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mac80211: mesh: flush mesh paths unconditionally
[deliverable/linux.git] / net / mac80211 / scan.c
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 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 */
15
16 #include <linux/if_arp.h>
17 #include <linux/etherdevice.h>
18 #include <linux/rtnetlink.h>
19 #include <net/sch_generic.h>
20 #include <linux/slab.h>
21 #include <linux/export.h>
22 #include <net/mac80211.h>
23
24 #include "ieee80211_i.h"
25 #include "driver-ops.h"
26 #include "mesh.h"
27
28 #define IEEE80211_PROBE_DELAY (HZ / 33)
29 #define IEEE80211_CHANNEL_TIME (HZ / 33)
30 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
31
32 void 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
41 static 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
58 struct ieee80211_bss *
59 ieee80211_bss_info_update(struct ieee80211_local *local,
60 struct ieee80211_rx_status *rx_status,
61 struct ieee80211_mgmt *mgmt, size_t len,
62 struct ieee802_11_elems *elems,
63 struct ieee80211_channel *channel)
64 {
65 bool beacon = ieee80211_is_beacon(mgmt->frame_control);
66 struct cfg80211_bss *cbss;
67 struct ieee80211_bss *bss;
68 int clen, srlen;
69 struct cfg80211_inform_bss bss_meta = {
70 .boottime_ns = rx_status->boottime_ns,
71 };
72 bool signal_valid;
73
74 if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
75 bss_meta.signal = rx_status->signal * 100;
76 else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
77 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
78
79 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
80 if (rx_status->flag & RX_FLAG_5MHZ)
81 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
82 if (rx_status->flag & RX_FLAG_10MHZ)
83 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
84
85 bss_meta.chan = channel;
86 cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
87 mgmt, len, GFP_ATOMIC);
88 if (!cbss)
89 return NULL;
90 /* In case the signal is invalid update the status */
91 signal_valid = abs(channel->center_freq - cbss->channel->center_freq)
92 <= local->hw.wiphy->max_adj_channel_rssi_comp;
93 if (!signal_valid)
94 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
95
96 bss = (void *)cbss->priv;
97
98 if (beacon)
99 bss->device_ts_beacon = rx_status->device_timestamp;
100 else
101 bss->device_ts_presp = rx_status->device_timestamp;
102
103 if (elems->parse_error) {
104 if (beacon)
105 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
106 else
107 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
108 } else {
109 if (beacon)
110 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
111 else
112 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
113 }
114
115 /* save the ERP value so that it is available at association time */
116 if (elems->erp_info && (!elems->parse_error ||
117 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
118 bss->erp_value = elems->erp_info[0];
119 bss->has_erp_value = true;
120 if (!elems->parse_error)
121 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
122 }
123
124 /* replace old supported rates if we get new values */
125 if (!elems->parse_error ||
126 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
127 srlen = 0;
128 if (elems->supp_rates) {
129 clen = IEEE80211_MAX_SUPP_RATES;
130 if (clen > elems->supp_rates_len)
131 clen = elems->supp_rates_len;
132 memcpy(bss->supp_rates, elems->supp_rates, clen);
133 srlen += clen;
134 }
135 if (elems->ext_supp_rates) {
136 clen = IEEE80211_MAX_SUPP_RATES - srlen;
137 if (clen > elems->ext_supp_rates_len)
138 clen = elems->ext_supp_rates_len;
139 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
140 clen);
141 srlen += clen;
142 }
143 if (srlen) {
144 bss->supp_rates_len = srlen;
145 if (!elems->parse_error)
146 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
147 }
148 }
149
150 if (!elems->parse_error ||
151 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
152 bss->wmm_used = elems->wmm_param || elems->wmm_info;
153 bss->uapsd_supported = is_uapsd_supported(elems);
154 if (!elems->parse_error)
155 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
156 }
157
158 if (beacon) {
159 struct ieee80211_supported_band *sband =
160 local->hw.wiphy->bands[rx_status->band];
161 if (!(rx_status->flag & RX_FLAG_HT) &&
162 !(rx_status->flag & RX_FLAG_VHT))
163 bss->beacon_rate =
164 &sband->bitrates[rx_status->rate_idx];
165 }
166
167 return bss;
168 }
169
170 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
171 {
172 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
173 struct ieee80211_sub_if_data *sdata1, *sdata2;
174 struct ieee80211_mgmt *mgmt = (void *)skb->data;
175 struct ieee80211_bss *bss;
176 u8 *elements;
177 struct ieee80211_channel *channel;
178 size_t baselen;
179 struct ieee802_11_elems elems;
180
181 if (skb->len < 24 ||
182 (!ieee80211_is_probe_resp(mgmt->frame_control) &&
183 !ieee80211_is_beacon(mgmt->frame_control)))
184 return;
185
186 sdata1 = rcu_dereference(local->scan_sdata);
187 sdata2 = rcu_dereference(local->sched_scan_sdata);
188
189 if (likely(!sdata1 && !sdata2))
190 return;
191
192 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
193 struct cfg80211_scan_request *scan_req;
194 struct cfg80211_sched_scan_request *sched_scan_req;
195
196 scan_req = rcu_dereference(local->scan_req);
197 sched_scan_req = rcu_dereference(local->sched_scan_req);
198
199 /* ignore ProbeResp to foreign address unless scanning
200 * with randomised address
201 */
202 if (!(sdata1 &&
203 (ether_addr_equal(mgmt->da, sdata1->vif.addr) ||
204 scan_req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)) &&
205 !(sdata2 &&
206 (ether_addr_equal(mgmt->da, sdata2->vif.addr) ||
207 sched_scan_req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)))
208 return;
209
210 elements = mgmt->u.probe_resp.variable;
211 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
212 } else {
213 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
214 elements = mgmt->u.beacon.variable;
215 }
216
217 if (baselen > skb->len)
218 return;
219
220 ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems);
221
222 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
223
224 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
225 return;
226
227 bss = ieee80211_bss_info_update(local, rx_status,
228 mgmt, skb->len, &elems,
229 channel);
230 if (bss)
231 ieee80211_rx_bss_put(local, bss);
232 }
233
234 static void
235 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
236 enum nl80211_bss_scan_width scan_width)
237 {
238 memset(chandef, 0, sizeof(*chandef));
239 switch (scan_width) {
240 case NL80211_BSS_CHAN_WIDTH_5:
241 chandef->width = NL80211_CHAN_WIDTH_5;
242 break;
243 case NL80211_BSS_CHAN_WIDTH_10:
244 chandef->width = NL80211_CHAN_WIDTH_10;
245 break;
246 default:
247 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
248 break;
249 }
250 }
251
252 /* return false if no more work */
253 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
254 {
255 struct cfg80211_scan_request *req;
256 struct cfg80211_chan_def chandef;
257 u8 bands_used = 0;
258 int i, ielen, n_chans;
259
260 req = rcu_dereference_protected(local->scan_req,
261 lockdep_is_held(&local->mtx));
262
263 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
264 return false;
265
266 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
267 for (i = 0; i < req->n_channels; i++) {
268 local->hw_scan_req->req.channels[i] = req->channels[i];
269 bands_used |= BIT(req->channels[i]->band);
270 }
271
272 n_chans = req->n_channels;
273 } else {
274 do {
275 if (local->hw_scan_band == NUM_NL80211_BANDS)
276 return false;
277
278 n_chans = 0;
279
280 for (i = 0; i < req->n_channels; i++) {
281 if (req->channels[i]->band !=
282 local->hw_scan_band)
283 continue;
284 local->hw_scan_req->req.channels[n_chans] =
285 req->channels[i];
286 n_chans++;
287 bands_used |= BIT(req->channels[i]->band);
288 }
289
290 local->hw_scan_band++;
291 } while (!n_chans);
292 }
293
294 local->hw_scan_req->req.n_channels = n_chans;
295 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
296
297 ielen = ieee80211_build_preq_ies(local,
298 (u8 *)local->hw_scan_req->req.ie,
299 local->hw_scan_ies_bufsize,
300 &local->hw_scan_req->ies,
301 req->ie, req->ie_len,
302 bands_used, req->rates, &chandef);
303 local->hw_scan_req->req.ie_len = ielen;
304 local->hw_scan_req->req.no_cck = req->no_cck;
305 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
306 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
307 req->mac_addr_mask);
308 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
309
310 return true;
311 }
312
313 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
314 {
315 struct ieee80211_local *local = hw_to_local(hw);
316 bool hw_scan = local->ops->hw_scan;
317 bool was_scanning = local->scanning;
318 struct cfg80211_scan_request *scan_req;
319 struct ieee80211_sub_if_data *scan_sdata;
320 struct ieee80211_sub_if_data *sdata;
321
322 lockdep_assert_held(&local->mtx);
323
324 /*
325 * It's ok to abort a not-yet-running scan (that
326 * we have one at all will be verified by checking
327 * local->scan_req next), but not to complete it
328 * successfully.
329 */
330 if (WARN_ON(!local->scanning && !aborted))
331 aborted = true;
332
333 if (WARN_ON(!local->scan_req))
334 return;
335
336 if (hw_scan && !aborted &&
337 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
338 ieee80211_prep_hw_scan(local)) {
339 int rc;
340
341 rc = drv_hw_scan(local,
342 rcu_dereference_protected(local->scan_sdata,
343 lockdep_is_held(&local->mtx)),
344 local->hw_scan_req);
345
346 if (rc == 0)
347 return;
348 }
349
350 kfree(local->hw_scan_req);
351 local->hw_scan_req = NULL;
352
353 scan_req = rcu_dereference_protected(local->scan_req,
354 lockdep_is_held(&local->mtx));
355
356 if (scan_req != local->int_scan_req)
357 cfg80211_scan_done(scan_req, aborted);
358 RCU_INIT_POINTER(local->scan_req, NULL);
359
360 scan_sdata = rcu_dereference_protected(local->scan_sdata,
361 lockdep_is_held(&local->mtx));
362 RCU_INIT_POINTER(local->scan_sdata, NULL);
363
364 local->scanning = 0;
365 local->scan_chandef.chan = NULL;
366
367 /* Set power back to normal operating levels. */
368 ieee80211_hw_config(local, 0);
369
370 if (!hw_scan) {
371 ieee80211_configure_filter(local);
372 drv_sw_scan_complete(local, scan_sdata);
373 ieee80211_offchannel_return(local);
374 }
375
376 ieee80211_recalc_idle(local);
377
378 ieee80211_mlme_notify_scan_completed(local);
379 ieee80211_ibss_notify_scan_completed(local);
380
381 /* Requeue all the work that might have been ignored while
382 * the scan was in progress; if there was none this will
383 * just be a no-op for the particular interface.
384 */
385 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
386 if (ieee80211_sdata_running(sdata))
387 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
388 }
389
390 if (was_scanning)
391 ieee80211_start_next_roc(local);
392 }
393
394 void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
395 {
396 struct ieee80211_local *local = hw_to_local(hw);
397
398 trace_api_scan_completed(local, aborted);
399
400 set_bit(SCAN_COMPLETED, &local->scanning);
401 if (aborted)
402 set_bit(SCAN_ABORTED, &local->scanning);
403 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
404 }
405 EXPORT_SYMBOL(ieee80211_scan_completed);
406
407 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
408 struct ieee80211_sub_if_data *sdata)
409 {
410 /* Software scan is not supported in multi-channel cases */
411 if (local->use_chanctx)
412 return -EOPNOTSUPP;
413
414 /*
415 * Hardware/driver doesn't support hw_scan, so use software
416 * scanning instead. First send a nullfunc frame with power save
417 * bit on so that AP will buffer the frames for us while we are not
418 * listening, then send probe requests to each channel and wait for
419 * the responses. After all channels are scanned, tune back to the
420 * original channel and send a nullfunc frame with power save bit
421 * off to trigger the AP to send us all the buffered frames.
422 *
423 * Note that while local->sw_scanning is true everything else but
424 * nullfunc frames and probe requests will be dropped in
425 * ieee80211_tx_h_check_assoc().
426 */
427 drv_sw_scan_start(local, sdata, local->scan_addr);
428
429 local->leave_oper_channel_time = jiffies;
430 local->next_scan_state = SCAN_DECISION;
431 local->scan_channel_idx = 0;
432
433 ieee80211_offchannel_stop_vifs(local);
434
435 /* ensure nullfunc is transmitted before leaving operating channel */
436 ieee80211_flush_queues(local, NULL, false);
437
438 ieee80211_configure_filter(local);
439
440 /* We need to set power level at maximum rate for scanning. */
441 ieee80211_hw_config(local, 0);
442
443 ieee80211_queue_delayed_work(&local->hw,
444 &local->scan_work, 0);
445
446 return 0;
447 }
448
449 static bool ieee80211_can_scan(struct ieee80211_local *local,
450 struct ieee80211_sub_if_data *sdata)
451 {
452 if (ieee80211_is_radar_required(local))
453 return false;
454
455 if (!list_empty(&local->roc_list))
456 return false;
457
458 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
459 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
460 return false;
461
462 return true;
463 }
464
465 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
466 {
467 lockdep_assert_held(&local->mtx);
468
469 if (!local->scan_req || local->scanning)
470 return;
471
472 if (!ieee80211_can_scan(local,
473 rcu_dereference_protected(
474 local->scan_sdata,
475 lockdep_is_held(&local->mtx))))
476 return;
477
478 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
479 round_jiffies_relative(0));
480 }
481
482 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
483 unsigned long *next_delay)
484 {
485 int i;
486 struct ieee80211_sub_if_data *sdata;
487 struct cfg80211_scan_request *scan_req;
488 enum nl80211_band band = local->hw.conf.chandef.chan->band;
489 u32 tx_flags;
490
491 scan_req = rcu_dereference_protected(local->scan_req,
492 lockdep_is_held(&local->mtx));
493
494 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
495 if (scan_req->no_cck)
496 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
497
498 sdata = rcu_dereference_protected(local->scan_sdata,
499 lockdep_is_held(&local->mtx));
500
501 for (i = 0; i < scan_req->n_ssids; i++)
502 ieee80211_send_probe_req(
503 sdata, local->scan_addr, scan_req->bssid,
504 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
505 scan_req->ie, scan_req->ie_len,
506 scan_req->rates[band], false,
507 tx_flags, local->hw.conf.chandef.chan, true);
508
509 /*
510 * After sending probe requests, wait for probe responses
511 * on the channel.
512 */
513 *next_delay = IEEE80211_CHANNEL_TIME;
514 local->next_scan_state = SCAN_DECISION;
515 }
516
517 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
518 struct cfg80211_scan_request *req)
519 {
520 struct ieee80211_local *local = sdata->local;
521 int rc;
522
523 lockdep_assert_held(&local->mtx);
524
525 if (local->scan_req || ieee80211_is_radar_required(local))
526 return -EBUSY;
527
528 if (!ieee80211_can_scan(local, sdata)) {
529 /* wait for the work to finish/time out */
530 rcu_assign_pointer(local->scan_req, req);
531 rcu_assign_pointer(local->scan_sdata, sdata);
532 return 0;
533 }
534
535 if (local->ops->hw_scan) {
536 u8 *ies;
537
538 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
539
540 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
541 int i, n_bands = 0;
542 u8 bands_counted = 0;
543
544 for (i = 0; i < req->n_channels; i++) {
545 if (bands_counted & BIT(req->channels[i]->band))
546 continue;
547 bands_counted |= BIT(req->channels[i]->band);
548 n_bands++;
549 }
550
551 local->hw_scan_ies_bufsize *= n_bands;
552 }
553
554 local->hw_scan_req = kmalloc(
555 sizeof(*local->hw_scan_req) +
556 req->n_channels * sizeof(req->channels[0]) +
557 local->hw_scan_ies_bufsize, GFP_KERNEL);
558 if (!local->hw_scan_req)
559 return -ENOMEM;
560
561 local->hw_scan_req->req.ssids = req->ssids;
562 local->hw_scan_req->req.n_ssids = req->n_ssids;
563 ies = (u8 *)local->hw_scan_req +
564 sizeof(*local->hw_scan_req) +
565 req->n_channels * sizeof(req->channels[0]);
566 local->hw_scan_req->req.ie = ies;
567 local->hw_scan_req->req.flags = req->flags;
568 eth_broadcast_addr(local->hw_scan_req->req.bssid);
569
570 local->hw_scan_band = 0;
571
572 /*
573 * After allocating local->hw_scan_req, we must
574 * go through until ieee80211_prep_hw_scan(), so
575 * anything that might be changed here and leave
576 * this function early must not go after this
577 * allocation.
578 */
579 }
580
581 rcu_assign_pointer(local->scan_req, req);
582 rcu_assign_pointer(local->scan_sdata, sdata);
583
584 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
585 get_random_mask_addr(local->scan_addr,
586 req->mac_addr,
587 req->mac_addr_mask);
588 else
589 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
590
591 if (local->ops->hw_scan) {
592 __set_bit(SCAN_HW_SCANNING, &local->scanning);
593 } else if ((req->n_channels == 1) &&
594 (req->channels[0] == local->_oper_chandef.chan)) {
595 /*
596 * If we are scanning only on the operating channel
597 * then we do not need to stop normal activities
598 */
599 unsigned long next_delay;
600
601 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
602
603 ieee80211_recalc_idle(local);
604
605 /* Notify driver scan is starting, keep order of operations
606 * same as normal software scan, in case that matters. */
607 drv_sw_scan_start(local, sdata, local->scan_addr);
608
609 ieee80211_configure_filter(local); /* accept probe-responses */
610
611 /* We need to ensure power level is at max for scanning. */
612 ieee80211_hw_config(local, 0);
613
614 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
615 IEEE80211_CHAN_RADAR)) ||
616 !req->n_ssids) {
617 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
618 } else {
619 ieee80211_scan_state_send_probe(local, &next_delay);
620 next_delay = IEEE80211_CHANNEL_TIME;
621 }
622
623 /* Now, just wait a bit and we are all done! */
624 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
625 next_delay);
626 return 0;
627 } else {
628 /* Do normal software scan */
629 __set_bit(SCAN_SW_SCANNING, &local->scanning);
630 }
631
632 ieee80211_recalc_idle(local);
633
634 if (local->ops->hw_scan) {
635 WARN_ON(!ieee80211_prep_hw_scan(local));
636 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
637 } else {
638 rc = ieee80211_start_sw_scan(local, sdata);
639 }
640
641 if (rc) {
642 kfree(local->hw_scan_req);
643 local->hw_scan_req = NULL;
644 local->scanning = 0;
645
646 ieee80211_recalc_idle(local);
647
648 local->scan_req = NULL;
649 RCU_INIT_POINTER(local->scan_sdata, NULL);
650 }
651
652 return rc;
653 }
654
655 static unsigned long
656 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
657 {
658 /*
659 * TODO: channel switching also consumes quite some time,
660 * add that delay as well to get a better estimation
661 */
662 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
663 return IEEE80211_PASSIVE_CHANNEL_TIME;
664 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
665 }
666
667 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
668 unsigned long *next_delay)
669 {
670 bool associated = false;
671 bool tx_empty = true;
672 bool bad_latency;
673 struct ieee80211_sub_if_data *sdata;
674 struct ieee80211_channel *next_chan;
675 enum mac80211_scan_state next_scan_state;
676 struct cfg80211_scan_request *scan_req;
677
678 /*
679 * check if at least one STA interface is associated,
680 * check if at least one STA interface has pending tx frames
681 * and grab the lowest used beacon interval
682 */
683 mutex_lock(&local->iflist_mtx);
684 list_for_each_entry(sdata, &local->interfaces, list) {
685 if (!ieee80211_sdata_running(sdata))
686 continue;
687
688 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
689 if (sdata->u.mgd.associated) {
690 associated = true;
691
692 if (!qdisc_all_tx_empty(sdata->dev)) {
693 tx_empty = false;
694 break;
695 }
696 }
697 }
698 }
699 mutex_unlock(&local->iflist_mtx);
700
701 scan_req = rcu_dereference_protected(local->scan_req,
702 lockdep_is_held(&local->mtx));
703
704 next_chan = scan_req->channels[local->scan_channel_idx];
705
706 /*
707 * we're currently scanning a different channel, let's
708 * see if we can scan another channel without interfering
709 * with the current traffic situation.
710 *
711 * Keep good latency, do not stay off-channel more than 125 ms.
712 */
713
714 bad_latency = time_after(jiffies +
715 ieee80211_scan_get_channel_time(next_chan),
716 local->leave_oper_channel_time + HZ / 8);
717
718 if (associated && !tx_empty) {
719 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
720 next_scan_state = SCAN_ABORT;
721 else
722 next_scan_state = SCAN_SUSPEND;
723 } else if (associated && bad_latency) {
724 next_scan_state = SCAN_SUSPEND;
725 } else {
726 next_scan_state = SCAN_SET_CHANNEL;
727 }
728
729 local->next_scan_state = next_scan_state;
730
731 *next_delay = 0;
732 }
733
734 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
735 unsigned long *next_delay)
736 {
737 int skip;
738 struct ieee80211_channel *chan;
739 enum nl80211_bss_scan_width oper_scan_width;
740 struct cfg80211_scan_request *scan_req;
741
742 scan_req = rcu_dereference_protected(local->scan_req,
743 lockdep_is_held(&local->mtx));
744
745 skip = 0;
746 chan = scan_req->channels[local->scan_channel_idx];
747
748 local->scan_chandef.chan = chan;
749 local->scan_chandef.center_freq1 = chan->center_freq;
750 local->scan_chandef.center_freq2 = 0;
751 switch (scan_req->scan_width) {
752 case NL80211_BSS_CHAN_WIDTH_5:
753 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
754 break;
755 case NL80211_BSS_CHAN_WIDTH_10:
756 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
757 break;
758 case NL80211_BSS_CHAN_WIDTH_20:
759 /* If scanning on oper channel, use whatever channel-type
760 * is currently in use.
761 */
762 oper_scan_width = cfg80211_chandef_to_scan_width(
763 &local->_oper_chandef);
764 if (chan == local->_oper_chandef.chan &&
765 oper_scan_width == scan_req->scan_width)
766 local->scan_chandef = local->_oper_chandef;
767 else
768 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
769 break;
770 }
771
772 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
773 skip = 1;
774
775 /* advance state machine to next channel/band */
776 local->scan_channel_idx++;
777
778 if (skip) {
779 /* if we skip this channel return to the decision state */
780 local->next_scan_state = SCAN_DECISION;
781 return;
782 }
783
784 /*
785 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
786 * (which unfortunately doesn't say _why_ step a) is done,
787 * but it waits for the probe delay or until a frame is
788 * received - and the received frame would update the NAV).
789 * For now, we do not support waiting until a frame is
790 * received.
791 *
792 * In any case, it is not necessary for a passive scan.
793 */
794 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
795 !scan_req->n_ssids) {
796 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
797 local->next_scan_state = SCAN_DECISION;
798 return;
799 }
800
801 /* active scan, send probes */
802 *next_delay = IEEE80211_PROBE_DELAY;
803 local->next_scan_state = SCAN_SEND_PROBE;
804 }
805
806 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
807 unsigned long *next_delay)
808 {
809 /* switch back to the operating channel */
810 local->scan_chandef.chan = NULL;
811 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
812
813 /* disable PS */
814 ieee80211_offchannel_return(local);
815
816 *next_delay = HZ / 5;
817 /* afterwards, resume scan & go to next channel */
818 local->next_scan_state = SCAN_RESUME;
819 }
820
821 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
822 unsigned long *next_delay)
823 {
824 ieee80211_offchannel_stop_vifs(local);
825
826 if (local->ops->flush) {
827 ieee80211_flush_queues(local, NULL, false);
828 *next_delay = 0;
829 } else
830 *next_delay = HZ / 10;
831
832 /* remember when we left the operating channel */
833 local->leave_oper_channel_time = jiffies;
834
835 /* advance to the next channel to be scanned */
836 local->next_scan_state = SCAN_SET_CHANNEL;
837 }
838
839 void ieee80211_scan_work(struct work_struct *work)
840 {
841 struct ieee80211_local *local =
842 container_of(work, struct ieee80211_local, scan_work.work);
843 struct ieee80211_sub_if_data *sdata;
844 struct cfg80211_scan_request *scan_req;
845 unsigned long next_delay = 0;
846 bool aborted;
847
848 mutex_lock(&local->mtx);
849
850 if (!ieee80211_can_run_worker(local)) {
851 aborted = true;
852 goto out_complete;
853 }
854
855 sdata = rcu_dereference_protected(local->scan_sdata,
856 lockdep_is_held(&local->mtx));
857 scan_req = rcu_dereference_protected(local->scan_req,
858 lockdep_is_held(&local->mtx));
859
860 /* When scanning on-channel, the first-callback means completed. */
861 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
862 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
863 goto out_complete;
864 }
865
866 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
867 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
868 goto out_complete;
869 }
870
871 if (!sdata || !scan_req)
872 goto out;
873
874 if (!local->scanning) {
875 int rc;
876
877 RCU_INIT_POINTER(local->scan_req, NULL);
878 RCU_INIT_POINTER(local->scan_sdata, NULL);
879
880 rc = __ieee80211_start_scan(sdata, scan_req);
881 if (rc) {
882 /* need to complete scan in cfg80211 */
883 rcu_assign_pointer(local->scan_req, scan_req);
884 aborted = true;
885 goto out_complete;
886 } else
887 goto out;
888 }
889
890 /*
891 * as long as no delay is required advance immediately
892 * without scheduling a new work
893 */
894 do {
895 if (!ieee80211_sdata_running(sdata)) {
896 aborted = true;
897 goto out_complete;
898 }
899
900 switch (local->next_scan_state) {
901 case SCAN_DECISION:
902 /* if no more bands/channels left, complete scan */
903 if (local->scan_channel_idx >= scan_req->n_channels) {
904 aborted = false;
905 goto out_complete;
906 }
907 ieee80211_scan_state_decision(local, &next_delay);
908 break;
909 case SCAN_SET_CHANNEL:
910 ieee80211_scan_state_set_channel(local, &next_delay);
911 break;
912 case SCAN_SEND_PROBE:
913 ieee80211_scan_state_send_probe(local, &next_delay);
914 break;
915 case SCAN_SUSPEND:
916 ieee80211_scan_state_suspend(local, &next_delay);
917 break;
918 case SCAN_RESUME:
919 ieee80211_scan_state_resume(local, &next_delay);
920 break;
921 case SCAN_ABORT:
922 aborted = true;
923 goto out_complete;
924 }
925 } while (next_delay == 0);
926
927 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
928 goto out;
929
930 out_complete:
931 __ieee80211_scan_completed(&local->hw, aborted);
932 out:
933 mutex_unlock(&local->mtx);
934 }
935
936 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
937 struct cfg80211_scan_request *req)
938 {
939 int res;
940
941 mutex_lock(&sdata->local->mtx);
942 res = __ieee80211_start_scan(sdata, req);
943 mutex_unlock(&sdata->local->mtx);
944
945 return res;
946 }
947
948 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
949 const u8 *ssid, u8 ssid_len,
950 struct ieee80211_channel **channels,
951 unsigned int n_channels,
952 enum nl80211_bss_scan_width scan_width)
953 {
954 struct ieee80211_local *local = sdata->local;
955 int ret = -EBUSY, i, n_ch = 0;
956 enum nl80211_band band;
957
958 mutex_lock(&local->mtx);
959
960 /* busy scanning */
961 if (local->scan_req)
962 goto unlock;
963
964 /* fill internal scan request */
965 if (!channels) {
966 int max_n;
967
968 for (band = 0; band < NUM_NL80211_BANDS; band++) {
969 if (!local->hw.wiphy->bands[band])
970 continue;
971
972 max_n = local->hw.wiphy->bands[band]->n_channels;
973 for (i = 0; i < max_n; i++) {
974 struct ieee80211_channel *tmp_ch =
975 &local->hw.wiphy->bands[band]->channels[i];
976
977 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
978 IEEE80211_CHAN_DISABLED))
979 continue;
980
981 local->int_scan_req->channels[n_ch] = tmp_ch;
982 n_ch++;
983 }
984 }
985
986 if (WARN_ON_ONCE(n_ch == 0))
987 goto unlock;
988
989 local->int_scan_req->n_channels = n_ch;
990 } else {
991 for (i = 0; i < n_channels; i++) {
992 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
993 IEEE80211_CHAN_DISABLED))
994 continue;
995
996 local->int_scan_req->channels[n_ch] = channels[i];
997 n_ch++;
998 }
999
1000 if (WARN_ON_ONCE(n_ch == 0))
1001 goto unlock;
1002
1003 local->int_scan_req->n_channels = n_ch;
1004 }
1005
1006 local->int_scan_req->ssids = &local->scan_ssid;
1007 local->int_scan_req->n_ssids = 1;
1008 local->int_scan_req->scan_width = scan_width;
1009 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1010 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1011
1012 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1013 unlock:
1014 mutex_unlock(&local->mtx);
1015 return ret;
1016 }
1017
1018 /*
1019 * Only call this function when a scan can't be queued -- under RTNL.
1020 */
1021 void ieee80211_scan_cancel(struct ieee80211_local *local)
1022 {
1023 /*
1024 * We are canceling software scan, or deferred scan that was not
1025 * yet really started (see __ieee80211_start_scan ).
1026 *
1027 * Regarding hardware scan:
1028 * - we can not call __ieee80211_scan_completed() as when
1029 * SCAN_HW_SCANNING bit is set this function change
1030 * local->hw_scan_req to operate on 5G band, what race with
1031 * driver which can use local->hw_scan_req
1032 *
1033 * - we can not cancel scan_work since driver can schedule it
1034 * by ieee80211_scan_completed(..., true) to finish scan
1035 *
1036 * Hence we only call the cancel_hw_scan() callback, but the low-level
1037 * driver is still responsible for calling ieee80211_scan_completed()
1038 * after the scan was completed/aborted.
1039 */
1040
1041 mutex_lock(&local->mtx);
1042 if (!local->scan_req)
1043 goto out;
1044
1045 /*
1046 * We have a scan running and the driver already reported completion,
1047 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1048 * cancelled.
1049 */
1050 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1051 test_bit(SCAN_COMPLETED, &local->scanning)) {
1052 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1053 goto out;
1054 }
1055
1056 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1057 /*
1058 * Make sure that __ieee80211_scan_completed doesn't trigger a
1059 * scan on another band.
1060 */
1061 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1062 if (local->ops->cancel_hw_scan)
1063 drv_cancel_hw_scan(local,
1064 rcu_dereference_protected(local->scan_sdata,
1065 lockdep_is_held(&local->mtx)));
1066 goto out;
1067 }
1068
1069 /*
1070 * If the work is currently running, it must be blocked on
1071 * the mutex, but we'll set scan_sdata = NULL and it'll
1072 * simply exit once it acquires the mutex.
1073 */
1074 cancel_delayed_work(&local->scan_work);
1075 /* and clean up */
1076 __ieee80211_scan_completed(&local->hw, true);
1077 out:
1078 mutex_unlock(&local->mtx);
1079 }
1080
1081 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1082 struct cfg80211_sched_scan_request *req)
1083 {
1084 struct ieee80211_local *local = sdata->local;
1085 struct ieee80211_scan_ies sched_scan_ies = {};
1086 struct cfg80211_chan_def chandef;
1087 int ret, i, iebufsz, num_bands = 0;
1088 u32 rate_masks[NUM_NL80211_BANDS] = {};
1089 u8 bands_used = 0;
1090 u8 *ie;
1091 size_t len;
1092
1093 iebufsz = local->scan_ies_len + req->ie_len;
1094
1095 lockdep_assert_held(&local->mtx);
1096
1097 if (!local->ops->sched_scan_start)
1098 return -ENOTSUPP;
1099
1100 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1101 if (local->hw.wiphy->bands[i]) {
1102 bands_used |= BIT(i);
1103 rate_masks[i] = (u32) -1;
1104 num_bands++;
1105 }
1106 }
1107
1108 ie = kzalloc(num_bands * iebufsz, GFP_KERNEL);
1109 if (!ie) {
1110 ret = -ENOMEM;
1111 goto out;
1112 }
1113
1114 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1115
1116 len = ieee80211_build_preq_ies(local, ie, num_bands * iebufsz,
1117 &sched_scan_ies, req->ie,
1118 req->ie_len, bands_used,
1119 rate_masks, &chandef);
1120
1121 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1122 if (ret == 0) {
1123 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1124 rcu_assign_pointer(local->sched_scan_req, req);
1125 }
1126
1127 kfree(ie);
1128
1129 out:
1130 if (ret) {
1131 /* Clean in case of failure after HW restart or upon resume. */
1132 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1133 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1134 }
1135
1136 return ret;
1137 }
1138
1139 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1140 struct cfg80211_sched_scan_request *req)
1141 {
1142 struct ieee80211_local *local = sdata->local;
1143 int ret;
1144
1145 mutex_lock(&local->mtx);
1146
1147 if (rcu_access_pointer(local->sched_scan_sdata)) {
1148 mutex_unlock(&local->mtx);
1149 return -EBUSY;
1150 }
1151
1152 ret = __ieee80211_request_sched_scan_start(sdata, req);
1153
1154 mutex_unlock(&local->mtx);
1155 return ret;
1156 }
1157
1158 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1159 {
1160 struct ieee80211_sub_if_data *sched_scan_sdata;
1161 int ret = -ENOENT;
1162
1163 mutex_lock(&local->mtx);
1164
1165 if (!local->ops->sched_scan_stop) {
1166 ret = -ENOTSUPP;
1167 goto out;
1168 }
1169
1170 /* We don't want to restart sched scan anymore. */
1171 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1172
1173 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1174 lockdep_is_held(&local->mtx));
1175 if (sched_scan_sdata) {
1176 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1177 if (!ret)
1178 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1179 }
1180 out:
1181 mutex_unlock(&local->mtx);
1182
1183 return ret;
1184 }
1185
1186 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1187 {
1188 struct ieee80211_local *local = hw_to_local(hw);
1189
1190 trace_api_sched_scan_results(local);
1191
1192 cfg80211_sched_scan_results(hw->wiphy);
1193 }
1194 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1195
1196 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1197 {
1198 mutex_lock(&local->mtx);
1199
1200 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1201 mutex_unlock(&local->mtx);
1202 return;
1203 }
1204
1205 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1206
1207 /* If sched scan was aborted by the driver. */
1208 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1209
1210 mutex_unlock(&local->mtx);
1211
1212 cfg80211_sched_scan_stopped(local->hw.wiphy);
1213 }
1214
1215 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1216 {
1217 struct ieee80211_local *local =
1218 container_of(work, struct ieee80211_local,
1219 sched_scan_stopped_work);
1220
1221 ieee80211_sched_scan_end(local);
1222 }
1223
1224 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1225 {
1226 struct ieee80211_local *local = hw_to_local(hw);
1227
1228 trace_api_sched_scan_stopped(local);
1229
1230 /*
1231 * this shouldn't really happen, so for simplicity
1232 * simply ignore it, and let mac80211 reconfigure
1233 * the sched scan later on.
1234 */
1235 if (local->in_reconfig)
1236 return;
1237
1238 schedule_work(&local->sched_scan_stopped_work);
1239 }
1240 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
Linux kernel - Deliverables
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