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Merge tag 'locks-v3.16-2' of git://git.samba.org/jlayton/linux
[linux/fpc-iii.git] / net / mac80211 / scan.c
blobf40661eb75b578dd2e409757331c085d36461723
1 /*
2 * Scanning implementation
3 *
4 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
5 * Copyright 2004, Instant802 Networks, Inc.
6 * Copyright 2005, Devicescape Software, Inc.
7 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
8 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 */
14
15 #include <linux/if_arp.h>
16 #include <linux/etherdevice.h>
17 #include <linux/rtnetlink.h>
18 #include <linux/pm_qos.h>
19 #include <net/sch_generic.h>
20 #include <linux/slab.h>
21 #include <linux/export.h>
22 #include <net/mac80211.h>
23
24 #include "ieee80211_i.h"
25 #include "driver-ops.h"
26 #include "mesh.h"
27
28 #define IEEE80211_PROBE_DELAY (HZ / 33)
29 #define IEEE80211_CHANNEL_TIME (HZ / 33)
30 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
31
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 enum nl80211_bss_scan_width scan_width;
70 s32 signal = 0;
71
72 if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
73 signal = rx_status->signal * 100;
74 else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC)
75 signal = (rx_status->signal * 100) / local->hw.max_signal;
76
77 scan_width = NL80211_BSS_CHAN_WIDTH_20;
78 if (rx_status->flag & RX_FLAG_5MHZ)
79 scan_width = NL80211_BSS_CHAN_WIDTH_5;
80 if (rx_status->flag & RX_FLAG_10MHZ)
81 scan_width = NL80211_BSS_CHAN_WIDTH_10;
82
83 cbss = cfg80211_inform_bss_width_frame(local->hw.wiphy, channel,
84 scan_width, mgmt, len, signal,
85 GFP_ATOMIC);
86 if (!cbss)
87 return NULL;
88
89 bss = (void *)cbss->priv;
90
91 if (beacon)
92 bss->device_ts_beacon = rx_status->device_timestamp;
93 else
94 bss->device_ts_presp = rx_status->device_timestamp;
95
96 if (elems->parse_error) {
97 if (beacon)
98 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
99 else
100 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
101 } else {
102 if (beacon)
103 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
104 else
105 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
106 }
107
108 /* save the ERP value so that it is available at association time */
109 if (elems->erp_info && (!elems->parse_error ||
110 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
111 bss->erp_value = elems->erp_info[0];
112 bss->has_erp_value = true;
113 if (!elems->parse_error)
114 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
115 }
116
117 /* replace old supported rates if we get new values */
118 if (!elems->parse_error ||
119 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
120 srlen = 0;
121 if (elems->supp_rates) {
122 clen = IEEE80211_MAX_SUPP_RATES;
123 if (clen > elems->supp_rates_len)
124 clen = elems->supp_rates_len;
125 memcpy(bss->supp_rates, elems->supp_rates, clen);
126 srlen += clen;
127 }
128 if (elems->ext_supp_rates) {
129 clen = IEEE80211_MAX_SUPP_RATES - srlen;
130 if (clen > elems->ext_supp_rates_len)
131 clen = elems->ext_supp_rates_len;
132 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
133 clen);
134 srlen += clen;
135 }
136 if (srlen) {
137 bss->supp_rates_len = srlen;
138 if (!elems->parse_error)
139 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
140 }
141 }
142
143 if (!elems->parse_error ||
144 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
145 bss->wmm_used = elems->wmm_param || elems->wmm_info;
146 bss->uapsd_supported = is_uapsd_supported(elems);
147 if (!elems->parse_error)
148 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
149 }
150
151 if (beacon) {
152 struct ieee80211_supported_band *sband =
153 local->hw.wiphy->bands[rx_status->band];
154 if (!(rx_status->flag & RX_FLAG_HT) &&
155 !(rx_status->flag & RX_FLAG_VHT))
156 bss->beacon_rate =
157 &sband->bitrates[rx_status->rate_idx];
158 }
159
160 return bss;
161 }
162
163 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
164 {
165 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
166 struct ieee80211_sub_if_data *sdata1, *sdata2;
167 struct ieee80211_mgmt *mgmt = (void *)skb->data;
168 struct ieee80211_bss *bss;
169 u8 *elements;
170 struct ieee80211_channel *channel;
171 size_t baselen;
172 struct ieee802_11_elems elems;
173
174 if (skb->len < 24 ||
175 (!ieee80211_is_probe_resp(mgmt->frame_control) &&
176 !ieee80211_is_beacon(mgmt->frame_control)))
177 return;
178
179 sdata1 = rcu_dereference(local->scan_sdata);
180 sdata2 = rcu_dereference(local->sched_scan_sdata);
181
182 if (likely(!sdata1 && !sdata2))
183 return;
184
185 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
186 /* ignore ProbeResp to foreign address */
187 if ((!sdata1 || !ether_addr_equal(mgmt->da, sdata1->vif.addr)) &&
188 (!sdata2 || !ether_addr_equal(mgmt->da, sdata2->vif.addr)))
189 return;
190
191 elements = mgmt->u.probe_resp.variable;
192 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
193 } else {
194 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
195 elements = mgmt->u.beacon.variable;
196 }
197
198 if (baselen > skb->len)
199 return;
200
201 ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems);
202
203 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
204
205 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
206 return;
207
208 bss = ieee80211_bss_info_update(local, rx_status,
209 mgmt, skb->len, &elems,
210 channel);
211 if (bss)
212 ieee80211_rx_bss_put(local, bss);
213 }
214
215 static void
216 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
217 enum nl80211_bss_scan_width scan_width)
218 {
219 memset(chandef, 0, sizeof(*chandef));
220 switch (scan_width) {
221 case NL80211_BSS_CHAN_WIDTH_5:
222 chandef->width = NL80211_CHAN_WIDTH_5;
223 break;
224 case NL80211_BSS_CHAN_WIDTH_10:
225 chandef->width = NL80211_CHAN_WIDTH_10;
226 break;
227 default:
228 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
229 break;
230 }
231 }
232
233 /* return false if no more work */
234 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
235 {
236 struct cfg80211_scan_request *req = local->scan_req;
237 struct cfg80211_chan_def chandef;
238 enum ieee80211_band band;
239 int i, ielen, n_chans;
240
241 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
242 return false;
243
244 do {
245 if (local->hw_scan_band == IEEE80211_NUM_BANDS)
246 return false;
247
248 band = local->hw_scan_band;
249 n_chans = 0;
250 for (i = 0; i < req->n_channels; i++) {
251 if (req->channels[i]->band == band) {
252 local->hw_scan_req->channels[n_chans] =
253 req->channels[i];
254 n_chans++;
255 }
256 }
257
258 local->hw_scan_band++;
259 } while (!n_chans);
260
261 local->hw_scan_req->n_channels = n_chans;
262 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
263
264 ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie,
265 local->hw_scan_ies_bufsize,
266 req->ie, req->ie_len, band,
267 req->rates[band], &chandef);
268 local->hw_scan_req->ie_len = ielen;
269 local->hw_scan_req->no_cck = req->no_cck;
270
271 return true;
272 }
273
274 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
275 {
276 struct ieee80211_local *local = hw_to_local(hw);
277 bool hw_scan = local->ops->hw_scan;
278 bool was_scanning = local->scanning;
279
280 lockdep_assert_held(&local->mtx);
281
282 /*
283 * It's ok to abort a not-yet-running scan (that
284 * we have one at all will be verified by checking
285 * local->scan_req next), but not to complete it
286 * successfully.
287 */
288 if (WARN_ON(!local->scanning && !aborted))
289 aborted = true;
290
291 if (WARN_ON(!local->scan_req))
292 return;
293
294 if (hw_scan && !aborted && ieee80211_prep_hw_scan(local)) {
295 int rc;
296
297 rc = drv_hw_scan(local,
298 rcu_dereference_protected(local->scan_sdata,
299 lockdep_is_held(&local->mtx)),
300 local->hw_scan_req);
301
302 if (rc == 0)
303 return;
304 }
305
306 kfree(local->hw_scan_req);
307 local->hw_scan_req = NULL;
308
309 if (local->scan_req != local->int_scan_req)
310 cfg80211_scan_done(local->scan_req, aborted);
311 local->scan_req = NULL;
312 RCU_INIT_POINTER(local->scan_sdata, NULL);
313
314 local->scanning = 0;
315 local->scan_chandef.chan = NULL;
316
317 /* Set power back to normal operating levels. */
318 ieee80211_hw_config(local, 0);
319
320 if (!hw_scan) {
321 ieee80211_configure_filter(local);
322 drv_sw_scan_complete(local);
323 ieee80211_offchannel_return(local);
324 }
325
326 ieee80211_recalc_idle(local);
327
328 ieee80211_mlme_notify_scan_completed(local);
329 ieee80211_ibss_notify_scan_completed(local);
330 ieee80211_mesh_notify_scan_completed(local);
331 if (was_scanning)
332 ieee80211_start_next_roc(local);
333 }
334
335 void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
336 {
337 struct ieee80211_local *local = hw_to_local(hw);
338
339 trace_api_scan_completed(local, aborted);
340
341 set_bit(SCAN_COMPLETED, &local->scanning);
342 if (aborted)
343 set_bit(SCAN_ABORTED, &local->scanning);
344 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
345 }
346 EXPORT_SYMBOL(ieee80211_scan_completed);
347
348 static int ieee80211_start_sw_scan(struct ieee80211_local *local)
349 {
350 /* Software scan is not supported in multi-channel cases */
351 if (local->use_chanctx)
352 return -EOPNOTSUPP;
353
354 /*
355 * Hardware/driver doesn't support hw_scan, so use software
356 * scanning instead. First send a nullfunc frame with power save
357 * bit on so that AP will buffer the frames for us while we are not
358 * listening, then send probe requests to each channel and wait for
359 * the responses. After all channels are scanned, tune back to the
360 * original channel and send a nullfunc frame with power save bit
361 * off to trigger the AP to send us all the buffered frames.
362 *
363 * Note that while local->sw_scanning is true everything else but
364 * nullfunc frames and probe requests will be dropped in
365 * ieee80211_tx_h_check_assoc().
366 */
367 drv_sw_scan_start(local);
368
369 local->leave_oper_channel_time = jiffies;
370 local->next_scan_state = SCAN_DECISION;
371 local->scan_channel_idx = 0;
372
373 ieee80211_offchannel_stop_vifs(local);
374
375 /* ensure nullfunc is transmitted before leaving operating channel */
376 ieee80211_flush_queues(local, NULL);
377
378 ieee80211_configure_filter(local);
379
380 /* We need to set power level at maximum rate for scanning. */
381 ieee80211_hw_config(local, 0);
382
383 ieee80211_queue_delayed_work(&local->hw,
384 &local->scan_work, 0);
385
386 return 0;
387 }
388
389 static bool ieee80211_can_scan(struct ieee80211_local *local,
390 struct ieee80211_sub_if_data *sdata)
391 {
392 if (local->radar_detect_enabled)
393 return false;
394
395 if (!list_empty(&local->roc_list))
396 return false;
397
398 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
399 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
400 return false;
401
402 return true;
403 }
404
405 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
406 {
407 lockdep_assert_held(&local->mtx);
408
409 if (!local->scan_req || local->scanning)
410 return;
411
412 if (!ieee80211_can_scan(local,
413 rcu_dereference_protected(
414 local->scan_sdata,
415 lockdep_is_held(&local->mtx))))
416 return;
417
418 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
419 round_jiffies_relative(0));
420 }
421
422 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
423 unsigned long *next_delay)
424 {
425 int i;
426 struct ieee80211_sub_if_data *sdata;
427 enum ieee80211_band band = local->hw.conf.chandef.chan->band;
428 u32 tx_flags;
429
430 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
431 if (local->scan_req->no_cck)
432 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
433
434 sdata = rcu_dereference_protected(local->scan_sdata,
435 lockdep_is_held(&local->mtx));
436
437 for (i = 0; i < local->scan_req->n_ssids; i++)
438 ieee80211_send_probe_req(
439 sdata, NULL,
440 local->scan_req->ssids[i].ssid,
441 local->scan_req->ssids[i].ssid_len,
442 local->scan_req->ie, local->scan_req->ie_len,
443 local->scan_req->rates[band], false,
444 tx_flags, local->hw.conf.chandef.chan, true);
445
446 /*
447 * After sending probe requests, wait for probe responses
448 * on the channel.
449 */
450 *next_delay = IEEE80211_CHANNEL_TIME;
451 local->next_scan_state = SCAN_DECISION;
452 }
453
454 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
455 struct cfg80211_scan_request *req)
456 {
457 struct ieee80211_local *local = sdata->local;
458 int rc;
459
460 lockdep_assert_held(&local->mtx);
461
462 if (local->scan_req)
463 return -EBUSY;
464
465 if (!ieee80211_can_scan(local, sdata)) {
466 /* wait for the work to finish/time out */
467 local->scan_req = req;
468 rcu_assign_pointer(local->scan_sdata, sdata);
469 return 0;
470 }
471
472 if (local->ops->hw_scan) {
473 u8 *ies;
474
475 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
476 local->hw_scan_req = kmalloc(
477 sizeof(*local->hw_scan_req) +
478 req->n_channels * sizeof(req->channels[0]) +
479 local->hw_scan_ies_bufsize, GFP_KERNEL);
480 if (!local->hw_scan_req)
481 return -ENOMEM;
482
483 local->hw_scan_req->ssids = req->ssids;
484 local->hw_scan_req->n_ssids = req->n_ssids;
485 ies = (u8 *)local->hw_scan_req +
486 sizeof(*local->hw_scan_req) +
487 req->n_channels * sizeof(req->channels[0]);
488 local->hw_scan_req->ie = ies;
489 local->hw_scan_req->flags = req->flags;
490
491 local->hw_scan_band = 0;
492
493 /*
494 * After allocating local->hw_scan_req, we must
495 * go through until ieee80211_prep_hw_scan(), so
496 * anything that might be changed here and leave
497 * this function early must not go after this
498 * allocation.
499 */
500 }
501
502 local->scan_req = req;
503 rcu_assign_pointer(local->scan_sdata, sdata);
504
505 if (local->ops->hw_scan) {
506 __set_bit(SCAN_HW_SCANNING, &local->scanning);
507 } else if ((req->n_channels == 1) &&
508 (req->channels[0] == local->_oper_chandef.chan)) {
509 /*
510 * If we are scanning only on the operating channel
511 * then we do not need to stop normal activities
512 */
513 unsigned long next_delay;
514
515 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
516
517 ieee80211_recalc_idle(local);
518
519 /* Notify driver scan is starting, keep order of operations
520 * same as normal software scan, in case that matters. */
521 drv_sw_scan_start(local);
522
523 ieee80211_configure_filter(local); /* accept probe-responses */
524
525 /* We need to ensure power level is at max for scanning. */
526 ieee80211_hw_config(local, 0);
527
528 if ((req->channels[0]->flags &
529 IEEE80211_CHAN_NO_IR) ||
530 !local->scan_req->n_ssids) {
531 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
532 } else {
533 ieee80211_scan_state_send_probe(local, &next_delay);
534 next_delay = IEEE80211_CHANNEL_TIME;
535 }
536
537 /* Now, just wait a bit and we are all done! */
538 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
539 next_delay);
540 return 0;
541 } else {
542 /* Do normal software scan */
543 __set_bit(SCAN_SW_SCANNING, &local->scanning);
544 }
545
546 ieee80211_recalc_idle(local);
547
548 if (local->ops->hw_scan) {
549 WARN_ON(!ieee80211_prep_hw_scan(local));
550 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
551 } else
552 rc = ieee80211_start_sw_scan(local);
553
554 if (rc) {
555 kfree(local->hw_scan_req);
556 local->hw_scan_req = NULL;
557 local->scanning = 0;
558
559 ieee80211_recalc_idle(local);
560
561 local->scan_req = NULL;
562 RCU_INIT_POINTER(local->scan_sdata, NULL);
563 }
564
565 return rc;
566 }
567
568 static unsigned long
569 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
570 {
571 /*
572 * TODO: channel switching also consumes quite some time,
573 * add that delay as well to get a better estimation
574 */
575 if (chan->flags & IEEE80211_CHAN_NO_IR)
576 return IEEE80211_PASSIVE_CHANNEL_TIME;
577 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
578 }
579
580 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
581 unsigned long *next_delay)
582 {
583 bool associated = false;
584 bool tx_empty = true;
585 bool bad_latency;
586 struct ieee80211_sub_if_data *sdata;
587 struct ieee80211_channel *next_chan;
588 enum mac80211_scan_state next_scan_state;
589
590 /*
591 * check if at least one STA interface is associated,
592 * check if at least one STA interface has pending tx frames
593 * and grab the lowest used beacon interval
594 */
595 mutex_lock(&local->iflist_mtx);
596 list_for_each_entry(sdata, &local->interfaces, list) {
597 if (!ieee80211_sdata_running(sdata))
598 continue;
599
600 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
601 if (sdata->u.mgd.associated) {
602 associated = true;
603
604 if (!qdisc_all_tx_empty(sdata->dev)) {
605 tx_empty = false;
606 break;
607 }
608 }
609 }
610 }
611 mutex_unlock(&local->iflist_mtx);
612
613 next_chan = local->scan_req->channels[local->scan_channel_idx];
614
615 /*
616 * we're currently scanning a different channel, let's
617 * see if we can scan another channel without interfering
618 * with the current traffic situation.
619 *
620 * Keep good latency, do not stay off-channel more than 125 ms.
621 */
622
623 bad_latency = time_after(jiffies +
624 ieee80211_scan_get_channel_time(next_chan),
625 local->leave_oper_channel_time + HZ / 8);
626
627 if (associated && !tx_empty) {
628 if (local->scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
629 next_scan_state = SCAN_ABORT;
630 else
631 next_scan_state = SCAN_SUSPEND;
632 } else if (associated && bad_latency) {
633 next_scan_state = SCAN_SUSPEND;
634 } else {
635 next_scan_state = SCAN_SET_CHANNEL;
636 }
637
638 local->next_scan_state = next_scan_state;
639
640 *next_delay = 0;
641 }
642
643 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
644 unsigned long *next_delay)
645 {
646 int skip;
647 struct ieee80211_channel *chan;
648 enum nl80211_bss_scan_width oper_scan_width;
649
650 skip = 0;
651 chan = local->scan_req->channels[local->scan_channel_idx];
652
653 local->scan_chandef.chan = chan;
654 local->scan_chandef.center_freq1 = chan->center_freq;
655 local->scan_chandef.center_freq2 = 0;
656 switch (local->scan_req->scan_width) {
657 case NL80211_BSS_CHAN_WIDTH_5:
658 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
659 break;
660 case NL80211_BSS_CHAN_WIDTH_10:
661 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
662 break;
663 case NL80211_BSS_CHAN_WIDTH_20:
664 /* If scanning on oper channel, use whatever channel-type
665 * is currently in use.
666 */
667 oper_scan_width = cfg80211_chandef_to_scan_width(
668 &local->_oper_chandef);
669 if (chan == local->_oper_chandef.chan &&
670 oper_scan_width == local->scan_req->scan_width)
671 local->scan_chandef = local->_oper_chandef;
672 else
673 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
674 break;
675 }
676
677 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
678 skip = 1;
679
680 /* advance state machine to next channel/band */
681 local->scan_channel_idx++;
682
683 if (skip) {
684 /* if we skip this channel return to the decision state */
685 local->next_scan_state = SCAN_DECISION;
686 return;
687 }
688
689 /*
690 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
691 * (which unfortunately doesn't say _why_ step a) is done,
692 * but it waits for the probe delay or until a frame is
693 * received - and the received frame would update the NAV).
694 * For now, we do not support waiting until a frame is
695 * received.
696 *
697 * In any case, it is not necessary for a passive scan.
698 */
699 if (chan->flags & IEEE80211_CHAN_NO_IR ||
700 !local->scan_req->n_ssids) {
701 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
702 local->next_scan_state = SCAN_DECISION;
703 return;
704 }
705
706 /* active scan, send probes */
707 *next_delay = IEEE80211_PROBE_DELAY;
708 local->next_scan_state = SCAN_SEND_PROBE;
709 }
710
711 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
712 unsigned long *next_delay)
713 {
714 /* switch back to the operating channel */
715 local->scan_chandef.chan = NULL;
716 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
717
718 /* disable PS */
719 ieee80211_offchannel_return(local);
720
721 *next_delay = HZ / 5;
722 /* afterwards, resume scan & go to next channel */
723 local->next_scan_state = SCAN_RESUME;
724 }
725
726 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
727 unsigned long *next_delay)
728 {
729 ieee80211_offchannel_stop_vifs(local);
730
731 if (local->ops->flush) {
732 ieee80211_flush_queues(local, NULL);
733 *next_delay = 0;
734 } else
735 *next_delay = HZ / 10;
736
737 /* remember when we left the operating channel */
738 local->leave_oper_channel_time = jiffies;
739
740 /* advance to the next channel to be scanned */
741 local->next_scan_state = SCAN_SET_CHANNEL;
742 }
743
744 void ieee80211_scan_work(struct work_struct *work)
745 {
746 struct ieee80211_local *local =
747 container_of(work, struct ieee80211_local, scan_work.work);
748 struct ieee80211_sub_if_data *sdata;
749 unsigned long next_delay = 0;
750 bool aborted;
751
752 mutex_lock(&local->mtx);
753
754 sdata = rcu_dereference_protected(local->scan_sdata,
755 lockdep_is_held(&local->mtx));
756
757 /* When scanning on-channel, the first-callback means completed. */
758 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
759 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
760 goto out_complete;
761 }
762
763 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
764 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
765 goto out_complete;
766 }
767
768 if (!sdata || !local->scan_req)
769 goto out;
770
771 if (local->scan_req && !local->scanning) {
772 struct cfg80211_scan_request *req = local->scan_req;
773 int rc;
774
775 local->scan_req = NULL;
776 RCU_INIT_POINTER(local->scan_sdata, NULL);
777
778 rc = __ieee80211_start_scan(sdata, req);
779 if (rc) {
780 /* need to complete scan in cfg80211 */
781 local->scan_req = req;
782 aborted = true;
783 goto out_complete;
784 } else
785 goto out;
786 }
787
788 /*
789 * as long as no delay is required advance immediately
790 * without scheduling a new work
791 */
792 do {
793 if (!ieee80211_sdata_running(sdata)) {
794 aborted = true;
795 goto out_complete;
796 }
797
798 switch (local->next_scan_state) {
799 case SCAN_DECISION:
800 /* if no more bands/channels left, complete scan */
801 if (local->scan_channel_idx >= local->scan_req->n_channels) {
802 aborted = false;
803 goto out_complete;
804 }
805 ieee80211_scan_state_decision(local, &next_delay);
806 break;
807 case SCAN_SET_CHANNEL:
808 ieee80211_scan_state_set_channel(local, &next_delay);
809 break;
810 case SCAN_SEND_PROBE:
811 ieee80211_scan_state_send_probe(local, &next_delay);
812 break;
813 case SCAN_SUSPEND:
814 ieee80211_scan_state_suspend(local, &next_delay);
815 break;
816 case SCAN_RESUME:
817 ieee80211_scan_state_resume(local, &next_delay);
818 break;
819 case SCAN_ABORT:
820 aborted = true;
821 goto out_complete;
822 }
823 } while (next_delay == 0);
824
825 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
826 goto out;
827
828 out_complete:
829 __ieee80211_scan_completed(&local->hw, aborted);
830 out:
831 mutex_unlock(&local->mtx);
832 }
833
834 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
835 struct cfg80211_scan_request *req)
836 {
837 int res;
838
839 mutex_lock(&sdata->local->mtx);
840 res = __ieee80211_start_scan(sdata, req);
841 mutex_unlock(&sdata->local->mtx);
842
843 return res;
844 }
845
846 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
847 const u8 *ssid, u8 ssid_len,
848 struct ieee80211_channel *chan,
849 enum nl80211_bss_scan_width scan_width)
850 {
851 struct ieee80211_local *local = sdata->local;
852 int ret = -EBUSY;
853 enum ieee80211_band band;
854
855 mutex_lock(&local->mtx);
856
857 /* busy scanning */
858 if (local->scan_req)
859 goto unlock;
860
861 /* fill internal scan request */
862 if (!chan) {
863 int i, max_n;
864 int n_ch = 0;
865
866 for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
867 if (!local->hw.wiphy->bands[band])
868 continue;
869
870 max_n = local->hw.wiphy->bands[band]->n_channels;
871 for (i = 0; i < max_n; i++) {
872 struct ieee80211_channel *tmp_ch =
873 &local->hw.wiphy->bands[band]->channels[i];
874
875 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
876 IEEE80211_CHAN_DISABLED))
877 continue;
878
879 local->int_scan_req->channels[n_ch] = tmp_ch;
880 n_ch++;
881 }
882 }
883
884 if (WARN_ON_ONCE(n_ch == 0))
885 goto unlock;
886
887 local->int_scan_req->n_channels = n_ch;
888 } else {
889 if (WARN_ON_ONCE(chan->flags & (IEEE80211_CHAN_NO_IR |
890 IEEE80211_CHAN_DISABLED)))
891 goto unlock;
892
893 local->int_scan_req->channels[0] = chan;
894 local->int_scan_req->n_channels = 1;
895 }
896
897 local->int_scan_req->ssids = &local->scan_ssid;
898 local->int_scan_req->n_ssids = 1;
899 local->int_scan_req->scan_width = scan_width;
900 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
901 local->int_scan_req->ssids[0].ssid_len = ssid_len;
902
903 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
904 unlock:
905 mutex_unlock(&local->mtx);
906 return ret;
907 }
908
909 /*
910 * Only call this function when a scan can't be queued -- under RTNL.
911 */
912 void ieee80211_scan_cancel(struct ieee80211_local *local)
913 {
914 /*
915 * We are canceling software scan, or deferred scan that was not
916 * yet really started (see __ieee80211_start_scan ).
917 *
918 * Regarding hardware scan:
919 * - we can not call __ieee80211_scan_completed() as when
920 * SCAN_HW_SCANNING bit is set this function change
921 * local->hw_scan_req to operate on 5G band, what race with
922 * driver which can use local->hw_scan_req
923 *
924 * - we can not cancel scan_work since driver can schedule it
925 * by ieee80211_scan_completed(..., true) to finish scan
926 *
927 * Hence we only call the cancel_hw_scan() callback, but the low-level
928 * driver is still responsible for calling ieee80211_scan_completed()
929 * after the scan was completed/aborted.
930 */
931
932 mutex_lock(&local->mtx);
933 if (!local->scan_req)
934 goto out;
935
936 /*
937 * We have a scan running and the driver already reported completion,
938 * but the worker hasn't run yet or is stuck on the mutex - mark it as
939 * cancelled.
940 */
941 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
942 test_bit(SCAN_COMPLETED, &local->scanning)) {
943 set_bit(SCAN_HW_CANCELLED, &local->scanning);
944 goto out;
945 }
946
947 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
948 /*
949 * Make sure that __ieee80211_scan_completed doesn't trigger a
950 * scan on another band.
951 */
952 set_bit(SCAN_HW_CANCELLED, &local->scanning);
953 if (local->ops->cancel_hw_scan)
954 drv_cancel_hw_scan(local,
955 rcu_dereference_protected(local->scan_sdata,
956 lockdep_is_held(&local->mtx)));
957 goto out;
958 }
959
960 /*
961 * If the work is currently running, it must be blocked on
962 * the mutex, but we'll set scan_sdata = NULL and it'll
963 * simply exit once it acquires the mutex.
964 */
965 cancel_delayed_work(&local->scan_work);
966 /* and clean up */
967 __ieee80211_scan_completed(&local->hw, true);
968 out:
969 mutex_unlock(&local->mtx);
970 }
971
972 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
973 struct cfg80211_sched_scan_request *req)
974 {
975 struct ieee80211_local *local = sdata->local;
976 struct ieee80211_sched_scan_ies sched_scan_ies = {};
977 struct cfg80211_chan_def chandef;
978 int ret, i, iebufsz;
979
980 iebufsz = local->scan_ies_len + req->ie_len;
981
982 lockdep_assert_held(&local->mtx);
983
984 if (!local->ops->sched_scan_start)
985 return -ENOTSUPP;
986
987 for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
988 if (!local->hw.wiphy->bands[i])
989 continue;
990
991 sched_scan_ies.ie[i] = kzalloc(iebufsz, GFP_KERNEL);
992 if (!sched_scan_ies.ie[i]) {
993 ret = -ENOMEM;
994 goto out_free;
995 }
996
997 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
998
999 sched_scan_ies.len[i] =
1000 ieee80211_build_preq_ies(local, sched_scan_ies.ie[i],
1001 iebufsz, req->ie, req->ie_len,
1002 i, (u32) -1, &chandef);
1003 }
1004
1005 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1006 if (ret == 0) {
1007 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1008 local->sched_scan_req = req;
1009 }
1010
1011 out_free:
1012 while (i > 0)
1013 kfree(sched_scan_ies.ie[--i]);
1014
1015 if (ret) {
1016 /* Clean in case of failure after HW restart or upon resume. */
1017 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1018 local->sched_scan_req = NULL;
1019 }
1020
1021 return ret;
1022 }
1023
1024 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1025 struct cfg80211_sched_scan_request *req)
1026 {
1027 struct ieee80211_local *local = sdata->local;
1028 int ret;
1029
1030 mutex_lock(&local->mtx);
1031
1032 if (rcu_access_pointer(local->sched_scan_sdata)) {
1033 mutex_unlock(&local->mtx);
1034 return -EBUSY;
1035 }
1036
1037 ret = __ieee80211_request_sched_scan_start(sdata, req);
1038
1039 mutex_unlock(&local->mtx);
1040 return ret;
1041 }
1042
1043 int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata)
1044 {
1045 struct ieee80211_local *local = sdata->local;
1046 int ret = 0;
1047
1048 mutex_lock(&local->mtx);
1049
1050 if (!local->ops->sched_scan_stop) {
1051 ret = -ENOTSUPP;
1052 goto out;
1053 }
1054
1055 /* We don't want to restart sched scan anymore. */
1056 local->sched_scan_req = NULL;
1057
1058 if (rcu_access_pointer(local->sched_scan_sdata)) {
1059 ret = drv_sched_scan_stop(local, sdata);
1060 if (!ret)
1061 rcu_assign_pointer(local->sched_scan_sdata, NULL);
1062 }
1063 out:
1064 mutex_unlock(&local->mtx);
1065
1066 return ret;
1067 }
1068
1069 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1070 {
1071 struct ieee80211_local *local = hw_to_local(hw);
1072
1073 trace_api_sched_scan_results(local);
1074
1075 cfg80211_sched_scan_results(hw->wiphy);
1076 }
1077 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1078
1079 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1080 {
1081 mutex_lock(&local->mtx);
1082
1083 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1084 mutex_unlock(&local->mtx);
1085 return;
1086 }
1087
1088 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1089
1090 /* If sched scan was aborted by the driver. */
1091 local->sched_scan_req = NULL;
1092
1093 mutex_unlock(&local->mtx);
1094
1095 cfg80211_sched_scan_stopped(local->hw.wiphy);
1096 }
1097
1098 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1099 {
1100 struct ieee80211_local *local =
1101 container_of(work, struct ieee80211_local,
1102 sched_scan_stopped_work);
1103
1104 ieee80211_sched_scan_end(local);
1105 }
1106
1107 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1108 {
1109 struct ieee80211_local *local = hw_to_local(hw);
1110
1111 trace_api_sched_scan_stopped(local);
1112
1113 schedule_work(&local->sched_scan_stopped_work);
1114 }
1115 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
Linux with added FPC-III support