2 * Scanning implementation
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
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.
16 #include <linux/if_arp.h>
17 #include <linux/etherdevice.h>
18 #include <linux/rtnetlink.h>
19 #include <linux/pm_qos.h>
20 #include <net/sch_generic.h>
21 #include <linux/slab.h>
22 #include <linux/export.h>
23 #include <net/mac80211.h>
25 #include "ieee80211_i.h"
26 #include "driver-ops.h"
29 #define IEEE80211_PROBE_DELAY (HZ / 33)
30 #define IEEE80211_CHANNEL_TIME (HZ / 33)
31 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
33 void ieee80211_rx_bss_put(struct ieee80211_local
*local
,
34 struct ieee80211_bss
*bss
)
38 cfg80211_put_bss(local
->hw
.wiphy
,
39 container_of((void *)bss
, struct cfg80211_bss
, priv
));
42 static bool is_uapsd_supported(struct ieee802_11_elems
*elems
)
46 if (elems
->wmm_info
&& elems
->wmm_info_len
== 7
47 && elems
->wmm_info
[5] == 1)
48 qos_info
= elems
->wmm_info
[6];
49 else if (elems
->wmm_param
&& elems
->wmm_param_len
== 24
50 && elems
->wmm_param
[5] == 1)
51 qos_info
= elems
->wmm_param
[6];
53 /* no valid wmm information or parameter element found */
56 return qos_info
& IEEE80211_WMM_IE_AP_QOSINFO_UAPSD
;
59 struct ieee80211_bss
*
60 ieee80211_bss_info_update(struct ieee80211_local
*local
,
61 struct ieee80211_rx_status
*rx_status
,
62 struct ieee80211_mgmt
*mgmt
, size_t len
,
63 struct ieee802_11_elems
*elems
,
64 struct ieee80211_channel
*channel
)
66 bool beacon
= ieee80211_is_beacon(mgmt
->frame_control
);
67 struct cfg80211_bss
*cbss
;
68 struct ieee80211_bss
*bss
;
70 enum nl80211_bss_scan_width scan_width
;
74 if (ieee80211_hw_check(&local
->hw
, SIGNAL_DBM
))
75 signal
= rx_status
->signal
* 100;
76 else if (ieee80211_hw_check(&local
->hw
, SIGNAL_UNSPEC
))
77 signal
= (rx_status
->signal
* 100) / local
->hw
.max_signal
;
79 scan_width
= NL80211_BSS_CHAN_WIDTH_20
;
80 if (rx_status
->flag
& RX_FLAG_5MHZ
)
81 scan_width
= NL80211_BSS_CHAN_WIDTH_5
;
82 if (rx_status
->flag
& RX_FLAG_10MHZ
)
83 scan_width
= NL80211_BSS_CHAN_WIDTH_10
;
85 cbss
= cfg80211_inform_bss_width_frame(local
->hw
.wiphy
, channel
,
86 scan_width
, mgmt
, len
, signal
,
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
;
94 rx_status
->flag
|= RX_FLAG_NO_SIGNAL_VAL
;
96 bss
= (void *)cbss
->priv
;
99 bss
->device_ts_beacon
= rx_status
->device_timestamp
;
101 bss
->device_ts_presp
= rx_status
->device_timestamp
;
103 if (elems
->parse_error
) {
105 bss
->corrupt_data
|= IEEE80211_BSS_CORRUPT_BEACON
;
107 bss
->corrupt_data
|= IEEE80211_BSS_CORRUPT_PROBE_RESP
;
110 bss
->corrupt_data
&= ~IEEE80211_BSS_CORRUPT_BEACON
;
112 bss
->corrupt_data
&= ~IEEE80211_BSS_CORRUPT_PROBE_RESP
;
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
;
124 /* replace old supported rates if we get new values */
125 if (!elems
->parse_error
||
126 !(bss
->valid_data
& IEEE80211_BSS_VALID_RATES
)) {
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
);
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
,
144 bss
->supp_rates_len
= srlen
;
145 if (!elems
->parse_error
)
146 bss
->valid_data
|= IEEE80211_BSS_VALID_RATES
;
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
;
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
))
164 &sband
->bitrates
[rx_status
->rate_idx
];
170 void ieee80211_scan_rx(struct ieee80211_local
*local
, struct sk_buff
*skb
)
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
;
177 struct ieee80211_channel
*channel
;
179 struct ieee802_11_elems elems
;
182 (!ieee80211_is_probe_resp(mgmt
->frame_control
) &&
183 !ieee80211_is_beacon(mgmt
->frame_control
)))
186 sdata1
= rcu_dereference(local
->scan_sdata
);
187 sdata2
= rcu_dereference(local
->sched_scan_sdata
);
189 if (likely(!sdata1
&& !sdata2
))
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
;
196 scan_req
= rcu_dereference(local
->scan_req
);
197 sched_scan_req
= rcu_dereference(local
->sched_scan_req
);
199 /* ignore ProbeResp to foreign address unless scanning
200 * with randomised address
203 (ether_addr_equal(mgmt
->da
, sdata1
->vif
.addr
) ||
204 scan_req
->flags
& NL80211_SCAN_FLAG_RANDOM_ADDR
)) &&
206 (ether_addr_equal(mgmt
->da
, sdata2
->vif
.addr
) ||
207 sched_scan_req
->flags
& NL80211_SCAN_FLAG_RANDOM_ADDR
)))
210 elements
= mgmt
->u
.probe_resp
.variable
;
211 baselen
= offsetof(struct ieee80211_mgmt
, u
.probe_resp
.variable
);
213 baselen
= offsetof(struct ieee80211_mgmt
, u
.beacon
.variable
);
214 elements
= mgmt
->u
.beacon
.variable
;
217 if (baselen
> skb
->len
)
220 ieee802_11_parse_elems(elements
, skb
->len
- baselen
, false, &elems
);
222 channel
= ieee80211_get_channel(local
->hw
.wiphy
, rx_status
->freq
);
224 if (!channel
|| channel
->flags
& IEEE80211_CHAN_DISABLED
)
227 bss
= ieee80211_bss_info_update(local
, rx_status
,
228 mgmt
, skb
->len
, &elems
,
231 ieee80211_rx_bss_put(local
, bss
);
235 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def
*chandef
,
236 enum nl80211_bss_scan_width scan_width
)
238 memset(chandef
, 0, sizeof(*chandef
));
239 switch (scan_width
) {
240 case NL80211_BSS_CHAN_WIDTH_5
:
241 chandef
->width
= NL80211_CHAN_WIDTH_5
;
243 case NL80211_BSS_CHAN_WIDTH_10
:
244 chandef
->width
= NL80211_CHAN_WIDTH_10
;
247 chandef
->width
= NL80211_CHAN_WIDTH_20_NOHT
;
252 /* return false if no more work */
253 static bool ieee80211_prep_hw_scan(struct ieee80211_local
*local
)
255 struct cfg80211_scan_request
*req
;
256 struct cfg80211_chan_def chandef
;
258 int i
, ielen
, n_chans
;
260 req
= rcu_dereference_protected(local
->scan_req
,
261 lockdep_is_held(&local
->mtx
));
263 if (test_bit(SCAN_HW_CANCELLED
, &local
->scanning
))
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
);
272 n_chans
= req
->n_channels
;
275 if (local
->hw_scan_band
== IEEE80211_NUM_BANDS
)
280 for (i
= 0; i
< req
->n_channels
; i
++) {
281 if (req
->channels
[i
]->band
!=
284 local
->hw_scan_req
->req
.channels
[n_chans
] =
287 bands_used
|= BIT(req
->channels
[i
]->band
);
290 local
->hw_scan_band
++;
294 local
->hw_scan_req
->req
.n_channels
= n_chans
;
295 ieee80211_prepare_scan_chandef(&chandef
, req
->scan_width
);
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
,
312 static void __ieee80211_scan_completed(struct ieee80211_hw
*hw
, bool aborted
)
314 struct ieee80211_local
*local
= hw_to_local(hw
);
315 bool hw_scan
= local
->ops
->hw_scan
;
316 bool was_scanning
= local
->scanning
;
317 struct cfg80211_scan_request
*scan_req
;
318 struct ieee80211_sub_if_data
*scan_sdata
;
320 lockdep_assert_held(&local
->mtx
);
323 * It's ok to abort a not-yet-running scan (that
324 * we have one at all will be verified by checking
325 * local->scan_req next), but not to complete it
328 if (WARN_ON(!local
->scanning
&& !aborted
))
331 if (WARN_ON(!local
->scan_req
))
334 if (hw_scan
&& !aborted
&&
335 !ieee80211_hw_check(&local
->hw
, SINGLE_SCAN_ON_ALL_BANDS
) &&
336 ieee80211_prep_hw_scan(local
)) {
339 rc
= drv_hw_scan(local
,
340 rcu_dereference_protected(local
->scan_sdata
,
341 lockdep_is_held(&local
->mtx
)),
348 kfree(local
->hw_scan_req
);
349 local
->hw_scan_req
= NULL
;
351 scan_req
= rcu_dereference_protected(local
->scan_req
,
352 lockdep_is_held(&local
->mtx
));
354 if (scan_req
!= local
->int_scan_req
)
355 cfg80211_scan_done(scan_req
, aborted
);
356 RCU_INIT_POINTER(local
->scan_req
, NULL
);
358 scan_sdata
= rcu_dereference_protected(local
->scan_sdata
,
359 lockdep_is_held(&local
->mtx
));
360 RCU_INIT_POINTER(local
->scan_sdata
, NULL
);
363 local
->scan_chandef
.chan
= NULL
;
365 /* Set power back to normal operating levels. */
366 ieee80211_hw_config(local
, 0);
369 ieee80211_configure_filter(local
);
370 drv_sw_scan_complete(local
, scan_sdata
);
371 ieee80211_offchannel_return(local
);
374 ieee80211_recalc_idle(local
);
376 ieee80211_mlme_notify_scan_completed(local
);
377 ieee80211_ibss_notify_scan_completed(local
);
378 ieee80211_mesh_notify_scan_completed(local
);
380 ieee80211_start_next_roc(local
);
383 void ieee80211_scan_completed(struct ieee80211_hw
*hw
, bool aborted
)
385 struct ieee80211_local
*local
= hw_to_local(hw
);
387 trace_api_scan_completed(local
, aborted
);
389 set_bit(SCAN_COMPLETED
, &local
->scanning
);
391 set_bit(SCAN_ABORTED
, &local
->scanning
);
392 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
, 0);
394 EXPORT_SYMBOL(ieee80211_scan_completed
);
396 static int ieee80211_start_sw_scan(struct ieee80211_local
*local
,
397 struct ieee80211_sub_if_data
*sdata
)
399 /* Software scan is not supported in multi-channel cases */
400 if (local
->use_chanctx
)
404 * Hardware/driver doesn't support hw_scan, so use software
405 * scanning instead. First send a nullfunc frame with power save
406 * bit on so that AP will buffer the frames for us while we are not
407 * listening, then send probe requests to each channel and wait for
408 * the responses. After all channels are scanned, tune back to the
409 * original channel and send a nullfunc frame with power save bit
410 * off to trigger the AP to send us all the buffered frames.
412 * Note that while local->sw_scanning is true everything else but
413 * nullfunc frames and probe requests will be dropped in
414 * ieee80211_tx_h_check_assoc().
416 drv_sw_scan_start(local
, sdata
, local
->scan_addr
);
418 local
->leave_oper_channel_time
= jiffies
;
419 local
->next_scan_state
= SCAN_DECISION
;
420 local
->scan_channel_idx
= 0;
422 ieee80211_offchannel_stop_vifs(local
);
424 /* ensure nullfunc is transmitted before leaving operating channel */
425 ieee80211_flush_queues(local
, NULL
, false);
427 ieee80211_configure_filter(local
);
429 /* We need to set power level at maximum rate for scanning. */
430 ieee80211_hw_config(local
, 0);
432 ieee80211_queue_delayed_work(&local
->hw
,
433 &local
->scan_work
, 0);
438 static bool ieee80211_can_scan(struct ieee80211_local
*local
,
439 struct ieee80211_sub_if_data
*sdata
)
441 if (ieee80211_is_radar_required(local
))
444 if (!list_empty(&local
->roc_list
))
447 if (sdata
->vif
.type
== NL80211_IFTYPE_STATION
&&
448 sdata
->u
.mgd
.flags
& IEEE80211_STA_CONNECTION_POLL
)
454 void ieee80211_run_deferred_scan(struct ieee80211_local
*local
)
456 lockdep_assert_held(&local
->mtx
);
458 if (!local
->scan_req
|| local
->scanning
)
461 if (!ieee80211_can_scan(local
,
462 rcu_dereference_protected(
464 lockdep_is_held(&local
->mtx
))))
467 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
,
468 round_jiffies_relative(0));
471 static void ieee80211_scan_state_send_probe(struct ieee80211_local
*local
,
472 unsigned long *next_delay
)
475 struct ieee80211_sub_if_data
*sdata
;
476 struct cfg80211_scan_request
*scan_req
;
477 enum ieee80211_band band
= local
->hw
.conf
.chandef
.chan
->band
;
480 scan_req
= rcu_dereference_protected(local
->scan_req
,
481 lockdep_is_held(&local
->mtx
));
483 tx_flags
= IEEE80211_TX_INTFL_OFFCHAN_TX_OK
;
484 if (scan_req
->no_cck
)
485 tx_flags
|= IEEE80211_TX_CTL_NO_CCK_RATE
;
487 sdata
= rcu_dereference_protected(local
->scan_sdata
,
488 lockdep_is_held(&local
->mtx
));
490 for (i
= 0; i
< scan_req
->n_ssids
; i
++)
491 ieee80211_send_probe_req(
492 sdata
, local
->scan_addr
, NULL
,
493 scan_req
->ssids
[i
].ssid
, scan_req
->ssids
[i
].ssid_len
,
494 scan_req
->ie
, scan_req
->ie_len
,
495 scan_req
->rates
[band
], false,
496 tx_flags
, local
->hw
.conf
.chandef
.chan
, true);
499 * After sending probe requests, wait for probe responses
502 *next_delay
= IEEE80211_CHANNEL_TIME
;
503 local
->next_scan_state
= SCAN_DECISION
;
506 static int __ieee80211_start_scan(struct ieee80211_sub_if_data
*sdata
,
507 struct cfg80211_scan_request
*req
)
509 struct ieee80211_local
*local
= sdata
->local
;
512 lockdep_assert_held(&local
->mtx
);
514 if (local
->scan_req
|| ieee80211_is_radar_required(local
))
517 if (!ieee80211_can_scan(local
, sdata
)) {
518 /* wait for the work to finish/time out */
519 rcu_assign_pointer(local
->scan_req
, req
);
520 rcu_assign_pointer(local
->scan_sdata
, sdata
);
524 if (local
->ops
->hw_scan
) {
527 local
->hw_scan_ies_bufsize
= local
->scan_ies_len
+ req
->ie_len
;
529 if (ieee80211_hw_check(&local
->hw
, SINGLE_SCAN_ON_ALL_BANDS
)) {
531 u8 bands_counted
= 0;
533 for (i
= 0; i
< req
->n_channels
; i
++) {
534 if (bands_counted
& BIT(req
->channels
[i
]->band
))
536 bands_counted
|= BIT(req
->channels
[i
]->band
);
540 local
->hw_scan_ies_bufsize
*= n_bands
;
543 local
->hw_scan_req
= kmalloc(
544 sizeof(*local
->hw_scan_req
) +
545 req
->n_channels
* sizeof(req
->channels
[0]) +
546 local
->hw_scan_ies_bufsize
, GFP_KERNEL
);
547 if (!local
->hw_scan_req
)
550 local
->hw_scan_req
->req
.ssids
= req
->ssids
;
551 local
->hw_scan_req
->req
.n_ssids
= req
->n_ssids
;
552 ies
= (u8
*)local
->hw_scan_req
+
553 sizeof(*local
->hw_scan_req
) +
554 req
->n_channels
* sizeof(req
->channels
[0]);
555 local
->hw_scan_req
->req
.ie
= ies
;
556 local
->hw_scan_req
->req
.flags
= req
->flags
;
558 local
->hw_scan_band
= 0;
561 * After allocating local->hw_scan_req, we must
562 * go through until ieee80211_prep_hw_scan(), so
563 * anything that might be changed here and leave
564 * this function early must not go after this
569 rcu_assign_pointer(local
->scan_req
, req
);
570 rcu_assign_pointer(local
->scan_sdata
, sdata
);
572 if (req
->flags
& NL80211_SCAN_FLAG_RANDOM_ADDR
)
573 get_random_mask_addr(local
->scan_addr
,
577 memcpy(local
->scan_addr
, sdata
->vif
.addr
, ETH_ALEN
);
579 if (local
->ops
->hw_scan
) {
580 __set_bit(SCAN_HW_SCANNING
, &local
->scanning
);
581 } else if ((req
->n_channels
== 1) &&
582 (req
->channels
[0] == local
->_oper_chandef
.chan
)) {
584 * If we are scanning only on the operating channel
585 * then we do not need to stop normal activities
587 unsigned long next_delay
;
589 __set_bit(SCAN_ONCHANNEL_SCANNING
, &local
->scanning
);
591 ieee80211_recalc_idle(local
);
593 /* Notify driver scan is starting, keep order of operations
594 * same as normal software scan, in case that matters. */
595 drv_sw_scan_start(local
, sdata
, local
->scan_addr
);
597 ieee80211_configure_filter(local
); /* accept probe-responses */
599 /* We need to ensure power level is at max for scanning. */
600 ieee80211_hw_config(local
, 0);
602 if ((req
->channels
[0]->flags
&
603 IEEE80211_CHAN_NO_IR
) ||
605 next_delay
= IEEE80211_PASSIVE_CHANNEL_TIME
;
607 ieee80211_scan_state_send_probe(local
, &next_delay
);
608 next_delay
= IEEE80211_CHANNEL_TIME
;
611 /* Now, just wait a bit and we are all done! */
612 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
,
616 /* Do normal software scan */
617 __set_bit(SCAN_SW_SCANNING
, &local
->scanning
);
620 ieee80211_recalc_idle(local
);
622 if (local
->ops
->hw_scan
) {
623 WARN_ON(!ieee80211_prep_hw_scan(local
));
624 rc
= drv_hw_scan(local
, sdata
, local
->hw_scan_req
);
626 rc
= ieee80211_start_sw_scan(local
, sdata
);
630 kfree(local
->hw_scan_req
);
631 local
->hw_scan_req
= NULL
;
634 ieee80211_recalc_idle(local
);
636 local
->scan_req
= NULL
;
637 RCU_INIT_POINTER(local
->scan_sdata
, NULL
);
644 ieee80211_scan_get_channel_time(struct ieee80211_channel
*chan
)
647 * TODO: channel switching also consumes quite some time,
648 * add that delay as well to get a better estimation
650 if (chan
->flags
& IEEE80211_CHAN_NO_IR
)
651 return IEEE80211_PASSIVE_CHANNEL_TIME
;
652 return IEEE80211_PROBE_DELAY
+ IEEE80211_CHANNEL_TIME
;
655 static void ieee80211_scan_state_decision(struct ieee80211_local
*local
,
656 unsigned long *next_delay
)
658 bool associated
= false;
659 bool tx_empty
= true;
661 struct ieee80211_sub_if_data
*sdata
;
662 struct ieee80211_channel
*next_chan
;
663 enum mac80211_scan_state next_scan_state
;
664 struct cfg80211_scan_request
*scan_req
;
667 * check if at least one STA interface is associated,
668 * check if at least one STA interface has pending tx frames
669 * and grab the lowest used beacon interval
671 mutex_lock(&local
->iflist_mtx
);
672 list_for_each_entry(sdata
, &local
->interfaces
, list
) {
673 if (!ieee80211_sdata_running(sdata
))
676 if (sdata
->vif
.type
== NL80211_IFTYPE_STATION
) {
677 if (sdata
->u
.mgd
.associated
) {
680 if (!qdisc_all_tx_empty(sdata
->dev
)) {
687 mutex_unlock(&local
->iflist_mtx
);
689 scan_req
= rcu_dereference_protected(local
->scan_req
,
690 lockdep_is_held(&local
->mtx
));
692 next_chan
= scan_req
->channels
[local
->scan_channel_idx
];
695 * we're currently scanning a different channel, let's
696 * see if we can scan another channel without interfering
697 * with the current traffic situation.
699 * Keep good latency, do not stay off-channel more than 125 ms.
702 bad_latency
= time_after(jiffies
+
703 ieee80211_scan_get_channel_time(next_chan
),
704 local
->leave_oper_channel_time
+ HZ
/ 8);
706 if (associated
&& !tx_empty
) {
707 if (scan_req
->flags
& NL80211_SCAN_FLAG_LOW_PRIORITY
)
708 next_scan_state
= SCAN_ABORT
;
710 next_scan_state
= SCAN_SUSPEND
;
711 } else if (associated
&& bad_latency
) {
712 next_scan_state
= SCAN_SUSPEND
;
714 next_scan_state
= SCAN_SET_CHANNEL
;
717 local
->next_scan_state
= next_scan_state
;
722 static void ieee80211_scan_state_set_channel(struct ieee80211_local
*local
,
723 unsigned long *next_delay
)
726 struct ieee80211_channel
*chan
;
727 enum nl80211_bss_scan_width oper_scan_width
;
728 struct cfg80211_scan_request
*scan_req
;
730 scan_req
= rcu_dereference_protected(local
->scan_req
,
731 lockdep_is_held(&local
->mtx
));
734 chan
= scan_req
->channels
[local
->scan_channel_idx
];
736 local
->scan_chandef
.chan
= chan
;
737 local
->scan_chandef
.center_freq1
= chan
->center_freq
;
738 local
->scan_chandef
.center_freq2
= 0;
739 switch (scan_req
->scan_width
) {
740 case NL80211_BSS_CHAN_WIDTH_5
:
741 local
->scan_chandef
.width
= NL80211_CHAN_WIDTH_5
;
743 case NL80211_BSS_CHAN_WIDTH_10
:
744 local
->scan_chandef
.width
= NL80211_CHAN_WIDTH_10
;
746 case NL80211_BSS_CHAN_WIDTH_20
:
747 /* If scanning on oper channel, use whatever channel-type
748 * is currently in use.
750 oper_scan_width
= cfg80211_chandef_to_scan_width(
751 &local
->_oper_chandef
);
752 if (chan
== local
->_oper_chandef
.chan
&&
753 oper_scan_width
== scan_req
->scan_width
)
754 local
->scan_chandef
= local
->_oper_chandef
;
756 local
->scan_chandef
.width
= NL80211_CHAN_WIDTH_20_NOHT
;
760 if (ieee80211_hw_config(local
, IEEE80211_CONF_CHANGE_CHANNEL
))
763 /* advance state machine to next channel/band */
764 local
->scan_channel_idx
++;
767 /* if we skip this channel return to the decision state */
768 local
->next_scan_state
= SCAN_DECISION
;
773 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
774 * (which unfortunately doesn't say _why_ step a) is done,
775 * but it waits for the probe delay or until a frame is
776 * received - and the received frame would update the NAV).
777 * For now, we do not support waiting until a frame is
780 * In any case, it is not necessary for a passive scan.
782 if (chan
->flags
& IEEE80211_CHAN_NO_IR
|| !scan_req
->n_ssids
) {
783 *next_delay
= IEEE80211_PASSIVE_CHANNEL_TIME
;
784 local
->next_scan_state
= SCAN_DECISION
;
788 /* active scan, send probes */
789 *next_delay
= IEEE80211_PROBE_DELAY
;
790 local
->next_scan_state
= SCAN_SEND_PROBE
;
793 static void ieee80211_scan_state_suspend(struct ieee80211_local
*local
,
794 unsigned long *next_delay
)
796 /* switch back to the operating channel */
797 local
->scan_chandef
.chan
= NULL
;
798 ieee80211_hw_config(local
, IEEE80211_CONF_CHANGE_CHANNEL
);
801 ieee80211_offchannel_return(local
);
803 *next_delay
= HZ
/ 5;
804 /* afterwards, resume scan & go to next channel */
805 local
->next_scan_state
= SCAN_RESUME
;
808 static void ieee80211_scan_state_resume(struct ieee80211_local
*local
,
809 unsigned long *next_delay
)
811 ieee80211_offchannel_stop_vifs(local
);
813 if (local
->ops
->flush
) {
814 ieee80211_flush_queues(local
, NULL
, false);
817 *next_delay
= HZ
/ 10;
819 /* remember when we left the operating channel */
820 local
->leave_oper_channel_time
= jiffies
;
822 /* advance to the next channel to be scanned */
823 local
->next_scan_state
= SCAN_SET_CHANNEL
;
826 void ieee80211_scan_work(struct work_struct
*work
)
828 struct ieee80211_local
*local
=
829 container_of(work
, struct ieee80211_local
, scan_work
.work
);
830 struct ieee80211_sub_if_data
*sdata
;
831 struct cfg80211_scan_request
*scan_req
;
832 unsigned long next_delay
= 0;
835 mutex_lock(&local
->mtx
);
837 if (!ieee80211_can_run_worker(local
)) {
842 sdata
= rcu_dereference_protected(local
->scan_sdata
,
843 lockdep_is_held(&local
->mtx
));
844 scan_req
= rcu_dereference_protected(local
->scan_req
,
845 lockdep_is_held(&local
->mtx
));
847 /* When scanning on-channel, the first-callback means completed. */
848 if (test_bit(SCAN_ONCHANNEL_SCANNING
, &local
->scanning
)) {
849 aborted
= test_and_clear_bit(SCAN_ABORTED
, &local
->scanning
);
853 if (test_and_clear_bit(SCAN_COMPLETED
, &local
->scanning
)) {
854 aborted
= test_and_clear_bit(SCAN_ABORTED
, &local
->scanning
);
858 if (!sdata
|| !scan_req
)
861 if (!local
->scanning
) {
864 RCU_INIT_POINTER(local
->scan_req
, NULL
);
865 RCU_INIT_POINTER(local
->scan_sdata
, NULL
);
867 rc
= __ieee80211_start_scan(sdata
, scan_req
);
869 /* need to complete scan in cfg80211 */
870 rcu_assign_pointer(local
->scan_req
, scan_req
);
878 * as long as no delay is required advance immediately
879 * without scheduling a new work
882 if (!ieee80211_sdata_running(sdata
)) {
887 switch (local
->next_scan_state
) {
889 /* if no more bands/channels left, complete scan */
890 if (local
->scan_channel_idx
>= scan_req
->n_channels
) {
894 ieee80211_scan_state_decision(local
, &next_delay
);
896 case SCAN_SET_CHANNEL
:
897 ieee80211_scan_state_set_channel(local
, &next_delay
);
899 case SCAN_SEND_PROBE
:
900 ieee80211_scan_state_send_probe(local
, &next_delay
);
903 ieee80211_scan_state_suspend(local
, &next_delay
);
906 ieee80211_scan_state_resume(local
, &next_delay
);
912 } while (next_delay
== 0);
914 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
, next_delay
);
918 __ieee80211_scan_completed(&local
->hw
, aborted
);
920 mutex_unlock(&local
->mtx
);
923 int ieee80211_request_scan(struct ieee80211_sub_if_data
*sdata
,
924 struct cfg80211_scan_request
*req
)
928 mutex_lock(&sdata
->local
->mtx
);
929 res
= __ieee80211_start_scan(sdata
, req
);
930 mutex_unlock(&sdata
->local
->mtx
);
935 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data
*sdata
,
936 const u8
*ssid
, u8 ssid_len
,
937 struct ieee80211_channel
**channels
,
938 unsigned int n_channels
,
939 enum nl80211_bss_scan_width scan_width
)
941 struct ieee80211_local
*local
= sdata
->local
;
942 int ret
= -EBUSY
, i
, n_ch
= 0;
943 enum ieee80211_band band
;
945 mutex_lock(&local
->mtx
);
951 /* fill internal scan request */
955 for (band
= 0; band
< IEEE80211_NUM_BANDS
; band
++) {
956 if (!local
->hw
.wiphy
->bands
[band
])
959 max_n
= local
->hw
.wiphy
->bands
[band
]->n_channels
;
960 for (i
= 0; i
< max_n
; i
++) {
961 struct ieee80211_channel
*tmp_ch
=
962 &local
->hw
.wiphy
->bands
[band
]->channels
[i
];
964 if (tmp_ch
->flags
& (IEEE80211_CHAN_NO_IR
|
965 IEEE80211_CHAN_DISABLED
))
968 local
->int_scan_req
->channels
[n_ch
] = tmp_ch
;
973 if (WARN_ON_ONCE(n_ch
== 0))
976 local
->int_scan_req
->n_channels
= n_ch
;
978 for (i
= 0; i
< n_channels
; i
++) {
979 if (channels
[i
]->flags
& (IEEE80211_CHAN_NO_IR
|
980 IEEE80211_CHAN_DISABLED
))
983 local
->int_scan_req
->channels
[n_ch
] = channels
[i
];
987 if (WARN_ON_ONCE(n_ch
== 0))
990 local
->int_scan_req
->n_channels
= n_ch
;
993 local
->int_scan_req
->ssids
= &local
->scan_ssid
;
994 local
->int_scan_req
->n_ssids
= 1;
995 local
->int_scan_req
->scan_width
= scan_width
;
996 memcpy(local
->int_scan_req
->ssids
[0].ssid
, ssid
, IEEE80211_MAX_SSID_LEN
);
997 local
->int_scan_req
->ssids
[0].ssid_len
= ssid_len
;
999 ret
= __ieee80211_start_scan(sdata
, sdata
->local
->int_scan_req
);
1001 mutex_unlock(&local
->mtx
);
1006 * Only call this function when a scan can't be queued -- under RTNL.
1008 void ieee80211_scan_cancel(struct ieee80211_local
*local
)
1011 * We are canceling software scan, or deferred scan that was not
1012 * yet really started (see __ieee80211_start_scan ).
1014 * Regarding hardware scan:
1015 * - we can not call __ieee80211_scan_completed() as when
1016 * SCAN_HW_SCANNING bit is set this function change
1017 * local->hw_scan_req to operate on 5G band, what race with
1018 * driver which can use local->hw_scan_req
1020 * - we can not cancel scan_work since driver can schedule it
1021 * by ieee80211_scan_completed(..., true) to finish scan
1023 * Hence we only call the cancel_hw_scan() callback, but the low-level
1024 * driver is still responsible for calling ieee80211_scan_completed()
1025 * after the scan was completed/aborted.
1028 mutex_lock(&local
->mtx
);
1029 if (!local
->scan_req
)
1033 * We have a scan running and the driver already reported completion,
1034 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1037 if (test_bit(SCAN_HW_SCANNING
, &local
->scanning
) &&
1038 test_bit(SCAN_COMPLETED
, &local
->scanning
)) {
1039 set_bit(SCAN_HW_CANCELLED
, &local
->scanning
);
1043 if (test_bit(SCAN_HW_SCANNING
, &local
->scanning
)) {
1045 * Make sure that __ieee80211_scan_completed doesn't trigger a
1046 * scan on another band.
1048 set_bit(SCAN_HW_CANCELLED
, &local
->scanning
);
1049 if (local
->ops
->cancel_hw_scan
)
1050 drv_cancel_hw_scan(local
,
1051 rcu_dereference_protected(local
->scan_sdata
,
1052 lockdep_is_held(&local
->mtx
)));
1057 * If the work is currently running, it must be blocked on
1058 * the mutex, but we'll set scan_sdata = NULL and it'll
1059 * simply exit once it acquires the mutex.
1061 cancel_delayed_work(&local
->scan_work
);
1063 __ieee80211_scan_completed(&local
->hw
, true);
1065 mutex_unlock(&local
->mtx
);
1068 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data
*sdata
,
1069 struct cfg80211_sched_scan_request
*req
)
1071 struct ieee80211_local
*local
= sdata
->local
;
1072 struct ieee80211_scan_ies sched_scan_ies
= {};
1073 struct cfg80211_chan_def chandef
;
1074 int ret
, i
, iebufsz
, num_bands
= 0;
1075 u32 rate_masks
[IEEE80211_NUM_BANDS
] = {};
1080 iebufsz
= local
->scan_ies_len
+ req
->ie_len
;
1082 lockdep_assert_held(&local
->mtx
);
1084 if (!local
->ops
->sched_scan_start
)
1087 for (i
= 0; i
< IEEE80211_NUM_BANDS
; i
++) {
1088 if (local
->hw
.wiphy
->bands
[i
]) {
1089 bands_used
|= BIT(i
);
1090 rate_masks
[i
] = (u32
) -1;
1095 ie
= kzalloc(num_bands
* iebufsz
, GFP_KERNEL
);
1101 ieee80211_prepare_scan_chandef(&chandef
, req
->scan_width
);
1103 len
= ieee80211_build_preq_ies(local
, ie
, num_bands
* iebufsz
,
1104 &sched_scan_ies
, req
->ie
,
1105 req
->ie_len
, bands_used
,
1106 rate_masks
, &chandef
);
1108 ret
= drv_sched_scan_start(local
, sdata
, req
, &sched_scan_ies
);
1110 rcu_assign_pointer(local
->sched_scan_sdata
, sdata
);
1111 rcu_assign_pointer(local
->sched_scan_req
, req
);
1118 /* Clean in case of failure after HW restart or upon resume. */
1119 RCU_INIT_POINTER(local
->sched_scan_sdata
, NULL
);
1120 RCU_INIT_POINTER(local
->sched_scan_req
, NULL
);
1126 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data
*sdata
,
1127 struct cfg80211_sched_scan_request
*req
)
1129 struct ieee80211_local
*local
= sdata
->local
;
1132 mutex_lock(&local
->mtx
);
1134 if (rcu_access_pointer(local
->sched_scan_sdata
)) {
1135 mutex_unlock(&local
->mtx
);
1139 ret
= __ieee80211_request_sched_scan_start(sdata
, req
);
1141 mutex_unlock(&local
->mtx
);
1145 int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data
*sdata
)
1147 struct ieee80211_local
*local
= sdata
->local
;
1150 mutex_lock(&local
->mtx
);
1152 if (!local
->ops
->sched_scan_stop
) {
1157 /* We don't want to restart sched scan anymore. */
1158 RCU_INIT_POINTER(local
->sched_scan_req
, NULL
);
1160 if (rcu_access_pointer(local
->sched_scan_sdata
)) {
1161 ret
= drv_sched_scan_stop(local
, sdata
);
1163 RCU_INIT_POINTER(local
->sched_scan_sdata
, NULL
);
1166 mutex_unlock(&local
->mtx
);
1171 void ieee80211_sched_scan_results(struct ieee80211_hw
*hw
)
1173 struct ieee80211_local
*local
= hw_to_local(hw
);
1175 trace_api_sched_scan_results(local
);
1177 cfg80211_sched_scan_results(hw
->wiphy
);
1179 EXPORT_SYMBOL(ieee80211_sched_scan_results
);
1181 void ieee80211_sched_scan_end(struct ieee80211_local
*local
)
1183 mutex_lock(&local
->mtx
);
1185 if (!rcu_access_pointer(local
->sched_scan_sdata
)) {
1186 mutex_unlock(&local
->mtx
);
1190 RCU_INIT_POINTER(local
->sched_scan_sdata
, NULL
);
1192 /* If sched scan was aborted by the driver. */
1193 RCU_INIT_POINTER(local
->sched_scan_req
, NULL
);
1195 mutex_unlock(&local
->mtx
);
1197 cfg80211_sched_scan_stopped(local
->hw
.wiphy
);
1200 void ieee80211_sched_scan_stopped_work(struct work_struct
*work
)
1202 struct ieee80211_local
*local
=
1203 container_of(work
, struct ieee80211_local
,
1204 sched_scan_stopped_work
);
1206 ieee80211_sched_scan_end(local
);
1209 void ieee80211_sched_scan_stopped(struct ieee80211_hw
*hw
)
1211 struct ieee80211_local
*local
= hw_to_local(hw
);
1213 trace_api_sched_scan_stopped(local
);
1215 schedule_work(&local
->sched_scan_stopped_work
);
1217 EXPORT_SYMBOL(ieee80211_sched_scan_stopped
);