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clk: shmobile: add CPG driver for rz-platforms
[linux-2.6/btrfs-unstable.git] / net / mac80211 / scan.c
blob88c81616f8f758595e90cced1d503448ce6ba969
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_assign_pointer(local->scan_sdata, NULL);
313
314 local->scanning = 0;
315 local->scan_chandef.chan = NULL;
316
317 /* Set power back to normal operating levels. */
318 ieee80211_hw_config(local, 0);
319
320 if (!hw_scan) {
321 ieee80211_configure_filter(local);
322 drv_sw_scan_complete(local);
323 ieee80211_offchannel_return(local);
324 }
325
326 ieee80211_recalc_idle(local);
327
328 ieee80211_mlme_notify_scan_completed(local);
329 ieee80211_ibss_notify_scan_completed(local);
330 ieee80211_mesh_notify_scan_completed(local);
331 if (was_scanning)
332 ieee80211_start_next_roc(local);
333 }
334
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 = 2 + IEEE80211_MAX_SSID_LEN +
476 local->scan_ies_len +
477 req->ie_len;
478 local->hw_scan_req = kmalloc(
479 sizeof(*local->hw_scan_req) +
480 req->n_channels * sizeof(req->channels[0]) +
481 local->hw_scan_ies_bufsize, GFP_KERNEL);
482 if (!local->hw_scan_req)
483 return -ENOMEM;
484
485 local->hw_scan_req->ssids = req->ssids;
486 local->hw_scan_req->n_ssids = req->n_ssids;
487 ies = (u8 *)local->hw_scan_req +
488 sizeof(*local->hw_scan_req) +
489 req->n_channels * sizeof(req->channels[0]);
490 local->hw_scan_req->ie = ies;
491 local->hw_scan_req->flags = req->flags;
492
493 local->hw_scan_band = 0;
494
495 /*
496 * After allocating local->hw_scan_req, we must
497 * go through until ieee80211_prep_hw_scan(), so
498 * anything that might be changed here and leave
499 * this function early must not go after this
500 * allocation.
501 */
502 }
503
504 local->scan_req = req;
505 rcu_assign_pointer(local->scan_sdata, sdata);
506
507 if (local->ops->hw_scan) {
508 __set_bit(SCAN_HW_SCANNING, &local->scanning);
509 } else if ((req->n_channels == 1) &&
510 (req->channels[0] == local->_oper_chandef.chan)) {
511 /*
512 * If we are scanning only on the operating channel
513 * then we do not need to stop normal activities
514 */
515 unsigned long next_delay;
516
517 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
518
519 ieee80211_recalc_idle(local);
520
521 /* Notify driver scan is starting, keep order of operations
522 * same as normal software scan, in case that matters. */
523 drv_sw_scan_start(local);
524
525 ieee80211_configure_filter(local); /* accept probe-responses */
526
527 /* We need to ensure power level is at max for scanning. */
528 ieee80211_hw_config(local, 0);
529
530 if ((req->channels[0]->flags &
531 IEEE80211_CHAN_NO_IR) ||
532 !local->scan_req->n_ssids) {
533 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
534 } else {
535 ieee80211_scan_state_send_probe(local, &next_delay);
536 next_delay = IEEE80211_CHANNEL_TIME;
537 }
538
539 /* Now, just wait a bit and we are all done! */
540 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
541 next_delay);
542 return 0;
543 } else {
544 /* Do normal software scan */
545 __set_bit(SCAN_SW_SCANNING, &local->scanning);
546 }
547
548 ieee80211_recalc_idle(local);
549
550 if (local->ops->hw_scan) {
551 WARN_ON(!ieee80211_prep_hw_scan(local));
552 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
553 } else
554 rc = ieee80211_start_sw_scan(local);
555
556 if (rc) {
557 kfree(local->hw_scan_req);
558 local->hw_scan_req = NULL;
559 local->scanning = 0;
560
561 ieee80211_recalc_idle(local);
562
563 local->scan_req = NULL;
564 rcu_assign_pointer(local->scan_sdata, NULL);
565 }
566
567 return rc;
568 }
569
570 static unsigned long
571 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
572 {
573 /*
574 * TODO: channel switching also consumes quite some time,
575 * add that delay as well to get a better estimation
576 */
577 if (chan->flags & IEEE80211_CHAN_NO_IR)
578 return IEEE80211_PASSIVE_CHANNEL_TIME;
579 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
580 }
581
582 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
583 unsigned long *next_delay)
584 {
585 bool associated = false;
586 bool tx_empty = true;
587 bool bad_latency;
588 struct ieee80211_sub_if_data *sdata;
589 struct ieee80211_channel *next_chan;
590 enum mac80211_scan_state next_scan_state;
591
592 /*
593 * check if at least one STA interface is associated,
594 * check if at least one STA interface has pending tx frames
595 * and grab the lowest used beacon interval
596 */
597 mutex_lock(&local->iflist_mtx);
598 list_for_each_entry(sdata, &local->interfaces, list) {
599 if (!ieee80211_sdata_running(sdata))
600 continue;
601
602 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
603 if (sdata->u.mgd.associated) {
604 associated = true;
605
606 if (!qdisc_all_tx_empty(sdata->dev)) {
607 tx_empty = false;
608 break;
609 }
610 }
611 }
612 }
613 mutex_unlock(&local->iflist_mtx);
614
615 next_chan = local->scan_req->channels[local->scan_channel_idx];
616
617 /*
618 * we're currently scanning a different channel, let's
619 * see if we can scan another channel without interfering
620 * with the current traffic situation.
621 *
622 * Keep good latency, do not stay off-channel more than 125 ms.
623 */
624
625 bad_latency = time_after(jiffies +
626 ieee80211_scan_get_channel_time(next_chan),
627 local->leave_oper_channel_time + HZ / 8);
628
629 if (associated && !tx_empty) {
630 if (local->scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
631 next_scan_state = SCAN_ABORT;
632 else
633 next_scan_state = SCAN_SUSPEND;
634 } else if (associated && bad_latency) {
635 next_scan_state = SCAN_SUSPEND;
636 } else {
637 next_scan_state = SCAN_SET_CHANNEL;
638 }
639
640 local->next_scan_state = next_scan_state;
641
642 *next_delay = 0;
643 }
644
645 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
646 unsigned long *next_delay)
647 {
648 int skip;
649 struct ieee80211_channel *chan;
650 enum nl80211_bss_scan_width oper_scan_width;
651
652 skip = 0;
653 chan = local->scan_req->channels[local->scan_channel_idx];
654
655 local->scan_chandef.chan = chan;
656 local->scan_chandef.center_freq1 = chan->center_freq;
657 local->scan_chandef.center_freq2 = 0;
658 switch (local->scan_req->scan_width) {
659 case NL80211_BSS_CHAN_WIDTH_5:
660 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
661 break;
662 case NL80211_BSS_CHAN_WIDTH_10:
663 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
664 break;
665 case NL80211_BSS_CHAN_WIDTH_20:
666 /* If scanning on oper channel, use whatever channel-type
667 * is currently in use.
668 */
669 oper_scan_width = cfg80211_chandef_to_scan_width(
670 &local->_oper_chandef);
671 if (chan == local->_oper_chandef.chan &&
672 oper_scan_width == local->scan_req->scan_width)
673 local->scan_chandef = local->_oper_chandef;
674 else
675 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
676 break;
677 }
678
679 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
680 skip = 1;
681
682 /* advance state machine to next channel/band */
683 local->scan_channel_idx++;
684
685 if (skip) {
686 /* if we skip this channel return to the decision state */
687 local->next_scan_state = SCAN_DECISION;
688 return;
689 }
690
691 /*
692 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
693 * (which unfortunately doesn't say _why_ step a) is done,
694 * but it waits for the probe delay or until a frame is
695 * received - and the received frame would update the NAV).
696 * For now, we do not support waiting until a frame is
697 * received.
698 *
699 * In any case, it is not necessary for a passive scan.
700 */
701 if (chan->flags & IEEE80211_CHAN_NO_IR ||
702 !local->scan_req->n_ssids) {
703 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
704 local->next_scan_state = SCAN_DECISION;
705 return;
706 }
707
708 /* active scan, send probes */
709 *next_delay = IEEE80211_PROBE_DELAY;
710 local->next_scan_state = SCAN_SEND_PROBE;
711 }
712
713 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
714 unsigned long *next_delay)
715 {
716 /* switch back to the operating channel */
717 local->scan_chandef.chan = NULL;
718 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
719
720 /* disable PS */
721 ieee80211_offchannel_return(local);
722
723 *next_delay = HZ / 5;
724 /* afterwards, resume scan & go to next channel */
725 local->next_scan_state = SCAN_RESUME;
726 }
727
728 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
729 unsigned long *next_delay)
730 {
731 ieee80211_offchannel_stop_vifs(local);
732
733 if (local->ops->flush) {
734 ieee80211_flush_queues(local, NULL);
735 *next_delay = 0;
736 } else
737 *next_delay = HZ / 10;
738
739 /* remember when we left the operating channel */
740 local->leave_oper_channel_time = jiffies;
741
742 /* advance to the next channel to be scanned */
743 local->next_scan_state = SCAN_SET_CHANNEL;
744 }
745
746 void ieee80211_scan_work(struct work_struct *work)
747 {
748 struct ieee80211_local *local =
749 container_of(work, struct ieee80211_local, scan_work.work);
750 struct ieee80211_sub_if_data *sdata;
751 unsigned long next_delay = 0;
752 bool aborted;
753
754 mutex_lock(&local->mtx);
755
756 sdata = rcu_dereference_protected(local->scan_sdata,
757 lockdep_is_held(&local->mtx));
758
759 /* When scanning on-channel, the first-callback means completed. */
760 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
761 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
762 goto out_complete;
763 }
764
765 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
766 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
767 goto out_complete;
768 }
769
770 if (!sdata || !local->scan_req)
771 goto out;
772
773 if (local->scan_req && !local->scanning) {
774 struct cfg80211_scan_request *req = local->scan_req;
775 int rc;
776
777 local->scan_req = NULL;
778 rcu_assign_pointer(local->scan_sdata, NULL);
779
780 rc = __ieee80211_start_scan(sdata, req);
781 if (rc) {
782 /* need to complete scan in cfg80211 */
783 local->scan_req = req;
784 aborted = true;
785 goto out_complete;
786 } else
787 goto out;
788 }
789
790 /*
791 * as long as no delay is required advance immediately
792 * without scheduling a new work
793 */
794 do {
795 if (!ieee80211_sdata_running(sdata)) {
796 aborted = true;
797 goto out_complete;
798 }
799
800 switch (local->next_scan_state) {
801 case SCAN_DECISION:
802 /* if no more bands/channels left, complete scan */
803 if (local->scan_channel_idx >= local->scan_req->n_channels) {
804 aborted = false;
805 goto out_complete;
806 }
807 ieee80211_scan_state_decision(local, &next_delay);
808 break;
809 case SCAN_SET_CHANNEL:
810 ieee80211_scan_state_set_channel(local, &next_delay);
811 break;
812 case SCAN_SEND_PROBE:
813 ieee80211_scan_state_send_probe(local, &next_delay);
814 break;
815 case SCAN_SUSPEND:
816 ieee80211_scan_state_suspend(local, &next_delay);
817 break;
818 case SCAN_RESUME:
819 ieee80211_scan_state_resume(local, &next_delay);
820 break;
821 case SCAN_ABORT:
822 aborted = true;
823 goto out_complete;
824 }
825 } while (next_delay == 0);
826
827 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
828 goto out;
829
830 out_complete:
831 __ieee80211_scan_completed(&local->hw, aborted);
832 out:
833 mutex_unlock(&local->mtx);
834 }
835
836 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
837 struct cfg80211_scan_request *req)
838 {
839 int res;
840
841 mutex_lock(&sdata->local->mtx);
842 res = __ieee80211_start_scan(sdata, req);
843 mutex_unlock(&sdata->local->mtx);
844
845 return res;
846 }
847
848 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
849 const u8 *ssid, u8 ssid_len,
850 struct ieee80211_channel *chan,
851 enum nl80211_bss_scan_width scan_width)
852 {
853 struct ieee80211_local *local = sdata->local;
854 int ret = -EBUSY;
855 enum ieee80211_band band;
856
857 mutex_lock(&local->mtx);
858
859 /* busy scanning */
860 if (local->scan_req)
861 goto unlock;
862
863 /* fill internal scan request */
864 if (!chan) {
865 int i, max_n;
866 int n_ch = 0;
867
868 for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
869 if (!local->hw.wiphy->bands[band])
870 continue;
871
872 max_n = local->hw.wiphy->bands[band]->n_channels;
873 for (i = 0; i < max_n; i++) {
874 struct ieee80211_channel *tmp_ch =
875 &local->hw.wiphy->bands[band]->channels[i];
876
877 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
878 IEEE80211_CHAN_DISABLED))
879 continue;
880
881 local->int_scan_req->channels[n_ch] = tmp_ch;
882 n_ch++;
883 }
884 }
885
886 if (WARN_ON_ONCE(n_ch == 0))
887 goto unlock;
888
889 local->int_scan_req->n_channels = n_ch;
890 } else {
891 if (WARN_ON_ONCE(chan->flags & (IEEE80211_CHAN_NO_IR |
892 IEEE80211_CHAN_DISABLED)))
893 goto unlock;
894
895 local->int_scan_req->channels[0] = chan;
896 local->int_scan_req->n_channels = 1;
897 }
898
899 local->int_scan_req->ssids = &local->scan_ssid;
900 local->int_scan_req->n_ssids = 1;
901 local->int_scan_req->scan_width = scan_width;
902 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
903 local->int_scan_req->ssids[0].ssid_len = ssid_len;
904
905 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
906 unlock:
907 mutex_unlock(&local->mtx);
908 return ret;
909 }
910
911 /*
912 * Only call this function when a scan can't be queued -- under RTNL.
913 */
914 void ieee80211_scan_cancel(struct ieee80211_local *local)
915 {
916 /*
917 * We are canceling software scan, or deferred scan that was not
918 * yet really started (see __ieee80211_start_scan ).
919 *
920 * Regarding hardware scan:
921 * - we can not call __ieee80211_scan_completed() as when
922 * SCAN_HW_SCANNING bit is set this function change
923 * local->hw_scan_req to operate on 5G band, what race with
924 * driver which can use local->hw_scan_req
925 *
926 * - we can not cancel scan_work since driver can schedule it
927 * by ieee80211_scan_completed(..., true) to finish scan
928 *
929 * Hence we only call the cancel_hw_scan() callback, but the low-level
930 * driver is still responsible for calling ieee80211_scan_completed()
931 * after the scan was completed/aborted.
932 */
933
934 mutex_lock(&local->mtx);
935 if (!local->scan_req)
936 goto out;
937
938 /*
939 * We have a scan running and the driver already reported completion,
940 * but the worker hasn't run yet or is stuck on the mutex - mark it as
941 * cancelled.
942 */
943 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
944 test_bit(SCAN_COMPLETED, &local->scanning)) {
945 set_bit(SCAN_HW_CANCELLED, &local->scanning);
946 goto out;
947 }
948
949 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
950 /*
951 * Make sure that __ieee80211_scan_completed doesn't trigger a
952 * scan on another band.
953 */
954 set_bit(SCAN_HW_CANCELLED, &local->scanning);
955 if (local->ops->cancel_hw_scan)
956 drv_cancel_hw_scan(local,
957 rcu_dereference_protected(local->scan_sdata,
958 lockdep_is_held(&local->mtx)));
959 goto out;
960 }
961
962 /*
963 * If the work is currently running, it must be blocked on
964 * the mutex, but we'll set scan_sdata = NULL and it'll
965 * simply exit once it acquires the mutex.
966 */
967 cancel_delayed_work(&local->scan_work);
968 /* and clean up */
969 __ieee80211_scan_completed(&local->hw, true);
970 out:
971 mutex_unlock(&local->mtx);
972 }
973
974 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
975 struct cfg80211_sched_scan_request *req)
976 {
977 struct ieee80211_local *local = sdata->local;
978 struct ieee80211_sched_scan_ies sched_scan_ies = {};
979 struct cfg80211_chan_def chandef;
980 int ret, i, iebufsz;
981
982 iebufsz = 2 + IEEE80211_MAX_SSID_LEN +
983 local->scan_ies_len + req->ie_len;
984
985 lockdep_assert_held(&local->mtx);
986
987 if (!local->ops->sched_scan_start)
988 return -ENOTSUPP;
989
990 for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
991 if (!local->hw.wiphy->bands[i])
992 continue;
993
994 sched_scan_ies.ie[i] = kzalloc(iebufsz, GFP_KERNEL);
995 if (!sched_scan_ies.ie[i]) {
996 ret = -ENOMEM;
997 goto out_free;
998 }
999
1000 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1001
1002 sched_scan_ies.len[i] =
1003 ieee80211_build_preq_ies(local, sched_scan_ies.ie[i],
1004 iebufsz, req->ie, req->ie_len,
1005 i, (u32) -1, &chandef);
1006 }
1007
1008 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1009 if (ret == 0) {
1010 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1011 local->sched_scan_req = req;
1012 }
1013
1014 out_free:
1015 while (i > 0)
1016 kfree(sched_scan_ies.ie[--i]);
1017
1018 if (ret) {
1019 /* Clean in case of failure after HW restart or upon resume. */
1020 rcu_assign_pointer(local->sched_scan_sdata, NULL);
1021 local->sched_scan_req = NULL;
1022 }
1023
1024 return ret;
1025 }
1026
1027 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1028 struct cfg80211_sched_scan_request *req)
1029 {
1030 struct ieee80211_local *local = sdata->local;
1031 int ret;
1032
1033 mutex_lock(&local->mtx);
1034
1035 if (rcu_access_pointer(local->sched_scan_sdata)) {
1036 mutex_unlock(&local->mtx);
1037 return -EBUSY;
1038 }
1039
1040 ret = __ieee80211_request_sched_scan_start(sdata, req);
1041
1042 mutex_unlock(&local->mtx);
1043 return ret;
1044 }
1045
1046 int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata)
1047 {
1048 struct ieee80211_local *local = sdata->local;
1049 int ret = 0;
1050
1051 mutex_lock(&local->mtx);
1052
1053 if (!local->ops->sched_scan_stop) {
1054 ret = -ENOTSUPP;
1055 goto out;
1056 }
1057
1058 /* We don't want to restart sched scan anymore. */
1059 local->sched_scan_req = NULL;
1060
1061 if (rcu_access_pointer(local->sched_scan_sdata))
1062 drv_sched_scan_stop(local, sdata);
1063
1064 out:
1065 mutex_unlock(&local->mtx);
1066
1067 return ret;
1068 }
1069
1070 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1071 {
1072 struct ieee80211_local *local = hw_to_local(hw);
1073
1074 trace_api_sched_scan_results(local);
1075
1076 cfg80211_sched_scan_results(hw->wiphy);
1077 }
1078 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1079
1080 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1081 {
1082 struct ieee80211_local *local =
1083 container_of(work, struct ieee80211_local,
1084 sched_scan_stopped_work);
1085
1086 mutex_lock(&local->mtx);
1087
1088 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1089 mutex_unlock(&local->mtx);
1090 return;
1091 }
1092
1093 rcu_assign_pointer(local->sched_scan_sdata, NULL);
1094
1095 /* If sched scan was aborted by the driver. */
1096 local->sched_scan_req = NULL;
1097
1098 mutex_unlock(&local->mtx);
1099
1100 cfg80211_sched_scan_stopped(local->hw.wiphy);
1101 }
1102
1103 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1104 {
1105 struct ieee80211_local *local = hw_to_local(hw);
1106
1107 trace_api_sched_scan_stopped(local);
1108
1109 schedule_work(&local->sched_scan_stopped_work);
1110 }
1111 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
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