cancel_hw_scan)
896 drv_cancel_hw_scan(local, local->scan_sdata);
897 goto out;
898 }
899
900 /*
901 * If the work is currently running, it must be blocked on
902 * the mutex, but we'll set scan_sdata = NULL and it'll
903 * simply exit once it acquires the mutex.
904 */
905 cancel_delayed_work(&local->scan_work);
906 /* and clean up */
907 __ieee80211_scan_completed(&local->hw, true, false);
908out:
909 mutex_unlock(&local->mtx);
910}
911
912int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
913 struct cfg80211_sched_scan_request *req)
914{
915 struct ieee80211_local *local = sdata->local;
916 int ret, i;
917
918 mutex_lock(&sdata->local->mtx);
919
920 if (local->sched_scanning) {
921 ret = -EBUSY;
922 goto out;
923 }
924
925 if (!local->ops->sched_scan_start) {
926 ret = -ENOTSUPP;
927 goto out;
928 }
929
930 for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
931 local->sched_scan_ies.ie[i] = kzalloc(2 +
932 IEEE80211_MAX_SSID_LEN +
933 local->scan_ies_len +
934 req->ie_len,
935 GFP_KERNEL);
936 if (!local->sched_scan_ies.ie[i]) {
937 ret = -ENOMEM;
938 goto out_free;
939 }
940
941 local->sched_scan_ies.len[i] =
942 ieee80211_build_preq_ies(local,
943 local->sched_scan_ies.ie[i],
944 req->ie, req->ie_len, i,
945 (u32) -1, 0);
946 }
947
948 ret = drv_sched_scan_start(local, sdata, req,
949 &local->sched_scan_ies);
950 if (ret == 0) {
951 local->sched_scanning = true;
952 goto out;
953 }
954
955out_free:
956 while (i > 0)
957 kfree(local->sched_scan_ies.ie[--i]);
958out:
959 mutex_unlock(&sdata->local->mtx);
960 return ret;
961}
962
963int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata)
964{
965 struct ieee80211_local *local = sdata->local;
966 int ret = 0, i;
967
968 mutex_lock(&sdata->local->mtx);
969
970 if (!local->ops->sched_scan_stop) {
971 ret = -ENOTSUPP;
972 goto out;
973 }
974
975 if (local->sched_scanning) {
976 for (i = 0; i < IEEE80211_NUM_BANDS; i++)
977 kfree(local->sched_scan_ies.ie[i]);
978
979 drv_sched_scan_stop(local, sdata);
980 local->sched_scanning = false;
981 }
982out:
983 mutex_unlock(&sdata->local->mtx);
984
985 return ret;
986}
987
988void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
989{
990 struct ieee80211_local *local = hw_to_local(hw);
991
992 trace_api_sched_scan_results(local);
993
994 cfg80211_sched_scan_results(hw->wiphy);
995}
996EXPORT_SYMBOL(ieee80211_sched_scan_results);
997
998void ieee80211_sched_scan_stopped_work(struct work_struct *work)
999{
1000 struct ieee80211_local *local =
1001 container_of(work, struct ieee80211_local,
1002 sched_scan_stopped_work);
1003 int i;
1004
1005 mutex_lock(&local->mtx);
1006
1007 if (!local->sched_scanning) {
1008 mutex_unlock(&local->mtx);
1009 return;
1010 }
1011
1012 for (i = 0; i < IEEE80211_NUM_BANDS; i++)
1013 kfree(local->sched_scan_ies.ie[i]);
1014
1015 local->sched_scanning = false;
1016
1017 mutex_unlock(&local->mtx);
1018
1019 cfg80211_sched_scan_stopped(local->hw.wiphy);
1020}
1021
1022void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1023{
1024 struct ieee80211_local *local = hw_to_local(hw);
1025
1026 trace_api_sched_scan_stopped(local);
1027
1028 ieee80211_queue_work(&local->hw, &local->sched_scan_stopped_work);
1029}
1030EXPORT_SYMBOL(ieee80211_sched_scan_stopped);