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>
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.
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>
24 #include "ieee80211_i.h"
25 #include "driver-ops.h"
28 #define IEEE80211_PROBE_DELAY (HZ / 33)
29 #define IEEE80211_CHANNEL_TIME (HZ / 33)
30 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
32 void ieee80211_rx_bss_put(struct ieee80211_local
*local
,
33 struct ieee80211_bss
*bss
)
37 cfg80211_put_bss(local
->hw
.wiphy
,
38 container_of((void *)bss
, struct cfg80211_bss
, priv
));
41 static bool is_uapsd_supported(struct ieee802_11_elems
*elems
)
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];
52 /* no valid wmm information or parameter element found */
55 return qos_info
& IEEE80211_WMM_IE_AP_QOSINFO_UAPSD
;
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
)
65 bool beacon
= ieee80211_is_beacon(mgmt
->frame_control
);
66 struct cfg80211_bss
*cbss
;
67 struct ieee80211_bss
*bss
;
69 enum nl80211_bss_scan_width scan_width
;
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
;
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
;
83 cbss
= cfg80211_inform_bss_width_frame(local
->hw
.wiphy
, channel
,
84 scan_width
, mgmt
, len
, signal
,
89 bss
= (void *)cbss
->priv
;
92 bss
->device_ts_beacon
= rx_status
->device_timestamp
;
94 bss
->device_ts_presp
= rx_status
->device_timestamp
;
96 if (elems
->parse_error
) {
98 bss
->corrupt_data
|= IEEE80211_BSS_CORRUPT_BEACON
;
100 bss
->corrupt_data
|= IEEE80211_BSS_CORRUPT_PROBE_RESP
;
103 bss
->corrupt_data
&= ~IEEE80211_BSS_CORRUPT_BEACON
;
105 bss
->corrupt_data
&= ~IEEE80211_BSS_CORRUPT_PROBE_RESP
;
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
;
117 /* replace old supported rates if we get new values */
118 if (!elems
->parse_error
||
119 !(bss
->valid_data
& IEEE80211_BSS_VALID_RATES
)) {
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
);
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
,
137 bss
->supp_rates_len
= srlen
;
138 if (!elems
->parse_error
)
139 bss
->valid_data
|= IEEE80211_BSS_VALID_RATES
;
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
;
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
))
157 &sband
->bitrates
[rx_status
->rate_idx
];
163 void ieee80211_scan_rx(struct ieee80211_local
*local
, struct sk_buff
*skb
)
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
;
170 struct ieee80211_channel
*channel
;
172 struct ieee802_11_elems elems
;
175 (!ieee80211_is_probe_resp(mgmt
->frame_control
) &&
176 !ieee80211_is_beacon(mgmt
->frame_control
)))
179 sdata1
= rcu_dereference(local
->scan_sdata
);
180 sdata2
= rcu_dereference(local
->sched_scan_sdata
);
182 if (likely(!sdata1
&& !sdata2
))
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
)))
191 elements
= mgmt
->u
.probe_resp
.variable
;
192 baselen
= offsetof(struct ieee80211_mgmt
, u
.probe_resp
.variable
);
194 baselen
= offsetof(struct ieee80211_mgmt
, u
.beacon
.variable
);
195 elements
= mgmt
->u
.beacon
.variable
;
198 if (baselen
> skb
->len
)
201 ieee802_11_parse_elems(elements
, skb
->len
- baselen
, false, &elems
);
203 channel
= ieee80211_get_channel(local
->hw
.wiphy
, rx_status
->freq
);
205 if (!channel
|| channel
->flags
& IEEE80211_CHAN_DISABLED
)
208 bss
= ieee80211_bss_info_update(local
, rx_status
,
209 mgmt
, skb
->len
, &elems
,
212 ieee80211_rx_bss_put(local
, bss
);
216 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def
*chandef
,
217 enum nl80211_bss_scan_width scan_width
)
219 memset(chandef
, 0, sizeof(*chandef
));
220 switch (scan_width
) {
221 case NL80211_BSS_CHAN_WIDTH_5
:
222 chandef
->width
= NL80211_CHAN_WIDTH_5
;
224 case NL80211_BSS_CHAN_WIDTH_10
:
225 chandef
->width
= NL80211_CHAN_WIDTH_10
;
228 chandef
->width
= NL80211_CHAN_WIDTH_20_NOHT
;
233 /* return false if no more work */
234 static bool ieee80211_prep_hw_scan(struct ieee80211_local
*local
)
236 struct cfg80211_scan_request
*req
= local
->scan_req
;
237 struct cfg80211_chan_def chandef
;
239 int i
, ielen
, n_chans
;
241 if (test_bit(SCAN_HW_CANCELLED
, &local
->scanning
))
244 if (local
->hw
.flags
& IEEE80211_SINGLE_HW_SCAN_ON_ALL_BANDS
) {
245 for (i
= 0; i
< req
->n_channels
; i
++) {
246 local
->hw_scan_req
->req
.channels
[i
] = req
->channels
[i
];
247 bands_used
|= BIT(req
->channels
[i
]->band
);
250 n_chans
= req
->n_channels
;
253 if (local
->hw_scan_band
== IEEE80211_NUM_BANDS
)
258 for (i
= 0; i
< req
->n_channels
; i
++) {
259 if (req
->channels
[i
]->band
!=
262 local
->hw_scan_req
->req
.channels
[n_chans
] =
265 bands_used
|= BIT(req
->channels
[i
]->band
);
268 local
->hw_scan_band
++;
272 local
->hw_scan_req
->req
.n_channels
= n_chans
;
273 ieee80211_prepare_scan_chandef(&chandef
, req
->scan_width
);
275 ielen
= ieee80211_build_preq_ies(local
,
276 (u8
*)local
->hw_scan_req
->req
.ie
,
277 local
->hw_scan_ies_bufsize
,
278 &local
->hw_scan_req
->ies
,
279 req
->ie
, req
->ie_len
,
280 bands_used
, req
->rates
, &chandef
);
281 local
->hw_scan_req
->req
.ie_len
= ielen
;
282 local
->hw_scan_req
->req
.no_cck
= req
->no_cck
;
287 static void __ieee80211_scan_completed(struct ieee80211_hw
*hw
, bool aborted
)
289 struct ieee80211_local
*local
= hw_to_local(hw
);
290 bool hw_scan
= local
->ops
->hw_scan
;
291 bool was_scanning
= local
->scanning
;
293 lockdep_assert_held(&local
->mtx
);
296 * It's ok to abort a not-yet-running scan (that
297 * we have one at all will be verified by checking
298 * local->scan_req next), but not to complete it
301 if (WARN_ON(!local
->scanning
&& !aborted
))
304 if (WARN_ON(!local
->scan_req
))
307 if (hw_scan
&& !aborted
&&
308 !(local
->hw
.flags
& IEEE80211_SINGLE_HW_SCAN_ON_ALL_BANDS
) &&
309 ieee80211_prep_hw_scan(local
)) {
312 rc
= drv_hw_scan(local
,
313 rcu_dereference_protected(local
->scan_sdata
,
314 lockdep_is_held(&local
->mtx
)),
321 kfree(local
->hw_scan_req
);
322 local
->hw_scan_req
= NULL
;
324 if (local
->scan_req
!= local
->int_scan_req
)
325 cfg80211_scan_done(local
->scan_req
, aborted
);
326 local
->scan_req
= NULL
;
327 RCU_INIT_POINTER(local
->scan_sdata
, NULL
);
330 local
->scan_chandef
.chan
= NULL
;
332 /* Set power back to normal operating levels. */
333 ieee80211_hw_config(local
, 0);
336 ieee80211_configure_filter(local
);
337 drv_sw_scan_complete(local
);
338 ieee80211_offchannel_return(local
);
341 ieee80211_recalc_idle(local
);
343 ieee80211_mlme_notify_scan_completed(local
);
344 ieee80211_ibss_notify_scan_completed(local
);
345 ieee80211_mesh_notify_scan_completed(local
);
347 ieee80211_start_next_roc(local
);
350 void ieee80211_scan_completed(struct ieee80211_hw
*hw
, bool aborted
)
352 struct ieee80211_local
*local
= hw_to_local(hw
);
354 trace_api_scan_completed(local
, aborted
);
356 set_bit(SCAN_COMPLETED
, &local
->scanning
);
358 set_bit(SCAN_ABORTED
, &local
->scanning
);
359 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
, 0);
361 EXPORT_SYMBOL(ieee80211_scan_completed
);
363 static int ieee80211_start_sw_scan(struct ieee80211_local
*local
)
365 /* Software scan is not supported in multi-channel cases */
366 if (local
->use_chanctx
)
370 * Hardware/driver doesn't support hw_scan, so use software
371 * scanning instead. First send a nullfunc frame with power save
372 * bit on so that AP will buffer the frames for us while we are not
373 * listening, then send probe requests to each channel and wait for
374 * the responses. After all channels are scanned, tune back to the
375 * original channel and send a nullfunc frame with power save bit
376 * off to trigger the AP to send us all the buffered frames.
378 * Note that while local->sw_scanning is true everything else but
379 * nullfunc frames and probe requests will be dropped in
380 * ieee80211_tx_h_check_assoc().
382 drv_sw_scan_start(local
);
384 local
->leave_oper_channel_time
= jiffies
;
385 local
->next_scan_state
= SCAN_DECISION
;
386 local
->scan_channel_idx
= 0;
388 ieee80211_offchannel_stop_vifs(local
);
390 /* ensure nullfunc is transmitted before leaving operating channel */
391 ieee80211_flush_queues(local
, NULL
);
393 ieee80211_configure_filter(local
);
395 /* We need to set power level at maximum rate for scanning. */
396 ieee80211_hw_config(local
, 0);
398 ieee80211_queue_delayed_work(&local
->hw
,
399 &local
->scan_work
, 0);
404 static bool ieee80211_can_scan(struct ieee80211_local
*local
,
405 struct ieee80211_sub_if_data
*sdata
)
407 if (local
->radar_detect_enabled
)
410 if (!list_empty(&local
->roc_list
))
413 if (sdata
->vif
.type
== NL80211_IFTYPE_STATION
&&
414 sdata
->u
.mgd
.flags
& IEEE80211_STA_CONNECTION_POLL
)
420 void ieee80211_run_deferred_scan(struct ieee80211_local
*local
)
422 lockdep_assert_held(&local
->mtx
);
424 if (!local
->scan_req
|| local
->scanning
)
427 if (!ieee80211_can_scan(local
,
428 rcu_dereference_protected(
430 lockdep_is_held(&local
->mtx
))))
433 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
,
434 round_jiffies_relative(0));
437 static void ieee80211_scan_state_send_probe(struct ieee80211_local
*local
,
438 unsigned long *next_delay
)
441 struct ieee80211_sub_if_data
*sdata
;
442 enum ieee80211_band band
= local
->hw
.conf
.chandef
.chan
->band
;
445 tx_flags
= IEEE80211_TX_INTFL_OFFCHAN_TX_OK
;
446 if (local
->scan_req
->no_cck
)
447 tx_flags
|= IEEE80211_TX_CTL_NO_CCK_RATE
;
449 sdata
= rcu_dereference_protected(local
->scan_sdata
,
450 lockdep_is_held(&local
->mtx
));
452 for (i
= 0; i
< local
->scan_req
->n_ssids
; i
++)
453 ieee80211_send_probe_req(
455 local
->scan_req
->ssids
[i
].ssid
,
456 local
->scan_req
->ssids
[i
].ssid_len
,
457 local
->scan_req
->ie
, local
->scan_req
->ie_len
,
458 local
->scan_req
->rates
[band
], false,
459 tx_flags
, local
->hw
.conf
.chandef
.chan
, true);
462 * After sending probe requests, wait for probe responses
465 *next_delay
= IEEE80211_CHANNEL_TIME
;
466 local
->next_scan_state
= SCAN_DECISION
;
469 static int __ieee80211_start_scan(struct ieee80211_sub_if_data
*sdata
,
470 struct cfg80211_scan_request
*req
)
472 struct ieee80211_local
*local
= sdata
->local
;
475 lockdep_assert_held(&local
->mtx
);
480 if (!ieee80211_can_scan(local
, sdata
)) {
481 /* wait for the work to finish/time out */
482 local
->scan_req
= req
;
483 rcu_assign_pointer(local
->scan_sdata
, sdata
);
487 if (local
->ops
->hw_scan
) {
490 local
->hw_scan_ies_bufsize
= local
->scan_ies_len
+ req
->ie_len
;
492 if (local
->hw
.flags
& IEEE80211_SINGLE_HW_SCAN_ON_ALL_BANDS
) {
494 u8 bands_counted
= 0;
496 for (i
= 0; i
< req
->n_channels
; i
++) {
497 if (bands_counted
& BIT(req
->channels
[i
]->band
))
499 bands_counted
|= BIT(req
->channels
[i
]->band
);
503 local
->hw_scan_ies_bufsize
*= n_bands
;
506 local
->hw_scan_req
= kmalloc(
507 sizeof(*local
->hw_scan_req
) +
508 req
->n_channels
* sizeof(req
->channels
[0]) +
509 local
->hw_scan_ies_bufsize
, GFP_KERNEL
);
510 if (!local
->hw_scan_req
)
513 local
->hw_scan_req
->req
.ssids
= req
->ssids
;
514 local
->hw_scan_req
->req
.n_ssids
= req
->n_ssids
;
515 ies
= (u8
*)local
->hw_scan_req
+
516 sizeof(*local
->hw_scan_req
) +
517 req
->n_channels
* sizeof(req
->channels
[0]);
518 local
->hw_scan_req
->req
.ie
= ies
;
519 local
->hw_scan_req
->req
.flags
= req
->flags
;
521 local
->hw_scan_band
= 0;
524 * After allocating local->hw_scan_req, we must
525 * go through until ieee80211_prep_hw_scan(), so
526 * anything that might be changed here and leave
527 * this function early must not go after this
532 local
->scan_req
= req
;
533 rcu_assign_pointer(local
->scan_sdata
, sdata
);
535 if (local
->ops
->hw_scan
) {
536 __set_bit(SCAN_HW_SCANNING
, &local
->scanning
);
537 } else if ((req
->n_channels
== 1) &&
538 (req
->channels
[0] == local
->_oper_chandef
.chan
)) {
540 * If we are scanning only on the operating channel
541 * then we do not need to stop normal activities
543 unsigned long next_delay
;
545 __set_bit(SCAN_ONCHANNEL_SCANNING
, &local
->scanning
);
547 ieee80211_recalc_idle(local
);
549 /* Notify driver scan is starting, keep order of operations
550 * same as normal software scan, in case that matters. */
551 drv_sw_scan_start(local
);
553 ieee80211_configure_filter(local
); /* accept probe-responses */
555 /* We need to ensure power level is at max for scanning. */
556 ieee80211_hw_config(local
, 0);
558 if ((req
->channels
[0]->flags
&
559 IEEE80211_CHAN_NO_IR
) ||
560 !local
->scan_req
->n_ssids
) {
561 next_delay
= IEEE80211_PASSIVE_CHANNEL_TIME
;
563 ieee80211_scan_state_send_probe(local
, &next_delay
);
564 next_delay
= IEEE80211_CHANNEL_TIME
;
567 /* Now, just wait a bit and we are all done! */
568 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
,
572 /* Do normal software scan */
573 __set_bit(SCAN_SW_SCANNING
, &local
->scanning
);
576 ieee80211_recalc_idle(local
);
578 if (local
->ops
->hw_scan
) {
579 WARN_ON(!ieee80211_prep_hw_scan(local
));
580 rc
= drv_hw_scan(local
, sdata
, local
->hw_scan_req
);
582 rc
= ieee80211_start_sw_scan(local
);
585 kfree(local
->hw_scan_req
);
586 local
->hw_scan_req
= NULL
;
589 ieee80211_recalc_idle(local
);
591 local
->scan_req
= NULL
;
592 RCU_INIT_POINTER(local
->scan_sdata
, NULL
);
599 ieee80211_scan_get_channel_time(struct ieee80211_channel
*chan
)
602 * TODO: channel switching also consumes quite some time,
603 * add that delay as well to get a better estimation
605 if (chan
->flags
& IEEE80211_CHAN_NO_IR
)
606 return IEEE80211_PASSIVE_CHANNEL_TIME
;
607 return IEEE80211_PROBE_DELAY
+ IEEE80211_CHANNEL_TIME
;
610 static void ieee80211_scan_state_decision(struct ieee80211_local
*local
,
611 unsigned long *next_delay
)
613 bool associated
= false;
614 bool tx_empty
= true;
616 struct ieee80211_sub_if_data
*sdata
;
617 struct ieee80211_channel
*next_chan
;
618 enum mac80211_scan_state next_scan_state
;
621 * check if at least one STA interface is associated,
622 * check if at least one STA interface has pending tx frames
623 * and grab the lowest used beacon interval
625 mutex_lock(&local
->iflist_mtx
);
626 list_for_each_entry(sdata
, &local
->interfaces
, list
) {
627 if (!ieee80211_sdata_running(sdata
))
630 if (sdata
->vif
.type
== NL80211_IFTYPE_STATION
) {
631 if (sdata
->u
.mgd
.associated
) {
634 if (!qdisc_all_tx_empty(sdata
->dev
)) {
641 mutex_unlock(&local
->iflist_mtx
);
643 next_chan
= local
->scan_req
->channels
[local
->scan_channel_idx
];
646 * we're currently scanning a different channel, let's
647 * see if we can scan another channel without interfering
648 * with the current traffic situation.
650 * Keep good latency, do not stay off-channel more than 125 ms.
653 bad_latency
= time_after(jiffies
+
654 ieee80211_scan_get_channel_time(next_chan
),
655 local
->leave_oper_channel_time
+ HZ
/ 8);
657 if (associated
&& !tx_empty
) {
658 if (local
->scan_req
->flags
& NL80211_SCAN_FLAG_LOW_PRIORITY
)
659 next_scan_state
= SCAN_ABORT
;
661 next_scan_state
= SCAN_SUSPEND
;
662 } else if (associated
&& bad_latency
) {
663 next_scan_state
= SCAN_SUSPEND
;
665 next_scan_state
= SCAN_SET_CHANNEL
;
668 local
->next_scan_state
= next_scan_state
;
673 static void ieee80211_scan_state_set_channel(struct ieee80211_local
*local
,
674 unsigned long *next_delay
)
677 struct ieee80211_channel
*chan
;
678 enum nl80211_bss_scan_width oper_scan_width
;
681 chan
= local
->scan_req
->channels
[local
->scan_channel_idx
];
683 local
->scan_chandef
.chan
= chan
;
684 local
->scan_chandef
.center_freq1
= chan
->center_freq
;
685 local
->scan_chandef
.center_freq2
= 0;
686 switch (local
->scan_req
->scan_width
) {
687 case NL80211_BSS_CHAN_WIDTH_5
:
688 local
->scan_chandef
.width
= NL80211_CHAN_WIDTH_5
;
690 case NL80211_BSS_CHAN_WIDTH_10
:
691 local
->scan_chandef
.width
= NL80211_CHAN_WIDTH_10
;
693 case NL80211_BSS_CHAN_WIDTH_20
:
694 /* If scanning on oper channel, use whatever channel-type
695 * is currently in use.
697 oper_scan_width
= cfg80211_chandef_to_scan_width(
698 &local
->_oper_chandef
);
699 if (chan
== local
->_oper_chandef
.chan
&&
700 oper_scan_width
== local
->scan_req
->scan_width
)
701 local
->scan_chandef
= local
->_oper_chandef
;
703 local
->scan_chandef
.width
= NL80211_CHAN_WIDTH_20_NOHT
;
707 if (ieee80211_hw_config(local
, IEEE80211_CONF_CHANGE_CHANNEL
))
710 /* advance state machine to next channel/band */
711 local
->scan_channel_idx
++;
714 /* if we skip this channel return to the decision state */
715 local
->next_scan_state
= SCAN_DECISION
;
720 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
721 * (which unfortunately doesn't say _why_ step a) is done,
722 * but it waits for the probe delay or until a frame is
723 * received - and the received frame would update the NAV).
724 * For now, we do not support waiting until a frame is
727 * In any case, it is not necessary for a passive scan.
729 if (chan
->flags
& IEEE80211_CHAN_NO_IR
||
730 !local
->scan_req
->n_ssids
) {
731 *next_delay
= IEEE80211_PASSIVE_CHANNEL_TIME
;
732 local
->next_scan_state
= SCAN_DECISION
;
736 /* active scan, send probes */
737 *next_delay
= IEEE80211_PROBE_DELAY
;
738 local
->next_scan_state
= SCAN_SEND_PROBE
;
741 static void ieee80211_scan_state_suspend(struct ieee80211_local
*local
,
742 unsigned long *next_delay
)
744 /* switch back to the operating channel */
745 local
->scan_chandef
.chan
= NULL
;
746 ieee80211_hw_config(local
, IEEE80211_CONF_CHANGE_CHANNEL
);
749 ieee80211_offchannel_return(local
);
751 *next_delay
= HZ
/ 5;
752 /* afterwards, resume scan & go to next channel */
753 local
->next_scan_state
= SCAN_RESUME
;
756 static void ieee80211_scan_state_resume(struct ieee80211_local
*local
,
757 unsigned long *next_delay
)
759 ieee80211_offchannel_stop_vifs(local
);
761 if (local
->ops
->flush
) {
762 ieee80211_flush_queues(local
, NULL
);
765 *next_delay
= HZ
/ 10;
767 /* remember when we left the operating channel */
768 local
->leave_oper_channel_time
= jiffies
;
770 /* advance to the next channel to be scanned */
771 local
->next_scan_state
= SCAN_SET_CHANNEL
;
774 void ieee80211_scan_work(struct work_struct
*work
)
776 struct ieee80211_local
*local
=
777 container_of(work
, struct ieee80211_local
, scan_work
.work
);
778 struct ieee80211_sub_if_data
*sdata
;
779 unsigned long next_delay
= 0;
782 mutex_lock(&local
->mtx
);
784 sdata
= rcu_dereference_protected(local
->scan_sdata
,
785 lockdep_is_held(&local
->mtx
));
787 /* When scanning on-channel, the first-callback means completed. */
788 if (test_bit(SCAN_ONCHANNEL_SCANNING
, &local
->scanning
)) {
789 aborted
= test_and_clear_bit(SCAN_ABORTED
, &local
->scanning
);
793 if (test_and_clear_bit(SCAN_COMPLETED
, &local
->scanning
)) {
794 aborted
= test_and_clear_bit(SCAN_ABORTED
, &local
->scanning
);
798 if (!sdata
|| !local
->scan_req
)
801 if (local
->scan_req
&& !local
->scanning
) {
802 struct cfg80211_scan_request
*req
= local
->scan_req
;
805 local
->scan_req
= NULL
;
806 RCU_INIT_POINTER(local
->scan_sdata
, NULL
);
808 rc
= __ieee80211_start_scan(sdata
, req
);
810 /* need to complete scan in cfg80211 */
811 local
->scan_req
= req
;
819 * as long as no delay is required advance immediately
820 * without scheduling a new work
823 if (!ieee80211_sdata_running(sdata
)) {
828 switch (local
->next_scan_state
) {
830 /* if no more bands/channels left, complete scan */
831 if (local
->scan_channel_idx
>= local
->scan_req
->n_channels
) {
835 ieee80211_scan_state_decision(local
, &next_delay
);
837 case SCAN_SET_CHANNEL
:
838 ieee80211_scan_state_set_channel(local
, &next_delay
);
840 case SCAN_SEND_PROBE
:
841 ieee80211_scan_state_send_probe(local
, &next_delay
);
844 ieee80211_scan_state_suspend(local
, &next_delay
);
847 ieee80211_scan_state_resume(local
, &next_delay
);
853 } while (next_delay
== 0);
855 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
, next_delay
);
859 __ieee80211_scan_completed(&local
->hw
, aborted
);
861 mutex_unlock(&local
->mtx
);
864 int ieee80211_request_scan(struct ieee80211_sub_if_data
*sdata
,
865 struct cfg80211_scan_request
*req
)
869 mutex_lock(&sdata
->local
->mtx
);
870 res
= __ieee80211_start_scan(sdata
, req
);
871 mutex_unlock(&sdata
->local
->mtx
);
876 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data
*sdata
,
877 const u8
*ssid
, u8 ssid_len
,
878 struct ieee80211_channel
*chan
,
879 enum nl80211_bss_scan_width scan_width
)
881 struct ieee80211_local
*local
= sdata
->local
;
883 enum ieee80211_band band
;
885 mutex_lock(&local
->mtx
);
891 /* fill internal scan request */
896 for (band
= 0; band
< IEEE80211_NUM_BANDS
; band
++) {
897 if (!local
->hw
.wiphy
->bands
[band
])
900 max_n
= local
->hw
.wiphy
->bands
[band
]->n_channels
;
901 for (i
= 0; i
< max_n
; i
++) {
902 struct ieee80211_channel
*tmp_ch
=
903 &local
->hw
.wiphy
->bands
[band
]->channels
[i
];
905 if (tmp_ch
->flags
& (IEEE80211_CHAN_NO_IR
|
906 IEEE80211_CHAN_DISABLED
))
909 local
->int_scan_req
->channels
[n_ch
] = tmp_ch
;
914 if (WARN_ON_ONCE(n_ch
== 0))
917 local
->int_scan_req
->n_channels
= n_ch
;
919 if (WARN_ON_ONCE(chan
->flags
& (IEEE80211_CHAN_NO_IR
|
920 IEEE80211_CHAN_DISABLED
)))
923 local
->int_scan_req
->channels
[0] = chan
;
924 local
->int_scan_req
->n_channels
= 1;
927 local
->int_scan_req
->ssids
= &local
->scan_ssid
;
928 local
->int_scan_req
->n_ssids
= 1;
929 local
->int_scan_req
->scan_width
= scan_width
;
930 memcpy(local
->int_scan_req
->ssids
[0].ssid
, ssid
, IEEE80211_MAX_SSID_LEN
);
931 local
->int_scan_req
->ssids
[0].ssid_len
= ssid_len
;
933 ret
= __ieee80211_start_scan(sdata
, sdata
->local
->int_scan_req
);
935 mutex_unlock(&local
->mtx
);
940 * Only call this function when a scan can't be queued -- under RTNL.
942 void ieee80211_scan_cancel(struct ieee80211_local
*local
)
945 * We are canceling software scan, or deferred scan that was not
946 * yet really started (see __ieee80211_start_scan ).
948 * Regarding hardware scan:
949 * - we can not call __ieee80211_scan_completed() as when
950 * SCAN_HW_SCANNING bit is set this function change
951 * local->hw_scan_req to operate on 5G band, what race with
952 * driver which can use local->hw_scan_req
954 * - we can not cancel scan_work since driver can schedule it
955 * by ieee80211_scan_completed(..., true) to finish scan
957 * Hence we only call the cancel_hw_scan() callback, but the low-level
958 * driver is still responsible for calling ieee80211_scan_completed()
959 * after the scan was completed/aborted.
962 mutex_lock(&local
->mtx
);
963 if (!local
->scan_req
)
967 * We have a scan running and the driver already reported completion,
968 * but the worker hasn't run yet or is stuck on the mutex - mark it as
971 if (test_bit(SCAN_HW_SCANNING
, &local
->scanning
) &&
972 test_bit(SCAN_COMPLETED
, &local
->scanning
)) {
973 set_bit(SCAN_HW_CANCELLED
, &local
->scanning
);
977 if (test_bit(SCAN_HW_SCANNING
, &local
->scanning
)) {
979 * Make sure that __ieee80211_scan_completed doesn't trigger a
980 * scan on another band.
982 set_bit(SCAN_HW_CANCELLED
, &local
->scanning
);
983 if (local
->ops
->cancel_hw_scan
)
984 drv_cancel_hw_scan(local
,
985 rcu_dereference_protected(local
->scan_sdata
,
986 lockdep_is_held(&local
->mtx
)));
991 * If the work is currently running, it must be blocked on
992 * the mutex, but we'll set scan_sdata = NULL and it'll
993 * simply exit once it acquires the mutex.
995 cancel_delayed_work(&local
->scan_work
);
997 __ieee80211_scan_completed(&local
->hw
, true);
999 mutex_unlock(&local
->mtx
);
1002 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data
*sdata
,
1003 struct cfg80211_sched_scan_request
*req
)
1005 struct ieee80211_local
*local
= sdata
->local
;
1006 struct ieee80211_sched_scan_ies sched_scan_ies
= {};
1007 struct cfg80211_chan_def chandef
;
1008 int ret
, i
, iebufsz
;
1009 struct ieee80211_scan_ies dummy_ie_desc
;
1011 iebufsz
= local
->scan_ies_len
+ req
->ie_len
;
1013 lockdep_assert_held(&local
->mtx
);
1015 if (!local
->ops
->sched_scan_start
)
1018 for (i
= 0; i
< IEEE80211_NUM_BANDS
; i
++) {
1019 u32 rate_masks
[IEEE80211_NUM_BANDS
] = {};
1021 if (!local
->hw
.wiphy
->bands
[i
])
1024 sched_scan_ies
.ie
[i
] = kzalloc(iebufsz
, GFP_KERNEL
);
1025 if (!sched_scan_ies
.ie
[i
]) {
1030 ieee80211_prepare_scan_chandef(&chandef
, req
->scan_width
);
1031 rate_masks
[i
] = (u32
) -1;
1033 sched_scan_ies
.len
[i
] =
1034 ieee80211_build_preq_ies(local
, sched_scan_ies
.ie
[i
],
1035 iebufsz
, &dummy_ie_desc
,
1036 req
->ie
, req
->ie_len
, BIT(i
),
1037 rate_masks
, &chandef
);
1040 ret
= drv_sched_scan_start(local
, sdata
, req
, &sched_scan_ies
);
1042 rcu_assign_pointer(local
->sched_scan_sdata
, sdata
);
1043 local
->sched_scan_req
= req
;
1048 kfree(sched_scan_ies
.ie
[--i
]);
1051 /* Clean in case of failure after HW restart or upon resume. */
1052 RCU_INIT_POINTER(local
->sched_scan_sdata
, NULL
);
1053 local
->sched_scan_req
= NULL
;
1059 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data
*sdata
,
1060 struct cfg80211_sched_scan_request
*req
)
1062 struct ieee80211_local
*local
= sdata
->local
;
1065 mutex_lock(&local
->mtx
);
1067 if (rcu_access_pointer(local
->sched_scan_sdata
)) {
1068 mutex_unlock(&local
->mtx
);
1072 ret
= __ieee80211_request_sched_scan_start(sdata
, req
);
1074 mutex_unlock(&local
->mtx
);
1078 int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data
*sdata
)
1080 struct ieee80211_local
*local
= sdata
->local
;
1083 mutex_lock(&local
->mtx
);
1085 if (!local
->ops
->sched_scan_stop
) {
1090 /* We don't want to restart sched scan anymore. */
1091 local
->sched_scan_req
= NULL
;
1093 if (rcu_access_pointer(local
->sched_scan_sdata
)) {
1094 ret
= drv_sched_scan_stop(local
, sdata
);
1096 rcu_assign_pointer(local
->sched_scan_sdata
, NULL
);
1099 mutex_unlock(&local
->mtx
);
1104 void ieee80211_sched_scan_results(struct ieee80211_hw
*hw
)
1106 struct ieee80211_local
*local
= hw_to_local(hw
);
1108 trace_api_sched_scan_results(local
);
1110 cfg80211_sched_scan_results(hw
->wiphy
);
1112 EXPORT_SYMBOL(ieee80211_sched_scan_results
);
1114 void ieee80211_sched_scan_end(struct ieee80211_local
*local
)
1116 mutex_lock(&local
->mtx
);
1118 if (!rcu_access_pointer(local
->sched_scan_sdata
)) {
1119 mutex_unlock(&local
->mtx
);
1123 RCU_INIT_POINTER(local
->sched_scan_sdata
, NULL
);
1125 /* If sched scan was aborted by the driver. */
1126 local
->sched_scan_req
= NULL
;
1128 mutex_unlock(&local
->mtx
);
1130 cfg80211_sched_scan_stopped(local
->hw
.wiphy
);
1133 void ieee80211_sched_scan_stopped_work(struct work_struct
*work
)
1135 struct ieee80211_local
*local
=
1136 container_of(work
, struct ieee80211_local
,
1137 sched_scan_stopped_work
);
1139 ieee80211_sched_scan_end(local
);
1142 void ieee80211_sched_scan_stopped(struct ieee80211_hw
*hw
)
1144 struct ieee80211_local
*local
= hw_to_local(hw
);
1146 trace_api_sched_scan_stopped(local
);
1148 schedule_work(&local
->sched_scan_stopped_work
);
1150 EXPORT_SYMBOL(ieee80211_sched_scan_stopped
);