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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / net / mac80211 / scan.c
blobef2becaade5061ebddfabedba637c970db01042d
1 /*
2 * Scanning implementation
3 *
4 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
5 * Copyright 2004, Instant802 Networks, Inc.
6 * Copyright 2005, Devicescape Software, Inc.
7 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
8 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
9 * Copyright 2013-2015 Intel Mobile Communications GmbH
10 * Copyright 2016-2017 Intel Deutschland GmbH
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
15 */
16
17 #include <linux/if_arp.h>
18 #include <linux/etherdevice.h>
19 #include <linux/rtnetlink.h>
20 #include <net/sch_generic.h>
21 #include <linux/slab.h>
22 #include <linux/export.h>
23 #include <net/mac80211.h>
24
25 #include "ieee80211_i.h"
26 #include "driver-ops.h"
27 #include "mesh.h"
28
29 #define IEEE80211_PROBE_DELAY (HZ / 33)
30 #define IEEE80211_CHANNEL_TIME (HZ / 33)
31 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
32
33 void ieee80211_rx_bss_put(struct ieee80211_local *local,
34 struct ieee80211_bss *bss)
35 {
36 if (!bss)
37 return;
38 cfg80211_put_bss(local->hw.wiphy,
39 container_of((void *)bss, struct cfg80211_bss, priv));
40 }
41
42 static bool is_uapsd_supported(struct ieee802_11_elems *elems)
43 {
44 u8 qos_info;
45
46 if (elems->wmm_info && elems->wmm_info_len == 7
47 && elems->wmm_info[5] == 1)
48 qos_info = elems->wmm_info[6];
49 else if (elems->wmm_param && elems->wmm_param_len == 24
50 && elems->wmm_param[5] == 1)
51 qos_info = elems->wmm_param[6];
52 else
53 /* no valid wmm information or parameter element found */
54 return false;
55
56 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
57 }
58
59 struct ieee80211_bss *
60 ieee80211_bss_info_update(struct ieee80211_local *local,
61 struct ieee80211_rx_status *rx_status,
62 struct ieee80211_mgmt *mgmt, size_t len,
63 struct ieee802_11_elems *elems,
64 struct ieee80211_channel *channel)
65 {
66 bool beacon = ieee80211_is_beacon(mgmt->frame_control);
67 struct cfg80211_bss *cbss;
68 struct ieee80211_bss *bss;
69 int clen, srlen;
70 struct cfg80211_inform_bss bss_meta = {
71 .boottime_ns = rx_status->boottime_ns,
72 };
73 bool signal_valid;
74 struct ieee80211_sub_if_data *scan_sdata;
75
76 if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
77 bss_meta.signal = rx_status->signal * 100;
78 else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
79 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
80
81 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
82 if (rx_status->bw == RATE_INFO_BW_5)
83 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
84 else if (rx_status->bw == RATE_INFO_BW_10)
85 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
86
87 bss_meta.chan = channel;
88
89 rcu_read_lock();
90 scan_sdata = rcu_dereference(local->scan_sdata);
91 if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
92 scan_sdata->vif.bss_conf.assoc &&
93 ieee80211_have_rx_timestamp(rx_status)) {
94 bss_meta.parent_tsf =
95 ieee80211_calculate_rx_timestamp(local, rx_status,
96 len + FCS_LEN, 24);
97 ether_addr_copy(bss_meta.parent_bssid,
98 scan_sdata->vif.bss_conf.bssid);
99 }
100 rcu_read_unlock();
101
102 cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
103 mgmt, len, GFP_ATOMIC);
104 if (!cbss)
105 return NULL;
106 /* In case the signal is invalid update the status */
107 signal_valid = abs(channel->center_freq - cbss->channel->center_freq)
108 <= local->hw.wiphy->max_adj_channel_rssi_comp;
109 if (!signal_valid)
110 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
111
112 bss = (void *)cbss->priv;
113
114 if (beacon)
115 bss->device_ts_beacon = rx_status->device_timestamp;
116 else
117 bss->device_ts_presp = rx_status->device_timestamp;
118
119 if (elems->parse_error) {
120 if (beacon)
121 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
122 else
123 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
124 } else {
125 if (beacon)
126 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
127 else
128 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
129 }
130
131 /* save the ERP value so that it is available at association time */
132 if (elems->erp_info && (!elems->parse_error ||
133 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
134 bss->erp_value = elems->erp_info[0];
135 bss->has_erp_value = true;
136 if (!elems->parse_error)
137 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
138 }
139
140 /* replace old supported rates if we get new values */
141 if (!elems->parse_error ||
142 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
143 srlen = 0;
144 if (elems->supp_rates) {
145 clen = IEEE80211_MAX_SUPP_RATES;
146 if (clen > elems->supp_rates_len)
147 clen = elems->supp_rates_len;
148 memcpy(bss->supp_rates, elems->supp_rates, clen);
149 srlen += clen;
150 }
151 if (elems->ext_supp_rates) {
152 clen = IEEE80211_MAX_SUPP_RATES - srlen;
153 if (clen > elems->ext_supp_rates_len)
154 clen = elems->ext_supp_rates_len;
155 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
156 clen);
157 srlen += clen;
158 }
159 if (srlen) {
160 bss->supp_rates_len = srlen;
161 if (!elems->parse_error)
162 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
163 }
164 }
165
166 if (!elems->parse_error ||
167 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
168 bss->wmm_used = elems->wmm_param || elems->wmm_info;
169 bss->uapsd_supported = is_uapsd_supported(elems);
170 if (!elems->parse_error)
171 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
172 }
173
174 if (beacon) {
175 struct ieee80211_supported_band *sband =
176 local->hw.wiphy->bands[rx_status->band];
177 if (!(rx_status->encoding == RX_ENC_HT) &&
178 !(rx_status->encoding == RX_ENC_VHT))
179 bss->beacon_rate =
180 &sband->bitrates[rx_status->rate_idx];
181 }
182
183 return bss;
184 }
185
186 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
187 u32 scan_flags, const u8 *da)
188 {
189 if (!sdata)
190 return false;
191 /* accept broadcast for OCE */
192 if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
193 is_broadcast_ether_addr(da))
194 return true;
195 if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
196 return true;
197 return ether_addr_equal(da, sdata->vif.addr);
198 }
199
200 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
201 {
202 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
203 struct ieee80211_sub_if_data *sdata1, *sdata2;
204 struct ieee80211_mgmt *mgmt = (void *)skb->data;
205 struct ieee80211_bss *bss;
206 u8 *elements;
207 struct ieee80211_channel *channel;
208 size_t baselen;
209 struct ieee802_11_elems elems;
210
211 if (skb->len < 24 ||
212 (!ieee80211_is_probe_resp(mgmt->frame_control) &&
213 !ieee80211_is_beacon(mgmt->frame_control)))
214 return;
215
216 sdata1 = rcu_dereference(local->scan_sdata);
217 sdata2 = rcu_dereference(local->sched_scan_sdata);
218
219 if (likely(!sdata1 && !sdata2))
220 return;
221
222 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
223 struct cfg80211_scan_request *scan_req;
224 struct cfg80211_sched_scan_request *sched_scan_req;
225 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
226
227 scan_req = rcu_dereference(local->scan_req);
228 sched_scan_req = rcu_dereference(local->sched_scan_req);
229
230 if (scan_req)
231 scan_req_flags = scan_req->flags;
232
233 if (sched_scan_req)
234 sched_scan_req_flags = sched_scan_req->flags;
235
236 /* ignore ProbeResp to foreign address or non-bcast (OCE)
237 * unless scanning with randomised address
238 */
239 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
240 mgmt->da) &&
241 !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
242 mgmt->da))
243 return;
244
245 elements = mgmt->u.probe_resp.variable;
246 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
247 } else {
248 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
249 elements = mgmt->u.beacon.variable;
250 }
251
252 if (baselen > skb->len)
253 return;
254
255 ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems);
256
257 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
258
259 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
260 return;
261
262 bss = ieee80211_bss_info_update(local, rx_status,
263 mgmt, skb->len, &elems,
264 channel);
265 if (bss)
266 ieee80211_rx_bss_put(local, bss);
267 }
268
269 static void
270 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
271 enum nl80211_bss_scan_width scan_width)
272 {
273 memset(chandef, 0, sizeof(*chandef));
274 switch (scan_width) {
275 case NL80211_BSS_CHAN_WIDTH_5:
276 chandef->width = NL80211_CHAN_WIDTH_5;
277 break;
278 case NL80211_BSS_CHAN_WIDTH_10:
279 chandef->width = NL80211_CHAN_WIDTH_10;
280 break;
281 default:
282 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
283 break;
284 }
285 }
286
287 /* return false if no more work */
288 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
289 {
290 struct cfg80211_scan_request *req;
291 struct cfg80211_chan_def chandef;
292 u8 bands_used = 0;
293 int i, ielen, n_chans;
294
295 req = rcu_dereference_protected(local->scan_req,
296 lockdep_is_held(&local->mtx));
297
298 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
299 return false;
300
301 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
302 for (i = 0; i < req->n_channels; i++) {
303 local->hw_scan_req->req.channels[i] = req->channels[i];
304 bands_used |= BIT(req->channels[i]->band);
305 }
306
307 n_chans = req->n_channels;
308 } else {
309 do {
310 if (local->hw_scan_band == NUM_NL80211_BANDS)
311 return false;
312
313 n_chans = 0;
314
315 for (i = 0; i < req->n_channels; i++) {
316 if (req->channels[i]->band !=
317 local->hw_scan_band)
318 continue;
319 local->hw_scan_req->req.channels[n_chans] =
320 req->channels[i];
321 n_chans++;
322 bands_used |= BIT(req->channels[i]->band);
323 }
324
325 local->hw_scan_band++;
326 } while (!n_chans);
327 }
328
329 local->hw_scan_req->req.n_channels = n_chans;
330 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
331
332 ielen = ieee80211_build_preq_ies(local,
333 (u8 *)local->hw_scan_req->req.ie,
334 local->hw_scan_ies_bufsize,
335 &local->hw_scan_req->ies,
336 req->ie, req->ie_len,
337 bands_used, req->rates, &chandef);
338 local->hw_scan_req->req.ie_len = ielen;
339 local->hw_scan_req->req.no_cck = req->no_cck;
340 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
341 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
342 req->mac_addr_mask);
343 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
344
345 return true;
346 }
347
348 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
349 {
350 struct ieee80211_local *local = hw_to_local(hw);
351 bool hw_scan = local->ops->hw_scan;
352 bool was_scanning = local->scanning;
353 struct cfg80211_scan_request *scan_req;
354 struct ieee80211_sub_if_data *scan_sdata;
355 struct ieee80211_sub_if_data *sdata;
356
357 lockdep_assert_held(&local->mtx);
358
359 /*
360 * It's ok to abort a not-yet-running scan (that
361 * we have one at all will be verified by checking
362 * local->scan_req next), but not to complete it
363 * successfully.
364 */
365 if (WARN_ON(!local->scanning && !aborted))
366 aborted = true;
367
368 if (WARN_ON(!local->scan_req))
369 return;
370
371 if (hw_scan && !aborted &&
372 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
373 ieee80211_prep_hw_scan(local)) {
374 int rc;
375
376 rc = drv_hw_scan(local,
377 rcu_dereference_protected(local->scan_sdata,
378 lockdep_is_held(&local->mtx)),
379 local->hw_scan_req);
380
381 if (rc == 0)
382 return;
383
384 /* HW scan failed and is going to be reported as aborted,
385 * so clear old scan info.
386 */
387 memset(&local->scan_info, 0, sizeof(local->scan_info));
388 aborted = true;
389 }
390
391 kfree(local->hw_scan_req);
392 local->hw_scan_req = NULL;
393
394 scan_req = rcu_dereference_protected(local->scan_req,
395 lockdep_is_held(&local->mtx));
396
397 if (scan_req != local->int_scan_req) {
398 local->scan_info.aborted = aborted;
399 cfg80211_scan_done(scan_req, &local->scan_info);
400 }
401 RCU_INIT_POINTER(local->scan_req, NULL);
402
403 scan_sdata = rcu_dereference_protected(local->scan_sdata,
404 lockdep_is_held(&local->mtx));
405 RCU_INIT_POINTER(local->scan_sdata, NULL);
406
407 local->scanning = 0;
408 local->scan_chandef.chan = NULL;
409
410 /* Set power back to normal operating levels. */
411 ieee80211_hw_config(local, 0);
412
413 if (!hw_scan) {
414 ieee80211_configure_filter(local);
415 drv_sw_scan_complete(local, scan_sdata);
416 ieee80211_offchannel_return(local);
417 }
418
419 ieee80211_recalc_idle(local);
420
421 ieee80211_mlme_notify_scan_completed(local);
422 ieee80211_ibss_notify_scan_completed(local);
423
424 /* Requeue all the work that might have been ignored while
425 * the scan was in progress; if there was none this will
426 * just be a no-op for the particular interface.
427 */
428 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
429 if (ieee80211_sdata_running(sdata))
430 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
431 }
432
433 if (was_scanning)
434 ieee80211_start_next_roc(local);
435 }
436
437 void ieee80211_scan_completed(struct ieee80211_hw *hw,
438 struct cfg80211_scan_info *info)
439 {
440 struct ieee80211_local *local = hw_to_local(hw);
441
442 trace_api_scan_completed(local, info->aborted);
443
444 set_bit(SCAN_COMPLETED, &local->scanning);
445 if (info->aborted)
446 set_bit(SCAN_ABORTED, &local->scanning);
447
448 memcpy(&local->scan_info, info, sizeof(*info));
449
450 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
451 }
452 EXPORT_SYMBOL(ieee80211_scan_completed);
453
454 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
455 struct ieee80211_sub_if_data *sdata)
456 {
457 /* Software scan is not supported in multi-channel cases */
458 if (local->use_chanctx)
459 return -EOPNOTSUPP;
460
461 /*
462 * Hardware/driver doesn't support hw_scan, so use software
463 * scanning instead. First send a nullfunc frame with power save
464 * bit on so that AP will buffer the frames for us while we are not
465 * listening, then send probe requests to each channel and wait for
466 * the responses. After all channels are scanned, tune back to the
467 * original channel and send a nullfunc frame with power save bit
468 * off to trigger the AP to send us all the buffered frames.
469 *
470 * Note that while local->sw_scanning is true everything else but
471 * nullfunc frames and probe requests will be dropped in
472 * ieee80211_tx_h_check_assoc().
473 */
474 drv_sw_scan_start(local, sdata, local->scan_addr);
475
476 local->leave_oper_channel_time = jiffies;
477 local->next_scan_state = SCAN_DECISION;
478 local->scan_channel_idx = 0;
479
480 ieee80211_offchannel_stop_vifs(local);
481
482 /* ensure nullfunc is transmitted before leaving operating channel */
483 ieee80211_flush_queues(local, NULL, false);
484
485 ieee80211_configure_filter(local);
486
487 /* We need to set power level at maximum rate for scanning. */
488 ieee80211_hw_config(local, 0);
489
490 ieee80211_queue_delayed_work(&local->hw,
491 &local->scan_work, 0);
492
493 return 0;
494 }
495
496 static bool ieee80211_can_scan(struct ieee80211_local *local,
497 struct ieee80211_sub_if_data *sdata)
498 {
499 if (ieee80211_is_radar_required(local))
500 return false;
501
502 if (!list_empty(&local->roc_list))
503 return false;
504
505 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
506 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
507 return false;
508
509 return true;
510 }
511
512 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
513 {
514 lockdep_assert_held(&local->mtx);
515
516 if (!local->scan_req || local->scanning)
517 return;
518
519 if (!ieee80211_can_scan(local,
520 rcu_dereference_protected(
521 local->scan_sdata,
522 lockdep_is_held(&local->mtx))))
523 return;
524
525 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
526 round_jiffies_relative(0));
527 }
528
529 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
530 unsigned long *next_delay)
531 {
532 int i;
533 struct ieee80211_sub_if_data *sdata;
534 struct cfg80211_scan_request *scan_req;
535 enum nl80211_band band = local->hw.conf.chandef.chan->band;
536 u32 tx_flags;
537
538 scan_req = rcu_dereference_protected(local->scan_req,
539 lockdep_is_held(&local->mtx));
540
541 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
542 if (scan_req->no_cck)
543 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
544
545 sdata = rcu_dereference_protected(local->scan_sdata,
546 lockdep_is_held(&local->mtx));
547
548 for (i = 0; i < scan_req->n_ssids; i++)
549 ieee80211_send_probe_req(
550 sdata, local->scan_addr, scan_req->bssid,
551 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
552 scan_req->ie, scan_req->ie_len,
553 scan_req->rates[band], false,
554 tx_flags, local->hw.conf.chandef.chan, true);
555
556 /*
557 * After sending probe requests, wait for probe responses
558 * on the channel.
559 */
560 *next_delay = IEEE80211_CHANNEL_TIME;
561 local->next_scan_state = SCAN_DECISION;
562 }
563
564 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
565 struct cfg80211_scan_request *req)
566 {
567 struct ieee80211_local *local = sdata->local;
568 int rc;
569
570 lockdep_assert_held(&local->mtx);
571
572 if (local->scan_req || ieee80211_is_radar_required(local))
573 return -EBUSY;
574
575 if (!ieee80211_can_scan(local, sdata)) {
576 /* wait for the work to finish/time out */
577 rcu_assign_pointer(local->scan_req, req);
578 rcu_assign_pointer(local->scan_sdata, sdata);
579 return 0;
580 }
581
582 if (local->ops->hw_scan) {
583 u8 *ies;
584
585 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
586
587 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
588 int i, n_bands = 0;
589 u8 bands_counted = 0;
590
591 for (i = 0; i < req->n_channels; i++) {
592 if (bands_counted & BIT(req->channels[i]->band))
593 continue;
594 bands_counted |= BIT(req->channels[i]->band);
595 n_bands++;
596 }
597
598 local->hw_scan_ies_bufsize *= n_bands;
599 }
600
601 local->hw_scan_req = kmalloc(
602 sizeof(*local->hw_scan_req) +
603 req->n_channels * sizeof(req->channels[0]) +
604 local->hw_scan_ies_bufsize, GFP_KERNEL);
605 if (!local->hw_scan_req)
606 return -ENOMEM;
607
608 local->hw_scan_req->req.ssids = req->ssids;
609 local->hw_scan_req->req.n_ssids = req->n_ssids;
610 ies = (u8 *)local->hw_scan_req +
611 sizeof(*local->hw_scan_req) +
612 req->n_channels * sizeof(req->channels[0]);
613 local->hw_scan_req->req.ie = ies;
614 local->hw_scan_req->req.flags = req->flags;
615 eth_broadcast_addr(local->hw_scan_req->req.bssid);
616 local->hw_scan_req->req.duration = req->duration;
617 local->hw_scan_req->req.duration_mandatory =
618 req->duration_mandatory;
619
620 local->hw_scan_band = 0;
621
622 /*
623 * After allocating local->hw_scan_req, we must
624 * go through until ieee80211_prep_hw_scan(), so
625 * anything that might be changed here and leave
626 * this function early must not go after this
627 * allocation.
628 */
629 }
630
631 rcu_assign_pointer(local->scan_req, req);
632 rcu_assign_pointer(local->scan_sdata, sdata);
633
634 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
635 get_random_mask_addr(local->scan_addr,
636 req->mac_addr,
637 req->mac_addr_mask);
638 else
639 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
640
641 if (local->ops->hw_scan) {
642 __set_bit(SCAN_HW_SCANNING, &local->scanning);
643 } else if ((req->n_channels == 1) &&
644 (req->channels[0] == local->_oper_chandef.chan)) {
645 /*
646 * If we are scanning only on the operating channel
647 * then we do not need to stop normal activities
648 */
649 unsigned long next_delay;
650
651 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
652
653 ieee80211_recalc_idle(local);
654
655 /* Notify driver scan is starting, keep order of operations
656 * same as normal software scan, in case that matters. */
657 drv_sw_scan_start(local, sdata, local->scan_addr);
658
659 ieee80211_configure_filter(local); /* accept probe-responses */
660
661 /* We need to ensure power level is at max for scanning. */
662 ieee80211_hw_config(local, 0);
663
664 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
665 IEEE80211_CHAN_RADAR)) ||
666 !req->n_ssids) {
667 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
668 } else {
669 ieee80211_scan_state_send_probe(local, &next_delay);
670 next_delay = IEEE80211_CHANNEL_TIME;
671 }
672
673 /* Now, just wait a bit and we are all done! */
674 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
675 next_delay);
676 return 0;
677 } else {
678 /* Do normal software scan */
679 __set_bit(SCAN_SW_SCANNING, &local->scanning);
680 }
681
682 ieee80211_recalc_idle(local);
683
684 if (local->ops->hw_scan) {
685 WARN_ON(!ieee80211_prep_hw_scan(local));
686 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
687 } else {
688 rc = ieee80211_start_sw_scan(local, sdata);
689 }
690
691 if (rc) {
692 kfree(local->hw_scan_req);
693 local->hw_scan_req = NULL;
694 local->scanning = 0;
695
696 ieee80211_recalc_idle(local);
697
698 local->scan_req = NULL;
699 RCU_INIT_POINTER(local->scan_sdata, NULL);
700 }
701
702 return rc;
703 }
704
705 static unsigned long
706 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
707 {
708 /*
709 * TODO: channel switching also consumes quite some time,
710 * add that delay as well to get a better estimation
711 */
712 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
713 return IEEE80211_PASSIVE_CHANNEL_TIME;
714 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
715 }
716
717 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
718 unsigned long *next_delay)
719 {
720 bool associated = false;
721 bool tx_empty = true;
722 bool bad_latency;
723 struct ieee80211_sub_if_data *sdata;
724 struct ieee80211_channel *next_chan;
725 enum mac80211_scan_state next_scan_state;
726 struct cfg80211_scan_request *scan_req;
727
728 /*
729 * check if at least one STA interface is associated,
730 * check if at least one STA interface has pending tx frames
731 * and grab the lowest used beacon interval
732 */
733 mutex_lock(&local->iflist_mtx);
734 list_for_each_entry(sdata, &local->interfaces, list) {
735 if (!ieee80211_sdata_running(sdata))
736 continue;
737
738 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
739 if (sdata->u.mgd.associated) {
740 associated = true;
741
742 if (!qdisc_all_tx_empty(sdata->dev)) {
743 tx_empty = false;
744 break;
745 }
746 }
747 }
748 }
749 mutex_unlock(&local->iflist_mtx);
750
751 scan_req = rcu_dereference_protected(local->scan_req,
752 lockdep_is_held(&local->mtx));
753
754 next_chan = scan_req->channels[local->scan_channel_idx];
755
756 /*
757 * we're currently scanning a different channel, let's
758 * see if we can scan another channel without interfering
759 * with the current traffic situation.
760 *
761 * Keep good latency, do not stay off-channel more than 125 ms.
762 */
763
764 bad_latency = time_after(jiffies +
765 ieee80211_scan_get_channel_time(next_chan),
766 local->leave_oper_channel_time + HZ / 8);
767
768 if (associated && !tx_empty) {
769 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
770 next_scan_state = SCAN_ABORT;
771 else
772 next_scan_state = SCAN_SUSPEND;
773 } else if (associated && bad_latency) {
774 next_scan_state = SCAN_SUSPEND;
775 } else {
776 next_scan_state = SCAN_SET_CHANNEL;
777 }
778
779 local->next_scan_state = next_scan_state;
780
781 *next_delay = 0;
782 }
783
784 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
785 unsigned long *next_delay)
786 {
787 int skip;
788 struct ieee80211_channel *chan;
789 enum nl80211_bss_scan_width oper_scan_width;
790 struct cfg80211_scan_request *scan_req;
791
792 scan_req = rcu_dereference_protected(local->scan_req,
793 lockdep_is_held(&local->mtx));
794
795 skip = 0;
796 chan = scan_req->channels[local->scan_channel_idx];
797
798 local->scan_chandef.chan = chan;
799 local->scan_chandef.center_freq1 = chan->center_freq;
800 local->scan_chandef.center_freq2 = 0;
801 switch (scan_req->scan_width) {
802 case NL80211_BSS_CHAN_WIDTH_5:
803 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
804 break;
805 case NL80211_BSS_CHAN_WIDTH_10:
806 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
807 break;
808 case NL80211_BSS_CHAN_WIDTH_20:
809 /* If scanning on oper channel, use whatever channel-type
810 * is currently in use.
811 */
812 oper_scan_width = cfg80211_chandef_to_scan_width(
813 &local->_oper_chandef);
814 if (chan == local->_oper_chandef.chan &&
815 oper_scan_width == scan_req->scan_width)
816 local->scan_chandef = local->_oper_chandef;
817 else
818 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
819 break;
820 }
821
822 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
823 skip = 1;
824
825 /* advance state machine to next channel/band */
826 local->scan_channel_idx++;
827
828 if (skip) {
829 /* if we skip this channel return to the decision state */
830 local->next_scan_state = SCAN_DECISION;
831 return;
832 }
833
834 /*
835 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
836 * (which unfortunately doesn't say _why_ step a) is done,
837 * but it waits for the probe delay or until a frame is
838 * received - and the received frame would update the NAV).
839 * For now, we do not support waiting until a frame is
840 * received.
841 *
842 * In any case, it is not necessary for a passive scan.
843 */
844 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
845 !scan_req->n_ssids) {
846 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
847 local->next_scan_state = SCAN_DECISION;
848 return;
849 }
850
851 /* active scan, send probes */
852 *next_delay = IEEE80211_PROBE_DELAY;
853 local->next_scan_state = SCAN_SEND_PROBE;
854 }
855
856 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
857 unsigned long *next_delay)
858 {
859 /* switch back to the operating channel */
860 local->scan_chandef.chan = NULL;
861 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
862
863 /* disable PS */
864 ieee80211_offchannel_return(local);
865
866 *next_delay = HZ / 5;
867 /* afterwards, resume scan & go to next channel */
868 local->next_scan_state = SCAN_RESUME;
869 }
870
871 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
872 unsigned long *next_delay)
873 {
874 ieee80211_offchannel_stop_vifs(local);
875
876 if (local->ops->flush) {
877 ieee80211_flush_queues(local, NULL, false);
878 *next_delay = 0;
879 } else
880 *next_delay = HZ / 10;
881
882 /* remember when we left the operating channel */
883 local->leave_oper_channel_time = jiffies;
884
885 /* advance to the next channel to be scanned */
886 local->next_scan_state = SCAN_SET_CHANNEL;
887 }
888
889 void ieee80211_scan_work(struct work_struct *work)
890 {
891 struct ieee80211_local *local =
892 container_of(work, struct ieee80211_local, scan_work.work);
893 struct ieee80211_sub_if_data *sdata;
894 struct cfg80211_scan_request *scan_req;
895 unsigned long next_delay = 0;
896 bool aborted;
897
898 mutex_lock(&local->mtx);
899
900 if (!ieee80211_can_run_worker(local)) {
901 aborted = true;
902 goto out_complete;
903 }
904
905 sdata = rcu_dereference_protected(local->scan_sdata,
906 lockdep_is_held(&local->mtx));
907 scan_req = rcu_dereference_protected(local->scan_req,
908 lockdep_is_held(&local->mtx));
909
910 /* When scanning on-channel, the first-callback means completed. */
911 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
912 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
913 goto out_complete;
914 }
915
916 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
917 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
918 goto out_complete;
919 }
920
921 if (!sdata || !scan_req)
922 goto out;
923
924 if (!local->scanning) {
925 int rc;
926
927 RCU_INIT_POINTER(local->scan_req, NULL);
928 RCU_INIT_POINTER(local->scan_sdata, NULL);
929
930 rc = __ieee80211_start_scan(sdata, scan_req);
931 if (rc) {
932 /* need to complete scan in cfg80211 */
933 rcu_assign_pointer(local->scan_req, scan_req);
934 aborted = true;
935 goto out_complete;
936 } else
937 goto out;
938 }
939
940 /*
941 * as long as no delay is required advance immediately
942 * without scheduling a new work
943 */
944 do {
945 if (!ieee80211_sdata_running(sdata)) {
946 aborted = true;
947 goto out_complete;
948 }
949
950 switch (local->next_scan_state) {
951 case SCAN_DECISION:
952 /* if no more bands/channels left, complete scan */
953 if (local->scan_channel_idx >= scan_req->n_channels) {
954 aborted = false;
955 goto out_complete;
956 }
957 ieee80211_scan_state_decision(local, &next_delay);
958 break;
959 case SCAN_SET_CHANNEL:
960 ieee80211_scan_state_set_channel(local, &next_delay);
961 break;
962 case SCAN_SEND_PROBE:
963 ieee80211_scan_state_send_probe(local, &next_delay);
964 break;
965 case SCAN_SUSPEND:
966 ieee80211_scan_state_suspend(local, &next_delay);
967 break;
968 case SCAN_RESUME:
969 ieee80211_scan_state_resume(local, &next_delay);
970 break;
971 case SCAN_ABORT:
972 aborted = true;
973 goto out_complete;
974 }
975 } while (next_delay == 0);
976
977 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
978 goto out;
979
980 out_complete:
981 __ieee80211_scan_completed(&local->hw, aborted);
982 out:
983 mutex_unlock(&local->mtx);
984 }
985
986 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
987 struct cfg80211_scan_request *req)
988 {
989 int res;
990
991 mutex_lock(&sdata->local->mtx);
992 res = __ieee80211_start_scan(sdata, req);
993 mutex_unlock(&sdata->local->mtx);
994
995 return res;
996 }
997
998 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
999 const u8 *ssid, u8 ssid_len,
1000 struct ieee80211_channel **channels,
1001 unsigned int n_channels,
1002 enum nl80211_bss_scan_width scan_width)
1003 {
1004 struct ieee80211_local *local = sdata->local;
1005 int ret = -EBUSY, i, n_ch = 0;
1006 enum nl80211_band band;
1007
1008 mutex_lock(&local->mtx);
1009
1010 /* busy scanning */
1011 if (local->scan_req)
1012 goto unlock;
1013
1014 /* fill internal scan request */
1015 if (!channels) {
1016 int max_n;
1017
1018 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1019 if (!local->hw.wiphy->bands[band])
1020 continue;
1021
1022 max_n = local->hw.wiphy->bands[band]->n_channels;
1023 for (i = 0; i < max_n; i++) {
1024 struct ieee80211_channel *tmp_ch =
1025 &local->hw.wiphy->bands[band]->channels[i];
1026
1027 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1028 IEEE80211_CHAN_DISABLED))
1029 continue;
1030
1031 local->int_scan_req->channels[n_ch] = tmp_ch;
1032 n_ch++;
1033 }
1034 }
1035
1036 if (WARN_ON_ONCE(n_ch == 0))
1037 goto unlock;
1038
1039 local->int_scan_req->n_channels = n_ch;
1040 } else {
1041 for (i = 0; i < n_channels; i++) {
1042 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1043 IEEE80211_CHAN_DISABLED))
1044 continue;
1045
1046 local->int_scan_req->channels[n_ch] = channels[i];
1047 n_ch++;
1048 }
1049
1050 if (WARN_ON_ONCE(n_ch == 0))
1051 goto unlock;
1052
1053 local->int_scan_req->n_channels = n_ch;
1054 }
1055
1056 local->int_scan_req->ssids = &local->scan_ssid;
1057 local->int_scan_req->n_ssids = 1;
1058 local->int_scan_req->scan_width = scan_width;
1059 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1060 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1061
1062 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1063 unlock:
1064 mutex_unlock(&local->mtx);
1065 return ret;
1066 }
1067
1068 /*
1069 * Only call this function when a scan can't be queued -- under RTNL.
1070 */
1071 void ieee80211_scan_cancel(struct ieee80211_local *local)
1072 {
1073 /*
1074 * We are canceling software scan, or deferred scan that was not
1075 * yet really started (see __ieee80211_start_scan ).
1076 *
1077 * Regarding hardware scan:
1078 * - we can not call __ieee80211_scan_completed() as when
1079 * SCAN_HW_SCANNING bit is set this function change
1080 * local->hw_scan_req to operate on 5G band, what race with
1081 * driver which can use local->hw_scan_req
1082 *
1083 * - we can not cancel scan_work since driver can schedule it
1084 * by ieee80211_scan_completed(..., true) to finish scan
1085 *
1086 * Hence we only call the cancel_hw_scan() callback, but the low-level
1087 * driver is still responsible for calling ieee80211_scan_completed()
1088 * after the scan was completed/aborted.
1089 */
1090
1091 mutex_lock(&local->mtx);
1092 if (!local->scan_req)
1093 goto out;
1094
1095 /*
1096 * We have a scan running and the driver already reported completion,
1097 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1098 * cancelled.
1099 */
1100 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1101 test_bit(SCAN_COMPLETED, &local->scanning)) {
1102 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1103 goto out;
1104 }
1105
1106 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1107 /*
1108 * Make sure that __ieee80211_scan_completed doesn't trigger a
1109 * scan on another band.
1110 */
1111 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1112 if (local->ops->cancel_hw_scan)
1113 drv_cancel_hw_scan(local,
1114 rcu_dereference_protected(local->scan_sdata,
1115 lockdep_is_held(&local->mtx)));
1116 goto out;
1117 }
1118
1119 /*
1120 * If the work is currently running, it must be blocked on
1121 * the mutex, but we'll set scan_sdata = NULL and it'll
1122 * simply exit once it acquires the mutex.
1123 */
1124 cancel_delayed_work(&local->scan_work);
1125 /* and clean up */
1126 memset(&local->scan_info, 0, sizeof(local->scan_info));
1127 __ieee80211_scan_completed(&local->hw, true);
1128 out:
1129 mutex_unlock(&local->mtx);
1130 }
1131
1132 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1133 struct cfg80211_sched_scan_request *req)
1134 {
1135 struct ieee80211_local *local = sdata->local;
1136 struct ieee80211_scan_ies sched_scan_ies = {};
1137 struct cfg80211_chan_def chandef;
1138 int ret, i, iebufsz, num_bands = 0;
1139 u32 rate_masks[NUM_NL80211_BANDS] = {};
1140 u8 bands_used = 0;
1141 u8 *ie;
1142
1143 iebufsz = local->scan_ies_len + req->ie_len;
1144
1145 lockdep_assert_held(&local->mtx);
1146
1147 if (!local->ops->sched_scan_start)
1148 return -ENOTSUPP;
1149
1150 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1151 if (local->hw.wiphy->bands[i]) {
1152 bands_used |= BIT(i);
1153 rate_masks[i] = (u32) -1;
1154 num_bands++;
1155 }
1156 }
1157
1158 ie = kzalloc(num_bands * iebufsz, GFP_KERNEL);
1159 if (!ie) {
1160 ret = -ENOMEM;
1161 goto out;
1162 }
1163
1164 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1165
1166 ieee80211_build_preq_ies(local, ie, num_bands * iebufsz,
1167 &sched_scan_ies, req->ie,
1168 req->ie_len, bands_used, rate_masks, &chandef);
1169
1170 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1171 if (ret == 0) {
1172 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1173 rcu_assign_pointer(local->sched_scan_req, req);
1174 }
1175
1176 kfree(ie);
1177
1178 out:
1179 if (ret) {
1180 /* Clean in case of failure after HW restart or upon resume. */
1181 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1182 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1183 }
1184
1185 return ret;
1186 }
1187
1188 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1189 struct cfg80211_sched_scan_request *req)
1190 {
1191 struct ieee80211_local *local = sdata->local;
1192 int ret;
1193
1194 mutex_lock(&local->mtx);
1195
1196 if (rcu_access_pointer(local->sched_scan_sdata)) {
1197 mutex_unlock(&local->mtx);
1198 return -EBUSY;
1199 }
1200
1201 ret = __ieee80211_request_sched_scan_start(sdata, req);
1202
1203 mutex_unlock(&local->mtx);
1204 return ret;
1205 }
1206
1207 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1208 {
1209 struct ieee80211_sub_if_data *sched_scan_sdata;
1210 int ret = -ENOENT;
1211
1212 mutex_lock(&local->mtx);
1213
1214 if (!local->ops->sched_scan_stop) {
1215 ret = -ENOTSUPP;
1216 goto out;
1217 }
1218
1219 /* We don't want to restart sched scan anymore. */
1220 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1221
1222 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1223 lockdep_is_held(&local->mtx));
1224 if (sched_scan_sdata) {
1225 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1226 if (!ret)
1227 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1228 }
1229 out:
1230 mutex_unlock(&local->mtx);
1231
1232 return ret;
1233 }
1234
1235 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1236 {
1237 struct ieee80211_local *local = hw_to_local(hw);
1238
1239 trace_api_sched_scan_results(local);
1240
1241 cfg80211_sched_scan_results(hw->wiphy, 0);
1242 }
1243 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1244
1245 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1246 {
1247 mutex_lock(&local->mtx);
1248
1249 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1250 mutex_unlock(&local->mtx);
1251 return;
1252 }
1253
1254 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1255
1256 /* If sched scan was aborted by the driver. */
1257 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1258
1259 mutex_unlock(&local->mtx);
1260
1261 cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1262 }
1263
1264 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1265 {
1266 struct ieee80211_local *local =
1267 container_of(work, struct ieee80211_local,
1268 sched_scan_stopped_work);
1269
1270 ieee80211_sched_scan_end(local);
1271 }
1272
1273 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1274 {
1275 struct ieee80211_local *local = hw_to_local(hw);
1276
1277 trace_api_sched_scan_stopped(local);
1278
1279 /*
1280 * this shouldn't really happen, so for simplicity
1281 * simply ignore it, and let mac80211 reconfigure
1282 * the sched scan later on.
1283 */
1284 if (local->in_reconfig)
1285 return;
1286
1287 schedule_work(&local->sched_scan_stopped_work);
1288 }
1289 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
CRIS linux kernel tree