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 2013-2014 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
;
73 if (local
->hw
.flags
& IEEE80211_HW_SIGNAL_DBM
)
74 signal
= rx_status
->signal
* 100;
75 else if (local
->hw
.flags
& IEEE80211_HW_SIGNAL_UNSPEC
)
76 signal
= (rx_status
->signal
* 100) / local
->hw
.max_signal
;
78 scan_width
= NL80211_BSS_CHAN_WIDTH_20
;
79 if (rx_status
->flag
& RX_FLAG_5MHZ
)
80 scan_width
= NL80211_BSS_CHAN_WIDTH_5
;
81 if (rx_status
->flag
& RX_FLAG_10MHZ
)
82 scan_width
= NL80211_BSS_CHAN_WIDTH_10
;
84 cbss
= cfg80211_inform_bss_width_frame(local
->hw
.wiphy
, channel
,
85 scan_width
, mgmt
, len
, signal
,
90 bss
= (void *)cbss
->priv
;
93 bss
->device_ts_beacon
= rx_status
->device_timestamp
;
95 bss
->device_ts_presp
= rx_status
->device_timestamp
;
97 if (elems
->parse_error
) {
99 bss
->corrupt_data
|= IEEE80211_BSS_CORRUPT_BEACON
;
101 bss
->corrupt_data
|= IEEE80211_BSS_CORRUPT_PROBE_RESP
;
104 bss
->corrupt_data
&= ~IEEE80211_BSS_CORRUPT_BEACON
;
106 bss
->corrupt_data
&= ~IEEE80211_BSS_CORRUPT_PROBE_RESP
;
109 /* save the ERP value so that it is available at association time */
110 if (elems
->erp_info
&& (!elems
->parse_error
||
111 !(bss
->valid_data
& IEEE80211_BSS_VALID_ERP
))) {
112 bss
->erp_value
= elems
->erp_info
[0];
113 bss
->has_erp_value
= true;
114 if (!elems
->parse_error
)
115 bss
->valid_data
|= IEEE80211_BSS_VALID_ERP
;
118 /* replace old supported rates if we get new values */
119 if (!elems
->parse_error
||
120 !(bss
->valid_data
& IEEE80211_BSS_VALID_RATES
)) {
122 if (elems
->supp_rates
) {
123 clen
= IEEE80211_MAX_SUPP_RATES
;
124 if (clen
> elems
->supp_rates_len
)
125 clen
= elems
->supp_rates_len
;
126 memcpy(bss
->supp_rates
, elems
->supp_rates
, clen
);
129 if (elems
->ext_supp_rates
) {
130 clen
= IEEE80211_MAX_SUPP_RATES
- srlen
;
131 if (clen
> elems
->ext_supp_rates_len
)
132 clen
= elems
->ext_supp_rates_len
;
133 memcpy(bss
->supp_rates
+ srlen
, elems
->ext_supp_rates
,
138 bss
->supp_rates_len
= srlen
;
139 if (!elems
->parse_error
)
140 bss
->valid_data
|= IEEE80211_BSS_VALID_RATES
;
144 if (!elems
->parse_error
||
145 !(bss
->valid_data
& IEEE80211_BSS_VALID_WMM
)) {
146 bss
->wmm_used
= elems
->wmm_param
|| elems
->wmm_info
;
147 bss
->uapsd_supported
= is_uapsd_supported(elems
);
148 if (!elems
->parse_error
)
149 bss
->valid_data
|= IEEE80211_BSS_VALID_WMM
;
153 struct ieee80211_supported_band
*sband
=
154 local
->hw
.wiphy
->bands
[rx_status
->band
];
155 if (!(rx_status
->flag
& RX_FLAG_HT
) &&
156 !(rx_status
->flag
& RX_FLAG_VHT
))
158 &sband
->bitrates
[rx_status
->rate_idx
];
164 void ieee80211_scan_rx(struct ieee80211_local
*local
, struct sk_buff
*skb
)
166 struct ieee80211_rx_status
*rx_status
= IEEE80211_SKB_RXCB(skb
);
167 struct ieee80211_sub_if_data
*sdata1
, *sdata2
;
168 struct ieee80211_mgmt
*mgmt
= (void *)skb
->data
;
169 struct ieee80211_bss
*bss
;
171 struct ieee80211_channel
*channel
;
173 struct ieee802_11_elems elems
;
176 (!ieee80211_is_probe_resp(mgmt
->frame_control
) &&
177 !ieee80211_is_beacon(mgmt
->frame_control
)))
180 sdata1
= rcu_dereference(local
->scan_sdata
);
181 sdata2
= rcu_dereference(local
->sched_scan_sdata
);
183 if (likely(!sdata1
&& !sdata2
))
186 if (ieee80211_is_probe_resp(mgmt
->frame_control
)) {
187 /* ignore ProbeResp to foreign address */
188 if ((!sdata1
|| !ether_addr_equal(mgmt
->da
, sdata1
->vif
.addr
)) &&
189 (!sdata2
|| !ether_addr_equal(mgmt
->da
, sdata2
->vif
.addr
)))
192 elements
= mgmt
->u
.probe_resp
.variable
;
193 baselen
= offsetof(struct ieee80211_mgmt
, u
.probe_resp
.variable
);
195 baselen
= offsetof(struct ieee80211_mgmt
, u
.beacon
.variable
);
196 elements
= mgmt
->u
.beacon
.variable
;
199 if (baselen
> skb
->len
)
202 ieee802_11_parse_elems(elements
, skb
->len
- baselen
, false, &elems
);
204 channel
= ieee80211_get_channel(local
->hw
.wiphy
, rx_status
->freq
);
206 if (!channel
|| channel
->flags
& IEEE80211_CHAN_DISABLED
)
209 bss
= ieee80211_bss_info_update(local
, rx_status
,
210 mgmt
, skb
->len
, &elems
,
213 ieee80211_rx_bss_put(local
, bss
);
217 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def
*chandef
,
218 enum nl80211_bss_scan_width scan_width
)
220 memset(chandef
, 0, sizeof(*chandef
));
221 switch (scan_width
) {
222 case NL80211_BSS_CHAN_WIDTH_5
:
223 chandef
->width
= NL80211_CHAN_WIDTH_5
;
225 case NL80211_BSS_CHAN_WIDTH_10
:
226 chandef
->width
= NL80211_CHAN_WIDTH_10
;
229 chandef
->width
= NL80211_CHAN_WIDTH_20_NOHT
;
234 /* return false if no more work */
235 static bool ieee80211_prep_hw_scan(struct ieee80211_local
*local
)
237 struct cfg80211_scan_request
*req
= local
->scan_req
;
238 struct cfg80211_chan_def chandef
;
240 int i
, ielen
, n_chans
;
242 if (test_bit(SCAN_HW_CANCELLED
, &local
->scanning
))
245 if (local
->hw
.flags
& IEEE80211_SINGLE_HW_SCAN_ON_ALL_BANDS
) {
246 for (i
= 0; i
< req
->n_channels
; i
++) {
247 local
->hw_scan_req
->req
.channels
[i
] = req
->channels
[i
];
248 bands_used
|= BIT(req
->channels
[i
]->band
);
251 n_chans
= req
->n_channels
;
254 if (local
->hw_scan_band
== IEEE80211_NUM_BANDS
)
259 for (i
= 0; i
< req
->n_channels
; i
++) {
260 if (req
->channels
[i
]->band
!=
263 local
->hw_scan_req
->req
.channels
[n_chans
] =
266 bands_used
|= BIT(req
->channels
[i
]->band
);
269 local
->hw_scan_band
++;
273 local
->hw_scan_req
->req
.n_channels
= n_chans
;
274 ieee80211_prepare_scan_chandef(&chandef
, req
->scan_width
);
276 ielen
= ieee80211_build_preq_ies(local
,
277 (u8
*)local
->hw_scan_req
->req
.ie
,
278 local
->hw_scan_ies_bufsize
,
279 &local
->hw_scan_req
->ies
,
280 req
->ie
, req
->ie_len
,
281 bands_used
, req
->rates
, &chandef
);
282 local
->hw_scan_req
->req
.ie_len
= ielen
;
283 local
->hw_scan_req
->req
.no_cck
= req
->no_cck
;
288 static void __ieee80211_scan_completed(struct ieee80211_hw
*hw
, bool aborted
)
290 struct ieee80211_local
*local
= hw_to_local(hw
);
291 bool hw_scan
= local
->ops
->hw_scan
;
292 bool was_scanning
= local
->scanning
;
294 lockdep_assert_held(&local
->mtx
);
297 * It's ok to abort a not-yet-running scan (that
298 * we have one at all will be verified by checking
299 * local->scan_req next), but not to complete it
302 if (WARN_ON(!local
->scanning
&& !aborted
))
305 if (WARN_ON(!local
->scan_req
))
308 if (hw_scan
&& !aborted
&&
309 !(local
->hw
.flags
& IEEE80211_SINGLE_HW_SCAN_ON_ALL_BANDS
) &&
310 ieee80211_prep_hw_scan(local
)) {
313 rc
= drv_hw_scan(local
,
314 rcu_dereference_protected(local
->scan_sdata
,
315 lockdep_is_held(&local
->mtx
)),
322 kfree(local
->hw_scan_req
);
323 local
->hw_scan_req
= NULL
;
325 if (local
->scan_req
!= local
->int_scan_req
)
326 cfg80211_scan_done(local
->scan_req
, aborted
);
327 local
->scan_req
= NULL
;
328 RCU_INIT_POINTER(local
->scan_sdata
, NULL
);
331 local
->scan_chandef
.chan
= NULL
;
333 /* Set power back to normal operating levels. */
334 ieee80211_hw_config(local
, 0);
337 ieee80211_configure_filter(local
);
338 drv_sw_scan_complete(local
);
339 ieee80211_offchannel_return(local
);
342 ieee80211_recalc_idle(local
);
344 ieee80211_mlme_notify_scan_completed(local
);
345 ieee80211_ibss_notify_scan_completed(local
);
346 ieee80211_mesh_notify_scan_completed(local
);
348 ieee80211_start_next_roc(local
);
351 void ieee80211_scan_completed(struct ieee80211_hw
*hw
, bool aborted
)
353 struct ieee80211_local
*local
= hw_to_local(hw
);
355 trace_api_scan_completed(local
, aborted
);
357 set_bit(SCAN_COMPLETED
, &local
->scanning
);
359 set_bit(SCAN_ABORTED
, &local
->scanning
);
360 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
, 0);
362 EXPORT_SYMBOL(ieee80211_scan_completed
);
364 static int ieee80211_start_sw_scan(struct ieee80211_local
*local
)
366 /* Software scan is not supported in multi-channel cases */
367 if (local
->use_chanctx
)
371 * Hardware/driver doesn't support hw_scan, so use software
372 * scanning instead. First send a nullfunc frame with power save
373 * bit on so that AP will buffer the frames for us while we are not
374 * listening, then send probe requests to each channel and wait for
375 * the responses. After all channels are scanned, tune back to the
376 * original channel and send a nullfunc frame with power save bit
377 * off to trigger the AP to send us all the buffered frames.
379 * Note that while local->sw_scanning is true everything else but
380 * nullfunc frames and probe requests will be dropped in
381 * ieee80211_tx_h_check_assoc().
383 drv_sw_scan_start(local
);
385 local
->leave_oper_channel_time
= jiffies
;
386 local
->next_scan_state
= SCAN_DECISION
;
387 local
->scan_channel_idx
= 0;
389 ieee80211_offchannel_stop_vifs(local
);
391 /* ensure nullfunc is transmitted before leaving operating channel */
392 ieee80211_flush_queues(local
, NULL
);
394 ieee80211_configure_filter(local
);
396 /* We need to set power level at maximum rate for scanning. */
397 ieee80211_hw_config(local
, 0);
399 ieee80211_queue_delayed_work(&local
->hw
,
400 &local
->scan_work
, 0);
405 static bool ieee80211_can_scan(struct ieee80211_local
*local
,
406 struct ieee80211_sub_if_data
*sdata
)
408 if (local
->radar_detect_enabled
)
411 if (!list_empty(&local
->roc_list
))
414 if (sdata
->vif
.type
== NL80211_IFTYPE_STATION
&&
415 sdata
->u
.mgd
.flags
& IEEE80211_STA_CONNECTION_POLL
)
421 void ieee80211_run_deferred_scan(struct ieee80211_local
*local
)
423 lockdep_assert_held(&local
->mtx
);
425 if (!local
->scan_req
|| local
->scanning
)
428 if (!ieee80211_can_scan(local
,
429 rcu_dereference_protected(
431 lockdep_is_held(&local
->mtx
))))
434 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
,
435 round_jiffies_relative(0));
438 static void ieee80211_scan_state_send_probe(struct ieee80211_local
*local
,
439 unsigned long *next_delay
)
442 struct ieee80211_sub_if_data
*sdata
;
443 enum ieee80211_band band
= local
->hw
.conf
.chandef
.chan
->band
;
446 tx_flags
= IEEE80211_TX_INTFL_OFFCHAN_TX_OK
;
447 if (local
->scan_req
->no_cck
)
448 tx_flags
|= IEEE80211_TX_CTL_NO_CCK_RATE
;
450 sdata
= rcu_dereference_protected(local
->scan_sdata
,
451 lockdep_is_held(&local
->mtx
));
453 for (i
= 0; i
< local
->scan_req
->n_ssids
; i
++)
454 ieee80211_send_probe_req(
456 local
->scan_req
->ssids
[i
].ssid
,
457 local
->scan_req
->ssids
[i
].ssid_len
,
458 local
->scan_req
->ie
, local
->scan_req
->ie_len
,
459 local
->scan_req
->rates
[band
], false,
460 tx_flags
, local
->hw
.conf
.chandef
.chan
, true);
463 * After sending probe requests, wait for probe responses
466 *next_delay
= IEEE80211_CHANNEL_TIME
;
467 local
->next_scan_state
= SCAN_DECISION
;
470 static int __ieee80211_start_scan(struct ieee80211_sub_if_data
*sdata
,
471 struct cfg80211_scan_request
*req
)
473 struct ieee80211_local
*local
= sdata
->local
;
476 lockdep_assert_held(&local
->mtx
);
481 if (!ieee80211_can_scan(local
, sdata
)) {
482 /* wait for the work to finish/time out */
483 local
->scan_req
= req
;
484 rcu_assign_pointer(local
->scan_sdata
, sdata
);
488 if (local
->ops
->hw_scan
) {
491 local
->hw_scan_ies_bufsize
= local
->scan_ies_len
+ req
->ie_len
;
493 if (local
->hw
.flags
& IEEE80211_SINGLE_HW_SCAN_ON_ALL_BANDS
) {
495 u8 bands_counted
= 0;
497 for (i
= 0; i
< req
->n_channels
; i
++) {
498 if (bands_counted
& BIT(req
->channels
[i
]->band
))
500 bands_counted
|= BIT(req
->channels
[i
]->band
);
504 local
->hw_scan_ies_bufsize
*= n_bands
;
507 local
->hw_scan_req
= kmalloc(
508 sizeof(*local
->hw_scan_req
) +
509 req
->n_channels
* sizeof(req
->channels
[0]) +
510 local
->hw_scan_ies_bufsize
, GFP_KERNEL
);
511 if (!local
->hw_scan_req
)
514 local
->hw_scan_req
->req
.ssids
= req
->ssids
;
515 local
->hw_scan_req
->req
.n_ssids
= req
->n_ssids
;
516 ies
= (u8
*)local
->hw_scan_req
+
517 sizeof(*local
->hw_scan_req
) +
518 req
->n_channels
* sizeof(req
->channels
[0]);
519 local
->hw_scan_req
->req
.ie
= ies
;
520 local
->hw_scan_req
->req
.flags
= req
->flags
;
522 local
->hw_scan_band
= 0;
525 * After allocating local->hw_scan_req, we must
526 * go through until ieee80211_prep_hw_scan(), so
527 * anything that might be changed here and leave
528 * this function early must not go after this
533 local
->scan_req
= req
;
534 rcu_assign_pointer(local
->scan_sdata
, sdata
);
536 if (local
->ops
->hw_scan
) {
537 __set_bit(SCAN_HW_SCANNING
, &local
->scanning
);
538 } else if ((req
->n_channels
== 1) &&
539 (req
->channels
[0] == local
->_oper_chandef
.chan
)) {
541 * If we are scanning only on the operating channel
542 * then we do not need to stop normal activities
544 unsigned long next_delay
;
546 __set_bit(SCAN_ONCHANNEL_SCANNING
, &local
->scanning
);
548 ieee80211_recalc_idle(local
);
550 /* Notify driver scan is starting, keep order of operations
551 * same as normal software scan, in case that matters. */
552 drv_sw_scan_start(local
);
554 ieee80211_configure_filter(local
); /* accept probe-responses */
556 /* We need to ensure power level is at max for scanning. */
557 ieee80211_hw_config(local
, 0);
559 if ((req
->channels
[0]->flags
&
560 IEEE80211_CHAN_NO_IR
) ||
561 !local
->scan_req
->n_ssids
) {
562 next_delay
= IEEE80211_PASSIVE_CHANNEL_TIME
;
564 ieee80211_scan_state_send_probe(local
, &next_delay
);
565 next_delay
= IEEE80211_CHANNEL_TIME
;
568 /* Now, just wait a bit and we are all done! */
569 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
,
573 /* Do normal software scan */
574 __set_bit(SCAN_SW_SCANNING
, &local
->scanning
);
577 ieee80211_recalc_idle(local
);
579 if (local
->ops
->hw_scan
) {
580 WARN_ON(!ieee80211_prep_hw_scan(local
));
581 rc
= drv_hw_scan(local
, sdata
, local
->hw_scan_req
);
583 rc
= ieee80211_start_sw_scan(local
);
586 kfree(local
->hw_scan_req
);
587 local
->hw_scan_req
= NULL
;
590 ieee80211_recalc_idle(local
);
592 local
->scan_req
= NULL
;
593 RCU_INIT_POINTER(local
->scan_sdata
, NULL
);
600 ieee80211_scan_get_channel_time(struct ieee80211_channel
*chan
)
603 * TODO: channel switching also consumes quite some time,
604 * add that delay as well to get a better estimation
606 if (chan
->flags
& IEEE80211_CHAN_NO_IR
)
607 return IEEE80211_PASSIVE_CHANNEL_TIME
;
608 return IEEE80211_PROBE_DELAY
+ IEEE80211_CHANNEL_TIME
;
611 static void ieee80211_scan_state_decision(struct ieee80211_local
*local
,
612 unsigned long *next_delay
)
614 bool associated
= false;
615 bool tx_empty
= true;
617 struct ieee80211_sub_if_data
*sdata
;
618 struct ieee80211_channel
*next_chan
;
619 enum mac80211_scan_state next_scan_state
;
622 * check if at least one STA interface is associated,
623 * check if at least one STA interface has pending tx frames
624 * and grab the lowest used beacon interval
626 mutex_lock(&local
->iflist_mtx
);
627 list_for_each_entry(sdata
, &local
->interfaces
, list
) {
628 if (!ieee80211_sdata_running(sdata
))
631 if (sdata
->vif
.type
== NL80211_IFTYPE_STATION
) {
632 if (sdata
->u
.mgd
.associated
) {
635 if (!qdisc_all_tx_empty(sdata
->dev
)) {
642 mutex_unlock(&local
->iflist_mtx
);
644 next_chan
= local
->scan_req
->channels
[local
->scan_channel_idx
];
647 * we're currently scanning a different channel, let's
648 * see if we can scan another channel without interfering
649 * with the current traffic situation.
651 * Keep good latency, do not stay off-channel more than 125 ms.
654 bad_latency
= time_after(jiffies
+
655 ieee80211_scan_get_channel_time(next_chan
),
656 local
->leave_oper_channel_time
+ HZ
/ 8);
658 if (associated
&& !tx_empty
) {
659 if (local
->scan_req
->flags
& NL80211_SCAN_FLAG_LOW_PRIORITY
)
660 next_scan_state
= SCAN_ABORT
;
662 next_scan_state
= SCAN_SUSPEND
;
663 } else if (associated
&& bad_latency
) {
664 next_scan_state
= SCAN_SUSPEND
;
666 next_scan_state
= SCAN_SET_CHANNEL
;
669 local
->next_scan_state
= next_scan_state
;
674 static void ieee80211_scan_state_set_channel(struct ieee80211_local
*local
,
675 unsigned long *next_delay
)
678 struct ieee80211_channel
*chan
;
679 enum nl80211_bss_scan_width oper_scan_width
;
682 chan
= local
->scan_req
->channels
[local
->scan_channel_idx
];
684 local
->scan_chandef
.chan
= chan
;
685 local
->scan_chandef
.center_freq1
= chan
->center_freq
;
686 local
->scan_chandef
.center_freq2
= 0;
687 switch (local
->scan_req
->scan_width
) {
688 case NL80211_BSS_CHAN_WIDTH_5
:
689 local
->scan_chandef
.width
= NL80211_CHAN_WIDTH_5
;
691 case NL80211_BSS_CHAN_WIDTH_10
:
692 local
->scan_chandef
.width
= NL80211_CHAN_WIDTH_10
;
694 case NL80211_BSS_CHAN_WIDTH_20
:
695 /* If scanning on oper channel, use whatever channel-type
696 * is currently in use.
698 oper_scan_width
= cfg80211_chandef_to_scan_width(
699 &local
->_oper_chandef
);
700 if (chan
== local
->_oper_chandef
.chan
&&
701 oper_scan_width
== local
->scan_req
->scan_width
)
702 local
->scan_chandef
= local
->_oper_chandef
;
704 local
->scan_chandef
.width
= NL80211_CHAN_WIDTH_20_NOHT
;
708 if (ieee80211_hw_config(local
, IEEE80211_CONF_CHANGE_CHANNEL
))
711 /* advance state machine to next channel/band */
712 local
->scan_channel_idx
++;
715 /* if we skip this channel return to the decision state */
716 local
->next_scan_state
= SCAN_DECISION
;
721 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
722 * (which unfortunately doesn't say _why_ step a) is done,
723 * but it waits for the probe delay or until a frame is
724 * received - and the received frame would update the NAV).
725 * For now, we do not support waiting until a frame is
728 * In any case, it is not necessary for a passive scan.
730 if (chan
->flags
& IEEE80211_CHAN_NO_IR
||
731 !local
->scan_req
->n_ssids
) {
732 *next_delay
= IEEE80211_PASSIVE_CHANNEL_TIME
;
733 local
->next_scan_state
= SCAN_DECISION
;
737 /* active scan, send probes */
738 *next_delay
= IEEE80211_PROBE_DELAY
;
739 local
->next_scan_state
= SCAN_SEND_PROBE
;
742 static void ieee80211_scan_state_suspend(struct ieee80211_local
*local
,
743 unsigned long *next_delay
)
745 /* switch back to the operating channel */
746 local
->scan_chandef
.chan
= NULL
;
747 ieee80211_hw_config(local
, IEEE80211_CONF_CHANGE_CHANNEL
);
750 ieee80211_offchannel_return(local
);
752 *next_delay
= HZ
/ 5;
753 /* afterwards, resume scan & go to next channel */
754 local
->next_scan_state
= SCAN_RESUME
;
757 static void ieee80211_scan_state_resume(struct ieee80211_local
*local
,
758 unsigned long *next_delay
)
760 ieee80211_offchannel_stop_vifs(local
);
762 if (local
->ops
->flush
) {
763 ieee80211_flush_queues(local
, NULL
);
766 *next_delay
= HZ
/ 10;
768 /* remember when we left the operating channel */
769 local
->leave_oper_channel_time
= jiffies
;
771 /* advance to the next channel to be scanned */
772 local
->next_scan_state
= SCAN_SET_CHANNEL
;
775 void ieee80211_scan_work(struct work_struct
*work
)
777 struct ieee80211_local
*local
=
778 container_of(work
, struct ieee80211_local
, scan_work
.work
);
779 struct ieee80211_sub_if_data
*sdata
;
780 unsigned long next_delay
= 0;
783 mutex_lock(&local
->mtx
);
785 sdata
= rcu_dereference_protected(local
->scan_sdata
,
786 lockdep_is_held(&local
->mtx
));
788 /* When scanning on-channel, the first-callback means completed. */
789 if (test_bit(SCAN_ONCHANNEL_SCANNING
, &local
->scanning
)) {
790 aborted
= test_and_clear_bit(SCAN_ABORTED
, &local
->scanning
);
794 if (test_and_clear_bit(SCAN_COMPLETED
, &local
->scanning
)) {
795 aborted
= test_and_clear_bit(SCAN_ABORTED
, &local
->scanning
);
799 if (!sdata
|| !local
->scan_req
)
802 if (local
->scan_req
&& !local
->scanning
) {
803 struct cfg80211_scan_request
*req
= local
->scan_req
;
806 local
->scan_req
= NULL
;
807 RCU_INIT_POINTER(local
->scan_sdata
, NULL
);
809 rc
= __ieee80211_start_scan(sdata
, req
);
811 /* need to complete scan in cfg80211 */
812 local
->scan_req
= req
;
820 * as long as no delay is required advance immediately
821 * without scheduling a new work
824 if (!ieee80211_sdata_running(sdata
)) {
829 switch (local
->next_scan_state
) {
831 /* if no more bands/channels left, complete scan */
832 if (local
->scan_channel_idx
>= local
->scan_req
->n_channels
) {
836 ieee80211_scan_state_decision(local
, &next_delay
);
838 case SCAN_SET_CHANNEL
:
839 ieee80211_scan_state_set_channel(local
, &next_delay
);
841 case SCAN_SEND_PROBE
:
842 ieee80211_scan_state_send_probe(local
, &next_delay
);
845 ieee80211_scan_state_suspend(local
, &next_delay
);
848 ieee80211_scan_state_resume(local
, &next_delay
);
854 } while (next_delay
== 0);
856 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
, next_delay
);
860 __ieee80211_scan_completed(&local
->hw
, aborted
);
862 mutex_unlock(&local
->mtx
);
865 int ieee80211_request_scan(struct ieee80211_sub_if_data
*sdata
,
866 struct cfg80211_scan_request
*req
)
870 mutex_lock(&sdata
->local
->mtx
);
871 res
= __ieee80211_start_scan(sdata
, req
);
872 mutex_unlock(&sdata
->local
->mtx
);
877 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data
*sdata
,
878 const u8
*ssid
, u8 ssid_len
,
879 struct ieee80211_channel
*chan
,
880 enum nl80211_bss_scan_width scan_width
)
882 struct ieee80211_local
*local
= sdata
->local
;
884 enum ieee80211_band band
;
886 mutex_lock(&local
->mtx
);
892 /* fill internal scan request */
897 for (band
= 0; band
< IEEE80211_NUM_BANDS
; band
++) {
898 if (!local
->hw
.wiphy
->bands
[band
])
901 max_n
= local
->hw
.wiphy
->bands
[band
]->n_channels
;
902 for (i
= 0; i
< max_n
; i
++) {
903 struct ieee80211_channel
*tmp_ch
=
904 &local
->hw
.wiphy
->bands
[band
]->channels
[i
];
906 if (tmp_ch
->flags
& (IEEE80211_CHAN_NO_IR
|
907 IEEE80211_CHAN_DISABLED
))
910 local
->int_scan_req
->channels
[n_ch
] = tmp_ch
;
915 if (WARN_ON_ONCE(n_ch
== 0))
918 local
->int_scan_req
->n_channels
= n_ch
;
920 if (WARN_ON_ONCE(chan
->flags
& (IEEE80211_CHAN_NO_IR
|
921 IEEE80211_CHAN_DISABLED
)))
924 local
->int_scan_req
->channels
[0] = chan
;
925 local
->int_scan_req
->n_channels
= 1;
928 local
->int_scan_req
->ssids
= &local
->scan_ssid
;
929 local
->int_scan_req
->n_ssids
= 1;
930 local
->int_scan_req
->scan_width
= scan_width
;
931 memcpy(local
->int_scan_req
->ssids
[0].ssid
, ssid
, IEEE80211_MAX_SSID_LEN
);
932 local
->int_scan_req
->ssids
[0].ssid_len
= ssid_len
;
934 ret
= __ieee80211_start_scan(sdata
, sdata
->local
->int_scan_req
);
936 mutex_unlock(&local
->mtx
);
941 * Only call this function when a scan can't be queued -- under RTNL.
943 void ieee80211_scan_cancel(struct ieee80211_local
*local
)
946 * We are canceling software scan, or deferred scan that was not
947 * yet really started (see __ieee80211_start_scan ).
949 * Regarding hardware scan:
950 * - we can not call __ieee80211_scan_completed() as when
951 * SCAN_HW_SCANNING bit is set this function change
952 * local->hw_scan_req to operate on 5G band, what race with
953 * driver which can use local->hw_scan_req
955 * - we can not cancel scan_work since driver can schedule it
956 * by ieee80211_scan_completed(..., true) to finish scan
958 * Hence we only call the cancel_hw_scan() callback, but the low-level
959 * driver is still responsible for calling ieee80211_scan_completed()
960 * after the scan was completed/aborted.
963 mutex_lock(&local
->mtx
);
964 if (!local
->scan_req
)
968 * We have a scan running and the driver already reported completion,
969 * but the worker hasn't run yet or is stuck on the mutex - mark it as
972 if (test_bit(SCAN_HW_SCANNING
, &local
->scanning
) &&
973 test_bit(SCAN_COMPLETED
, &local
->scanning
)) {
974 set_bit(SCAN_HW_CANCELLED
, &local
->scanning
);
978 if (test_bit(SCAN_HW_SCANNING
, &local
->scanning
)) {
980 * Make sure that __ieee80211_scan_completed doesn't trigger a
981 * scan on another band.
983 set_bit(SCAN_HW_CANCELLED
, &local
->scanning
);
984 if (local
->ops
->cancel_hw_scan
)
985 drv_cancel_hw_scan(local
,
986 rcu_dereference_protected(local
->scan_sdata
,
987 lockdep_is_held(&local
->mtx
)));
992 * If the work is currently running, it must be blocked on
993 * the mutex, but we'll set scan_sdata = NULL and it'll
994 * simply exit once it acquires the mutex.
996 cancel_delayed_work(&local
->scan_work
);
998 __ieee80211_scan_completed(&local
->hw
, true);
1000 mutex_unlock(&local
->mtx
);
1003 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data
*sdata
,
1004 struct cfg80211_sched_scan_request
*req
)
1006 struct ieee80211_local
*local
= sdata
->local
;
1007 struct ieee80211_scan_ies sched_scan_ies
= {};
1008 struct cfg80211_chan_def chandef
;
1009 int ret
, i
, iebufsz
, num_bands
= 0;
1010 u32 rate_masks
[IEEE80211_NUM_BANDS
] = {};
1015 iebufsz
= local
->scan_ies_len
+ req
->ie_len
;
1017 lockdep_assert_held(&local
->mtx
);
1019 if (!local
->ops
->sched_scan_start
)
1022 for (i
= 0; i
< IEEE80211_NUM_BANDS
; i
++) {
1023 if (local
->hw
.wiphy
->bands
[i
]) {
1024 bands_used
|= BIT(i
);
1025 rate_masks
[i
] = (u32
) -1;
1030 ie
= kzalloc(num_bands
* iebufsz
, GFP_KERNEL
);
1036 ieee80211_prepare_scan_chandef(&chandef
, req
->scan_width
);
1038 len
= ieee80211_build_preq_ies(local
, ie
, num_bands
* iebufsz
,
1039 &sched_scan_ies
, req
->ie
,
1040 req
->ie_len
, bands_used
,
1041 rate_masks
, &chandef
);
1043 ret
= drv_sched_scan_start(local
, sdata
, req
, &sched_scan_ies
);
1045 rcu_assign_pointer(local
->sched_scan_sdata
, sdata
);
1046 local
->sched_scan_req
= req
;
1053 /* Clean in case of failure after HW restart or upon resume. */
1054 RCU_INIT_POINTER(local
->sched_scan_sdata
, NULL
);
1055 local
->sched_scan_req
= NULL
;
1061 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data
*sdata
,
1062 struct cfg80211_sched_scan_request
*req
)
1064 struct ieee80211_local
*local
= sdata
->local
;
1067 mutex_lock(&local
->mtx
);
1069 if (rcu_access_pointer(local
->sched_scan_sdata
)) {
1070 mutex_unlock(&local
->mtx
);
1074 ret
= __ieee80211_request_sched_scan_start(sdata
, req
);
1076 mutex_unlock(&local
->mtx
);
1080 int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data
*sdata
)
1082 struct ieee80211_local
*local
= sdata
->local
;
1085 mutex_lock(&local
->mtx
);
1087 if (!local
->ops
->sched_scan_stop
) {
1092 /* We don't want to restart sched scan anymore. */
1093 local
->sched_scan_req
= NULL
;
1095 if (rcu_access_pointer(local
->sched_scan_sdata
)) {
1096 ret
= drv_sched_scan_stop(local
, sdata
);
1098 RCU_INIT_POINTER(local
->sched_scan_sdata
, NULL
);
1101 mutex_unlock(&local
->mtx
);
1106 void ieee80211_sched_scan_results(struct ieee80211_hw
*hw
)
1108 struct ieee80211_local
*local
= hw_to_local(hw
);
1110 trace_api_sched_scan_results(local
);
1112 cfg80211_sched_scan_results(hw
->wiphy
);
1114 EXPORT_SYMBOL(ieee80211_sched_scan_results
);
1116 void ieee80211_sched_scan_end(struct ieee80211_local
*local
)
1118 mutex_lock(&local
->mtx
);
1120 if (!rcu_access_pointer(local
->sched_scan_sdata
)) {
1121 mutex_unlock(&local
->mtx
);
1125 RCU_INIT_POINTER(local
->sched_scan_sdata
, NULL
);
1127 /* If sched scan was aborted by the driver. */
1128 local
->sched_scan_req
= NULL
;
1130 mutex_unlock(&local
->mtx
);
1132 cfg80211_sched_scan_stopped(local
->hw
.wiphy
);
1135 void ieee80211_sched_scan_stopped_work(struct work_struct
*work
)
1137 struct ieee80211_local
*local
=
1138 container_of(work
, struct ieee80211_local
,
1139 sched_scan_stopped_work
);
1141 ieee80211_sched_scan_end(local
);
1144 void ieee80211_sched_scan_stopped(struct ieee80211_hw
*hw
)
1146 struct ieee80211_local
*local
= hw_to_local(hw
);
1148 trace_api_sched_scan_stopped(local
);
1150 schedule_work(&local
->sched_scan_stopped_work
);
1152 EXPORT_SYMBOL(ieee80211_sched_scan_stopped
);