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mac80211: per interface idle notification
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0a51b27e 1/*
5484e237
JB
2 * Scanning implementation
3 *
0a51b27e
JB
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
0a51b27e 15#include <linux/if_arp.h>
078e1e60 16#include <linux/rtnetlink.h>
df13cce5
HS
17#include <linux/pm_qos_params.h>
18#include <net/sch_generic.h>
5a0e3ad6 19#include <linux/slab.h>
0a51b27e 20#include <net/mac80211.h>
0a51b27e
JB
21
22#include "ieee80211_i.h"
24487981 23#include "driver-ops.h"
5484e237 24#include "mesh.h"
0a51b27e
JB
25
26#define IEEE80211_PROBE_DELAY (HZ / 33)
27#define IEEE80211_CHANNEL_TIME (HZ / 33)
96f7e739 28#define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 8)
0a51b27e 29
c2b13452 30struct ieee80211_bss *
5484e237
JB
31ieee80211_rx_bss_get(struct ieee80211_local *local, u8 *bssid, int freq,
32 u8 *ssid, u8 ssid_len)
33{
0c1ad2ca
JB
34 struct cfg80211_bss *cbss;
35
36 cbss = cfg80211_get_bss(local->hw.wiphy,
37 ieee80211_get_channel(local->hw.wiphy, freq),
38 bssid, ssid, ssid_len, 0, 0);
39 if (!cbss)
40 return NULL;
41 return (void *)cbss->priv;
5484e237
JB
42}
43
00d3f14c 44static void ieee80211_rx_bss_free(struct cfg80211_bss *cbss)
5484e237 45{
0c1ad2ca 46 struct ieee80211_bss *bss = (void *)cbss->priv;
5484e237 47
5484e237
JB
48 kfree(bss_mesh_id(bss));
49 kfree(bss_mesh_cfg(bss));
5484e237
JB
50}
51
52void ieee80211_rx_bss_put(struct ieee80211_local *local,
c2b13452 53 struct ieee80211_bss *bss)
5484e237 54{
0c1ad2ca
JB
55 if (!bss)
56 return;
57 cfg80211_put_bss(container_of((void *)bss, struct cfg80211_bss, priv));
5484e237
JB
58}
59
ab13315a
KV
60static bool is_uapsd_supported(struct ieee802_11_elems *elems)
61{
62 u8 qos_info;
63
64 if (elems->wmm_info && elems->wmm_info_len == 7
65 && elems->wmm_info[5] == 1)
66 qos_info = elems->wmm_info[6];
67 else if (elems->wmm_param && elems->wmm_param_len == 24
68 && elems->wmm_param[5] == 1)
69 qos_info = elems->wmm_param[6];
70 else
71 /* no valid wmm information or parameter element found */
72 return false;
73
74 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
75}
76
c2b13452 77struct ieee80211_bss *
5484e237
JB
78ieee80211_bss_info_update(struct ieee80211_local *local,
79 struct ieee80211_rx_status *rx_status,
80 struct ieee80211_mgmt *mgmt,
81 size_t len,
82 struct ieee802_11_elems *elems,
2a519311
JB
83 struct ieee80211_channel *channel,
84 bool beacon)
5484e237 85{
0c1ad2ca 86 struct cfg80211_bss *cbss;
c2b13452 87 struct ieee80211_bss *bss;
f0b058b6 88 int clen, srlen;
2a519311
JB
89 s32 signal = 0;
90
77965c97 91 if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
2a519311 92 signal = rx_status->signal * 100;
77965c97 93 else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC)
2a519311 94 signal = (rx_status->signal * 100) / local->hw.max_signal;
2a519311 95
0c1ad2ca
JB
96 cbss = cfg80211_inform_bss_frame(local->hw.wiphy, channel,
97 mgmt, len, signal, GFP_ATOMIC);
5484e237 98
0c1ad2ca 99 if (!cbss)
00d3f14c
JB
100 return NULL;
101
0c1ad2ca
JB
102 cbss->free_priv = ieee80211_rx_bss_free;
103 bss = (void *)cbss->priv;
5484e237
JB
104
105 /* save the ERP value so that it is available at association time */
106 if (elems->erp_info && elems->erp_info_len >= 1) {
107 bss->erp_value = elems->erp_info[0];
108 bss->has_erp_value = 1;
109 }
110
5484e237
JB
111 if (elems->tim) {
112 struct ieee80211_tim_ie *tim_ie =
113 (struct ieee80211_tim_ie *)elems->tim;
114 bss->dtim_period = tim_ie->dtim_period;
115 }
116
e5b900d2
JB
117 /* If the beacon had no TIM IE, or it was invalid, use 1 */
118 if (beacon && !bss->dtim_period)
119 bss->dtim_period = 1;
120
f0b058b6
SG
121 /* replace old supported rates if we get new values */
122 srlen = 0;
5484e237 123 if (elems->supp_rates) {
f0b058b6 124 clen = IEEE80211_MAX_SUPP_RATES;
5484e237
JB
125 if (clen > elems->supp_rates_len)
126 clen = elems->supp_rates_len;
f0b058b6
SG
127 memcpy(bss->supp_rates, elems->supp_rates, clen);
128 srlen += clen;
5484e237
JB
129 }
130 if (elems->ext_supp_rates) {
f0b058b6 131 clen = IEEE80211_MAX_SUPP_RATES - srlen;
5484e237
JB
132 if (clen > elems->ext_supp_rates_len)
133 clen = elems->ext_supp_rates_len;
f0b058b6
SG
134 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates, clen);
135 srlen += clen;
5484e237 136 }
f0b058b6
SG
137 if (srlen)
138 bss->supp_rates_len = srlen;
5484e237 139
5484e237 140 bss->wmm_used = elems->wmm_param || elems->wmm_info;
ab13315a 141 bss->uapsd_supported = is_uapsd_supported(elems);
5484e237
JB
142
143 if (!beacon)
144 bss->last_probe_resp = jiffies;
145
5484e237
JB
146 return bss;
147}
0a51b27e 148
98c8fccf 149ieee80211_rx_result
f1d58c25 150ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
98c8fccf 151{
f1d58c25 152 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
98c8fccf 153 struct ieee80211_mgmt *mgmt;
c2b13452 154 struct ieee80211_bss *bss;
98c8fccf
JB
155 u8 *elements;
156 struct ieee80211_channel *channel;
157 size_t baselen;
158 int freq;
159 __le16 fc;
160 bool presp, beacon = false;
161 struct ieee802_11_elems elems;
162
163 if (skb->len < 2)
164 return RX_DROP_UNUSABLE;
165
166 mgmt = (struct ieee80211_mgmt *) skb->data;
167 fc = mgmt->frame_control;
168
169 if (ieee80211_is_ctl(fc))
170 return RX_CONTINUE;
171
172 if (skb->len < 24)
173 return RX_DROP_MONITOR;
174
175 presp = ieee80211_is_probe_resp(fc);
176 if (presp) {
177 /* ignore ProbeResp to foreign address */
47846c9b 178 if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN))
98c8fccf
JB
179 return RX_DROP_MONITOR;
180
181 presp = true;
182 elements = mgmt->u.probe_resp.variable;
183 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
184 } else {
185 beacon = ieee80211_is_beacon(fc);
186 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
187 elements = mgmt->u.beacon.variable;
188 }
189
190 if (!presp && !beacon)
191 return RX_CONTINUE;
192
193 if (baselen > skb->len)
194 return RX_DROP_MONITOR;
195
196 ieee802_11_parse_elems(elements, skb->len - baselen, &elems);
197
198 if (elems.ds_params && elems.ds_params_len == 1)
199 freq = ieee80211_channel_to_frequency(elems.ds_params[0]);
200 else
201 freq = rx_status->freq;
202
203 channel = ieee80211_get_channel(sdata->local->hw.wiphy, freq);
204
205 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
206 return RX_DROP_MONITOR;
207
208 bss = ieee80211_bss_info_update(sdata->local, rx_status,
209 mgmt, skb->len, &elems,
2a519311 210 channel, beacon);
d048e503
JM
211 if (bss)
212 ieee80211_rx_bss_put(sdata->local, bss);
98c8fccf
JB
213
214 dev_kfree_skb(skb);
215 return RX_QUEUED;
216}
217
4d36ec58
JB
218/* return false if no more work */
219static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
220{
221 struct cfg80211_scan_request *req = local->scan_req;
222 enum ieee80211_band band;
223 int i, ielen, n_chans;
224
225 do {
226 if (local->hw_scan_band == IEEE80211_NUM_BANDS)
227 return false;
228
229 band = local->hw_scan_band;
230 n_chans = 0;
231 for (i = 0; i < req->n_channels; i++) {
232 if (req->channels[i]->band == band) {
233 local->hw_scan_req->channels[n_chans] =
234 req->channels[i];
235 n_chans++;
236 }
237 }
238
239 local->hw_scan_band++;
240 } while (!n_chans);
241
242 local->hw_scan_req->n_channels = n_chans;
243
244 ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie,
245 req->ie, req->ie_len, band);
246 local->hw_scan_req->ie_len = ielen;
247
248 return true;
249}
250
2a519311 251void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
0a51b27e
JB
252{
253 struct ieee80211_local *local = hw_to_local(hw);
f3b85252 254 bool was_hw_scan;
0a51b27e 255
b5878a2d
JB
256 trace_api_scan_completed(local, aborted);
257
a1699b75 258 mutex_lock(&local->mtx);
5bc75728 259
6d3560d4
JB
260 /*
261 * It's ok to abort a not-yet-running scan (that
262 * we have one at all will be verified by checking
263 * local->scan_req next), but not to complete it
264 * successfully.
265 */
266 if (WARN_ON(!local->scanning && !aborted))
267 aborted = true;
5bc75728 268
f3b85252 269 if (WARN_ON(!local->scan_req)) {
a1699b75 270 mutex_unlock(&local->mtx);
f3b85252 271 return;
de95a54b
JB
272 }
273
4d36ec58
JB
274 was_hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
275 if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) {
276 ieee80211_queue_delayed_work(&local->hw,
277 &local->scan_work, 0);
a1699b75 278 mutex_unlock(&local->mtx);
4d36ec58
JB
279 return;
280 }
281
282 kfree(local->hw_scan_req);
283 local->hw_scan_req = NULL;
f3b85252 284
5ba63533 285 if (local->scan_req != local->int_scan_req)
2a519311
JB
286 cfg80211_scan_done(local->scan_req, aborted);
287 local->scan_req = NULL;
15db0b7f 288 local->scan_sdata = NULL;
2a519311 289
fbe9c429 290 local->scanning = 0;
58905ca5 291 local->scan_channel = NULL;
f3b85252
JB
292
293 /* we only have to protect scan_req and hw/sw scan */
a1699b75 294 mutex_unlock(&local->mtx);
f3b85252 295
e8975581 296 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
5cff20e6
JB
297 if (was_hw_scan)
298 goto done;
0a51b27e 299
3ac64bee 300 ieee80211_configure_filter(local);
0a51b27e 301
a0daa0e7
LR
302 drv_sw_scan_complete(local);
303
b203ffc3 304 ieee80211_offchannel_return(local, true);
0a51b27e
JB
305
306 done:
7da7cc1d 307 mutex_lock(&local->mtx);
5cff20e6 308 ieee80211_recalc_idle(local);
7da7cc1d 309 mutex_unlock(&local->mtx);
0a51b27e 310 ieee80211_mlme_notify_scan_completed(local);
46900298 311 ieee80211_ibss_notify_scan_completed(local);
472dbc45 312 ieee80211_mesh_notify_scan_completed(local);
81ac3462 313 ieee80211_queue_work(&local->hw, &local->work_work);
0a51b27e
JB
314}
315EXPORT_SYMBOL(ieee80211_scan_completed);
316
f3b85252
JB
317static int ieee80211_start_sw_scan(struct ieee80211_local *local)
318{
f3b85252
JB
319 /*
320 * Hardware/driver doesn't support hw_scan, so use software
321 * scanning instead. First send a nullfunc frame with power save
322 * bit on so that AP will buffer the frames for us while we are not
323 * listening, then send probe requests to each channel and wait for
324 * the responses. After all channels are scanned, tune back to the
325 * original channel and send a nullfunc frame with power save bit
326 * off to trigger the AP to send us all the buffered frames.
327 *
328 * Note that while local->sw_scanning is true everything else but
329 * nullfunc frames and probe requests will be dropped in
330 * ieee80211_tx_h_check_assoc().
331 */
24487981 332 drv_sw_scan_start(local);
f3b85252 333
b203ffc3 334 ieee80211_offchannel_stop_beaconing(local);
f3b85252 335
df13cce5 336 local->leave_oper_channel_time = 0;
977923b0 337 local->next_scan_state = SCAN_DECISION;
f3b85252
JB
338 local->scan_channel_idx = 0;
339
a80f7c0b
JB
340 drv_flush(local, false);
341
3ac64bee 342 ieee80211_configure_filter(local);
f3b85252 343
42935eca
LR
344 ieee80211_queue_delayed_work(&local->hw,
345 &local->scan_work,
346 IEEE80211_CHANNEL_TIME);
f3b85252
JB
347
348 return 0;
349}
350
351
352static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
353 struct cfg80211_scan_request *req)
354{
355 struct ieee80211_local *local = sdata->local;
f3b85252
JB
356 int rc;
357
358 if (local->scan_req)
359 return -EBUSY;
360
6e7e6213
JL
361 if (!list_empty(&local->work_list)) {
362 /* wait for the work to finish/time out */
c0ce77b8
JB
363 local->scan_req = req;
364 local->scan_sdata = sdata;
365 return 0;
366 }
367
f3b85252
JB
368 if (local->ops->hw_scan) {
369 u8 *ies;
f3b85252 370
4d36ec58
JB
371 local->hw_scan_req = kmalloc(
372 sizeof(*local->hw_scan_req) +
373 req->n_channels * sizeof(req->channels[0]) +
374 2 + IEEE80211_MAX_SSID_LEN + local->scan_ies_len +
375 req->ie_len, GFP_KERNEL);
376 if (!local->hw_scan_req)
f3b85252
JB
377 return -ENOMEM;
378
4d36ec58
JB
379 local->hw_scan_req->ssids = req->ssids;
380 local->hw_scan_req->n_ssids = req->n_ssids;
381 ies = (u8 *)local->hw_scan_req +
382 sizeof(*local->hw_scan_req) +
383 req->n_channels * sizeof(req->channels[0]);
384 local->hw_scan_req->ie = ies;
385
386 local->hw_scan_band = 0;
6e7e6213
JL
387
388 /*
389 * After allocating local->hw_scan_req, we must
390 * go through until ieee80211_prep_hw_scan(), so
391 * anything that might be changed here and leave
392 * this function early must not go after this
393 * allocation.
394 */
f3b85252
JB
395 }
396
397 local->scan_req = req;
398 local->scan_sdata = sdata;
399
f3b85252 400 if (local->ops->hw_scan)
fbe9c429 401 __set_bit(SCAN_HW_SCANNING, &local->scanning);
f3b85252 402 else
fbe9c429 403 __set_bit(SCAN_SW_SCANNING, &local->scanning);
6e7e6213 404
5cff20e6 405 ieee80211_recalc_idle(local);
f3b85252 406
4d36ec58
JB
407 if (local->ops->hw_scan) {
408 WARN_ON(!ieee80211_prep_hw_scan(local));
a060bbfe 409 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
4d36ec58 410 } else
f3b85252
JB
411 rc = ieee80211_start_sw_scan(local);
412
f3b85252 413 if (rc) {
4d36ec58
JB
414 kfree(local->hw_scan_req);
415 local->hw_scan_req = NULL;
fbe9c429 416 local->scanning = 0;
f3b85252 417
5cff20e6
JB
418 ieee80211_recalc_idle(local);
419
f3b85252
JB
420 local->scan_req = NULL;
421 local->scan_sdata = NULL;
422 }
423
424 return rc;
425}
426
df13cce5
HS
427static unsigned long
428ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
429{
430 /*
431 * TODO: channel switching also consumes quite some time,
432 * add that delay as well to get a better estimation
433 */
434 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN)
435 return IEEE80211_PASSIVE_CHANNEL_TIME;
436 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
437}
438
2fb3f028
HS
439static int ieee80211_scan_state_decision(struct ieee80211_local *local,
440 unsigned long *next_delay)
7d3be3cc 441{
142b9f50 442 bool associated = false;
df13cce5
HS
443 bool tx_empty = true;
444 bool bad_latency;
445 bool listen_int_exceeded;
446 unsigned long min_beacon_int = 0;
142b9f50 447 struct ieee80211_sub_if_data *sdata;
df13cce5 448 struct ieee80211_channel *next_chan;
142b9f50
HS
449
450 /* if no more bands/channels left, complete scan and advance to the idle state */
7d3be3cc
HS
451 if (local->scan_channel_idx >= local->scan_req->n_channels) {
452 ieee80211_scan_completed(&local->hw, false);
453 return 1;
454 }
2fb3f028 455
df13cce5
HS
456 /*
457 * check if at least one STA interface is associated,
458 * check if at least one STA interface has pending tx frames
459 * and grab the lowest used beacon interval
460 */
142b9f50
HS
461 mutex_lock(&local->iflist_mtx);
462 list_for_each_entry(sdata, &local->interfaces, list) {
9607e6b6 463 if (!ieee80211_sdata_running(sdata))
142b9f50
HS
464 continue;
465
466 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
467 if (sdata->u.mgd.associated) {
468 associated = true;
df13cce5
HS
469
470 if (sdata->vif.bss_conf.beacon_int <
471 min_beacon_int || min_beacon_int == 0)
472 min_beacon_int =
473 sdata->vif.bss_conf.beacon_int;
474
475 if (!qdisc_all_tx_empty(sdata->dev)) {
476 tx_empty = false;
477 break;
478 }
142b9f50
HS
479 }
480 }
481 }
482 mutex_unlock(&local->iflist_mtx);
483
484 if (local->scan_channel) {
485 /*
486 * we're currently scanning a different channel, let's
df13cce5
HS
487 * see if we can scan another channel without interfering
488 * with the current traffic situation.
489 *
490 * Since we don't know if the AP has pending frames for us
491 * we can only check for our tx queues and use the current
492 * pm_qos requirements for rx. Hence, if no tx traffic occurs
493 * at all we will scan as many channels in a row as the pm_qos
494 * latency allows us to. Additionally we also check for the
495 * currently negotiated listen interval to prevent losing
496 * frames unnecessarily.
497 *
498 * Otherwise switch back to the operating channel.
142b9f50 499 */
df13cce5
HS
500 next_chan = local->scan_req->channels[local->scan_channel_idx];
501
502 bad_latency = time_after(jiffies +
503 ieee80211_scan_get_channel_time(next_chan),
504 local->leave_oper_channel_time +
f8965467 505 usecs_to_jiffies(pm_qos_request(PM_QOS_NETWORK_LATENCY)));
df13cce5
HS
506
507 listen_int_exceeded = time_after(jiffies +
508 ieee80211_scan_get_channel_time(next_chan),
509 local->leave_oper_channel_time +
510 usecs_to_jiffies(min_beacon_int * 1024) *
511 local->hw.conf.listen_interval);
512
513 if (associated && ( !tx_empty || bad_latency ||
514 listen_int_exceeded))
977923b0 515 local->next_scan_state = SCAN_ENTER_OPER_CHANNEL;
142b9f50 516 else
977923b0 517 local->next_scan_state = SCAN_SET_CHANNEL;
142b9f50
HS
518 } else {
519 /*
520 * we're on the operating channel currently, let's
521 * leave that channel now to scan another one
522 */
977923b0 523 local->next_scan_state = SCAN_LEAVE_OPER_CHANNEL;
142b9f50
HS
524 }
525
2fb3f028 526 *next_delay = 0;
2fb3f028
HS
527 return 0;
528}
529
142b9f50
HS
530static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local,
531 unsigned long *next_delay)
532{
b203ffc3 533 ieee80211_offchannel_stop_station(local);
142b9f50
HS
534
535 __set_bit(SCAN_OFF_CHANNEL, &local->scanning);
536
a80f7c0b
JB
537 /*
538 * What if the nullfunc frames didn't arrive?
539 */
540 drv_flush(local, false);
541 if (local->ops->flush)
542 *next_delay = 0;
543 else
544 *next_delay = HZ / 10;
545
df13cce5
HS
546 /* remember when we left the operating channel */
547 local->leave_oper_channel_time = jiffies;
548
142b9f50 549 /* advance to the next channel to be scanned */
977923b0 550 local->next_scan_state = SCAN_SET_CHANNEL;
142b9f50
HS
551}
552
553static void ieee80211_scan_state_enter_oper_channel(struct ieee80211_local *local,
554 unsigned long *next_delay)
555{
142b9f50
HS
556 /* switch back to the operating channel */
557 local->scan_channel = NULL;
558 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
559
560 /*
b203ffc3
JM
561 * Only re-enable station mode interface now; beaconing will be
562 * re-enabled once the full scan has been completed.
142b9f50 563 */
b203ffc3 564 ieee80211_offchannel_return(local, false);
142b9f50
HS
565
566 __clear_bit(SCAN_OFF_CHANNEL, &local->scanning);
567
568 *next_delay = HZ / 5;
977923b0 569 local->next_scan_state = SCAN_DECISION;
142b9f50
HS
570}
571
2fb3f028
HS
572static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
573 unsigned long *next_delay)
574{
575 int skip;
576 struct ieee80211_channel *chan;
2fb3f028 577
7d3be3cc
HS
578 skip = 0;
579 chan = local->scan_req->channels[local->scan_channel_idx];
580
584991dc
JB
581 local->scan_channel = chan;
582 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
7d3be3cc
HS
583 skip = 1;
584
7d3be3cc
HS
585 /* advance state machine to next channel/band */
586 local->scan_channel_idx++;
587
0ee9c13c
HS
588 if (skip) {
589 /* if we skip this channel return to the decision state */
590 local->next_scan_state = SCAN_DECISION;
2fb3f028 591 return;
0ee9c13c 592 }
7d3be3cc
HS
593
594 /*
595 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
596 * (which unfortunately doesn't say _why_ step a) is done,
597 * but it waits for the probe delay or until a frame is
598 * received - and the received frame would update the NAV).
599 * For now, we do not support waiting until a frame is
600 * received.
601 *
602 * In any case, it is not necessary for a passive scan.
603 */
604 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN ||
605 !local->scan_req->n_ssids) {
606 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
977923b0 607 local->next_scan_state = SCAN_DECISION;
2fb3f028 608 return;
7d3be3cc
HS
609 }
610
2fb3f028 611 /* active scan, send probes */
7d3be3cc 612 *next_delay = IEEE80211_PROBE_DELAY;
977923b0 613 local->next_scan_state = SCAN_SEND_PROBE;
7d3be3cc
HS
614}
615
616static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
617 unsigned long *next_delay)
618{
619 int i;
620 struct ieee80211_sub_if_data *sdata = local->scan_sdata;
621
622 for (i = 0; i < local->scan_req->n_ssids; i++)
623 ieee80211_send_probe_req(
624 sdata, NULL,
625 local->scan_req->ssids[i].ssid,
626 local->scan_req->ssids[i].ssid_len,
627 local->scan_req->ie, local->scan_req->ie_len);
628
629 /*
630 * After sending probe requests, wait for probe responses
631 * on the channel.
632 */
633 *next_delay = IEEE80211_CHANNEL_TIME;
977923b0 634 local->next_scan_state = SCAN_DECISION;
7d3be3cc
HS
635}
636
c2b13452 637void ieee80211_scan_work(struct work_struct *work)
0a51b27e
JB
638{
639 struct ieee80211_local *local =
640 container_of(work, struct ieee80211_local, scan_work.work);
641 struct ieee80211_sub_if_data *sdata = local->scan_sdata;
0a51b27e
JB
642 unsigned long next_delay = 0;
643
a1699b75 644 mutex_lock(&local->mtx);
f3b85252 645 if (!sdata || !local->scan_req) {
a1699b75 646 mutex_unlock(&local->mtx);
f3b85252
JB
647 return;
648 }
649
4d36ec58 650 if (local->hw_scan_req) {
a060bbfe 651 int rc = drv_hw_scan(local, sdata, local->hw_scan_req);
a1699b75 652 mutex_unlock(&local->mtx);
4d36ec58
JB
653 if (rc)
654 ieee80211_scan_completed(&local->hw, true);
655 return;
656 }
657
fbe9c429 658 if (local->scan_req && !local->scanning) {
f3b85252
JB
659 struct cfg80211_scan_request *req = local->scan_req;
660 int rc;
661
662 local->scan_req = NULL;
15db0b7f 663 local->scan_sdata = NULL;
f3b85252
JB
664
665 rc = __ieee80211_start_scan(sdata, req);
a1699b75 666 mutex_unlock(&local->mtx);
f3b85252
JB
667
668 if (rc)
669 ieee80211_scan_completed(&local->hw, true);
670 return;
671 }
672
a1699b75 673 mutex_unlock(&local->mtx);
f3b85252 674
5bc75728
JB
675 /*
676 * Avoid re-scheduling when the sdata is going away.
677 */
9607e6b6 678 if (!ieee80211_sdata_running(sdata)) {
f3b85252 679 ieee80211_scan_completed(&local->hw, true);
0a51b27e 680 return;
f3b85252 681 }
0a51b27e 682
f502d09b
HS
683 /*
684 * as long as no delay is required advance immediately
685 * without scheduling a new work
686 */
687 do {
977923b0 688 switch (local->next_scan_state) {
2fb3f028
HS
689 case SCAN_DECISION:
690 if (ieee80211_scan_state_decision(local, &next_delay))
f502d09b
HS
691 return;
692 break;
2fb3f028
HS
693 case SCAN_SET_CHANNEL:
694 ieee80211_scan_state_set_channel(local, &next_delay);
695 break;
f502d09b
HS
696 case SCAN_SEND_PROBE:
697 ieee80211_scan_state_send_probe(local, &next_delay);
698 break;
142b9f50
HS
699 case SCAN_LEAVE_OPER_CHANNEL:
700 ieee80211_scan_state_leave_oper_channel(local, &next_delay);
701 break;
702 case SCAN_ENTER_OPER_CHANNEL:
703 ieee80211_scan_state_enter_oper_channel(local, &next_delay);
704 break;
f502d09b
HS
705 }
706 } while (next_delay == 0);
0a51b27e 707
42935eca 708 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
0a51b27e
JB
709}
710
f3b85252
JB
711int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
712 struct cfg80211_scan_request *req)
0a51b27e 713{
f3b85252 714 int res;
de95a54b 715
a1699b75 716 mutex_lock(&sdata->local->mtx);
f3b85252 717 res = __ieee80211_start_scan(sdata, req);
a1699b75 718 mutex_unlock(&sdata->local->mtx);
0a51b27e 719
f3b85252 720 return res;
0a51b27e
JB
721}
722
f3b85252 723int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata,
be4a4b6a
JB
724 const u8 *ssid, u8 ssid_len,
725 struct ieee80211_channel *chan)
0a51b27e 726{
0a51b27e 727 struct ieee80211_local *local = sdata->local;
f3b85252 728 int ret = -EBUSY;
fb63bc41 729 enum ieee80211_band band;
2a519311 730
a1699b75 731 mutex_lock(&local->mtx);
0a51b27e 732
f3b85252
JB
733 /* busy scanning */
734 if (local->scan_req)
735 goto unlock;
9116dd01 736
be4a4b6a
JB
737 /* fill internal scan request */
738 if (!chan) {
739 int i, nchan = 0;
740
741 for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
742 if (!local->hw.wiphy->bands[band])
743 continue;
744 for (i = 0;
745 i < local->hw.wiphy->bands[band]->n_channels;
746 i++) {
747 local->int_scan_req->channels[nchan] =
748 &local->hw.wiphy->bands[band]->channels[i];
749 nchan++;
750 }
751 }
752
753 local->int_scan_req->n_channels = nchan;
754 } else {
755 local->int_scan_req->channels[0] = chan;
756 local->int_scan_req->n_channels = 1;
757 }
758
759 local->int_scan_req->ssids = &local->scan_ssid;
760 local->int_scan_req->n_ssids = 1;
5ba63533
JB
761 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
762 local->int_scan_req->ssids[0].ssid_len = ssid_len;
9116dd01 763
5ba63533 764 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
f3b85252 765 unlock:
a1699b75 766 mutex_unlock(&local->mtx);
f3b85252 767 return ret;
0a51b27e 768}
5bb644a0
JB
769
770void ieee80211_scan_cancel(struct ieee80211_local *local)
771{
15db0b7f 772 bool abortscan;
5bb644a0
JB
773
774 cancel_delayed_work_sync(&local->scan_work);
775
776 /*
777 * Only call this function when a scan can't be
778 * queued -- mostly at suspend under RTNL.
779 */
a1699b75 780 mutex_lock(&local->mtx);
15db0b7f
JB
781 abortscan = test_bit(SCAN_SW_SCANNING, &local->scanning) ||
782 (!local->scanning && local->scan_req);
a1699b75 783 mutex_unlock(&local->mtx);
5bb644a0 784
15db0b7f 785 if (abortscan)
5bb644a0
JB
786 ieee80211_scan_completed(&local->hw, true);
787}