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
;
238 enum ieee80211_band band
;
239 int i
, ielen
, n_chans
;
241 if (test_bit(SCAN_HW_CANCELLED
, &local
->scanning
))
245 if (local
->hw_scan_band
== IEEE80211_NUM_BANDS
)
248 band
= local
->hw_scan_band
;
250 for (i
= 0; i
< req
->n_channels
; i
++) {
251 if (req
->channels
[i
]->band
== band
) {
252 local
->hw_scan_req
->channels
[n_chans
] =
258 local
->hw_scan_band
++;
261 local
->hw_scan_req
->n_channels
= n_chans
;
262 ieee80211_prepare_scan_chandef(&chandef
, req
->scan_width
);
264 ielen
= ieee80211_build_preq_ies(local
, (u8
*)local
->hw_scan_req
->ie
,
265 local
->hw_scan_ies_bufsize
,
266 req
->ie
, req
->ie_len
, band
,
267 req
->rates
[band
], &chandef
);
268 local
->hw_scan_req
->ie_len
= ielen
;
269 local
->hw_scan_req
->no_cck
= req
->no_cck
;
274 static void __ieee80211_scan_completed(struct ieee80211_hw
*hw
, bool aborted
,
277 struct ieee80211_local
*local
= hw_to_local(hw
);
279 lockdep_assert_held(&local
->mtx
);
282 * It's ok to abort a not-yet-running scan (that
283 * we have one at all will be verified by checking
284 * local->scan_req next), but not to complete it
287 if (WARN_ON(!local
->scanning
&& !aborted
))
290 if (WARN_ON(!local
->scan_req
))
293 if (was_hw_scan
&& !aborted
&& ieee80211_prep_hw_scan(local
)) {
296 rc
= drv_hw_scan(local
,
297 rcu_dereference_protected(local
->scan_sdata
,
298 lockdep_is_held(&local
->mtx
)),
305 kfree(local
->hw_scan_req
);
306 local
->hw_scan_req
= NULL
;
308 if (local
->scan_req
!= local
->int_scan_req
)
309 cfg80211_scan_done(local
->scan_req
, aborted
);
310 local
->scan_req
= NULL
;
311 rcu_assign_pointer(local
->scan_sdata
, NULL
);
314 local
->scan_chandef
.chan
= NULL
;
316 /* Set power back to normal operating levels. */
317 ieee80211_hw_config(local
, 0);
320 ieee80211_configure_filter(local
);
321 drv_sw_scan_complete(local
);
322 ieee80211_offchannel_return(local
);
325 ieee80211_recalc_idle(local
);
327 ieee80211_mlme_notify_scan_completed(local
);
328 ieee80211_ibss_notify_scan_completed(local
);
329 ieee80211_mesh_notify_scan_completed(local
);
330 ieee80211_start_next_roc(local
);
333 void ieee80211_scan_completed(struct ieee80211_hw
*hw
, bool aborted
)
335 struct ieee80211_local
*local
= hw_to_local(hw
);
337 trace_api_scan_completed(local
, aborted
);
339 set_bit(SCAN_COMPLETED
, &local
->scanning
);
341 set_bit(SCAN_ABORTED
, &local
->scanning
);
342 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
, 0);
344 EXPORT_SYMBOL(ieee80211_scan_completed
);
346 static int ieee80211_start_sw_scan(struct ieee80211_local
*local
)
348 /* Software scan is not supported in multi-channel cases */
349 if (local
->use_chanctx
)
353 * Hardware/driver doesn't support hw_scan, so use software
354 * scanning instead. First send a nullfunc frame with power save
355 * bit on so that AP will buffer the frames for us while we are not
356 * listening, then send probe requests to each channel and wait for
357 * the responses. After all channels are scanned, tune back to the
358 * original channel and send a nullfunc frame with power save bit
359 * off to trigger the AP to send us all the buffered frames.
361 * Note that while local->sw_scanning is true everything else but
362 * nullfunc frames and probe requests will be dropped in
363 * ieee80211_tx_h_check_assoc().
365 drv_sw_scan_start(local
);
367 local
->leave_oper_channel_time
= jiffies
;
368 local
->next_scan_state
= SCAN_DECISION
;
369 local
->scan_channel_idx
= 0;
371 ieee80211_offchannel_stop_vifs(local
);
373 /* ensure nullfunc is transmitted before leaving operating channel */
374 ieee80211_flush_queues(local
, NULL
);
376 ieee80211_configure_filter(local
);
378 /* We need to set power level at maximum rate for scanning. */
379 ieee80211_hw_config(local
, 0);
381 ieee80211_queue_delayed_work(&local
->hw
,
382 &local
->scan_work
, 0);
387 static bool ieee80211_can_scan(struct ieee80211_local
*local
,
388 struct ieee80211_sub_if_data
*sdata
)
390 if (local
->radar_detect_enabled
)
393 if (!list_empty(&local
->roc_list
))
396 if (sdata
->vif
.type
== NL80211_IFTYPE_STATION
&&
397 sdata
->u
.mgd
.flags
& IEEE80211_STA_CONNECTION_POLL
)
403 void ieee80211_run_deferred_scan(struct ieee80211_local
*local
)
405 lockdep_assert_held(&local
->mtx
);
407 if (!local
->scan_req
|| local
->scanning
)
410 if (!ieee80211_can_scan(local
,
411 rcu_dereference_protected(
413 lockdep_is_held(&local
->mtx
))))
416 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
,
417 round_jiffies_relative(0));
420 static void ieee80211_scan_state_send_probe(struct ieee80211_local
*local
,
421 unsigned long *next_delay
)
424 struct ieee80211_sub_if_data
*sdata
;
425 enum ieee80211_band band
= local
->hw
.conf
.chandef
.chan
->band
;
428 tx_flags
= IEEE80211_TX_INTFL_OFFCHAN_TX_OK
;
429 if (local
->scan_req
->no_cck
)
430 tx_flags
|= IEEE80211_TX_CTL_NO_CCK_RATE
;
432 sdata
= rcu_dereference_protected(local
->scan_sdata
,
433 lockdep_is_held(&local
->mtx
));
435 for (i
= 0; i
< local
->scan_req
->n_ssids
; i
++)
436 ieee80211_send_probe_req(
438 local
->scan_req
->ssids
[i
].ssid
,
439 local
->scan_req
->ssids
[i
].ssid_len
,
440 local
->scan_req
->ie
, local
->scan_req
->ie_len
,
441 local
->scan_req
->rates
[band
], false,
442 tx_flags
, local
->hw
.conf
.chandef
.chan
, true);
445 * After sending probe requests, wait for probe responses
448 *next_delay
= IEEE80211_CHANNEL_TIME
;
449 local
->next_scan_state
= SCAN_DECISION
;
452 static int __ieee80211_start_scan(struct ieee80211_sub_if_data
*sdata
,
453 struct cfg80211_scan_request
*req
)
455 struct ieee80211_local
*local
= sdata
->local
;
458 lockdep_assert_held(&local
->mtx
);
463 if (!ieee80211_can_scan(local
, sdata
)) {
464 /* wait for the work to finish/time out */
465 local
->scan_req
= req
;
466 rcu_assign_pointer(local
->scan_sdata
, sdata
);
470 if (local
->ops
->hw_scan
) {
473 local
->hw_scan_ies_bufsize
= 2 + IEEE80211_MAX_SSID_LEN
+
474 local
->scan_ies_len
+
476 local
->hw_scan_req
= kmalloc(
477 sizeof(*local
->hw_scan_req
) +
478 req
->n_channels
* sizeof(req
->channels
[0]) +
479 local
->hw_scan_ies_bufsize
, GFP_KERNEL
);
480 if (!local
->hw_scan_req
)
483 local
->hw_scan_req
->ssids
= req
->ssids
;
484 local
->hw_scan_req
->n_ssids
= req
->n_ssids
;
485 ies
= (u8
*)local
->hw_scan_req
+
486 sizeof(*local
->hw_scan_req
) +
487 req
->n_channels
* sizeof(req
->channels
[0]);
488 local
->hw_scan_req
->ie
= ies
;
489 local
->hw_scan_req
->flags
= req
->flags
;
491 local
->hw_scan_band
= 0;
494 * After allocating local->hw_scan_req, we must
495 * go through until ieee80211_prep_hw_scan(), so
496 * anything that might be changed here and leave
497 * this function early must not go after this
502 local
->scan_req
= req
;
503 rcu_assign_pointer(local
->scan_sdata
, sdata
);
505 if (local
->ops
->hw_scan
) {
506 __set_bit(SCAN_HW_SCANNING
, &local
->scanning
);
507 } else if ((req
->n_channels
== 1) &&
508 (req
->channels
[0] == local
->_oper_chandef
.chan
)) {
510 * If we are scanning only on the operating channel
511 * then we do not need to stop normal activities
513 unsigned long next_delay
;
515 __set_bit(SCAN_ONCHANNEL_SCANNING
, &local
->scanning
);
517 ieee80211_recalc_idle(local
);
519 /* Notify driver scan is starting, keep order of operations
520 * same as normal software scan, in case that matters. */
521 drv_sw_scan_start(local
);
523 ieee80211_configure_filter(local
); /* accept probe-responses */
525 /* We need to ensure power level is at max for scanning. */
526 ieee80211_hw_config(local
, 0);
528 if ((req
->channels
[0]->flags
&
529 IEEE80211_CHAN_PASSIVE_SCAN
) ||
530 !local
->scan_req
->n_ssids
) {
531 next_delay
= IEEE80211_PASSIVE_CHANNEL_TIME
;
533 ieee80211_scan_state_send_probe(local
, &next_delay
);
534 next_delay
= IEEE80211_CHANNEL_TIME
;
537 /* Now, just wait a bit and we are all done! */
538 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
,
542 /* Do normal software scan */
543 __set_bit(SCAN_SW_SCANNING
, &local
->scanning
);
546 ieee80211_recalc_idle(local
);
548 if (local
->ops
->hw_scan
) {
549 WARN_ON(!ieee80211_prep_hw_scan(local
));
550 rc
= drv_hw_scan(local
, sdata
, local
->hw_scan_req
);
552 rc
= ieee80211_start_sw_scan(local
);
555 kfree(local
->hw_scan_req
);
556 local
->hw_scan_req
= NULL
;
559 ieee80211_recalc_idle(local
);
561 local
->scan_req
= NULL
;
562 rcu_assign_pointer(local
->scan_sdata
, NULL
);
569 ieee80211_scan_get_channel_time(struct ieee80211_channel
*chan
)
572 * TODO: channel switching also consumes quite some time,
573 * add that delay as well to get a better estimation
575 if (chan
->flags
& IEEE80211_CHAN_PASSIVE_SCAN
)
576 return IEEE80211_PASSIVE_CHANNEL_TIME
;
577 return IEEE80211_PROBE_DELAY
+ IEEE80211_CHANNEL_TIME
;
580 static void ieee80211_scan_state_decision(struct ieee80211_local
*local
,
581 unsigned long *next_delay
)
583 bool associated
= false;
584 bool tx_empty
= true;
586 struct ieee80211_sub_if_data
*sdata
;
587 struct ieee80211_channel
*next_chan
;
588 enum mac80211_scan_state next_scan_state
;
591 * check if at least one STA interface is associated,
592 * check if at least one STA interface has pending tx frames
593 * and grab the lowest used beacon interval
595 mutex_lock(&local
->iflist_mtx
);
596 list_for_each_entry(sdata
, &local
->interfaces
, list
) {
597 if (!ieee80211_sdata_running(sdata
))
600 if (sdata
->vif
.type
== NL80211_IFTYPE_STATION
) {
601 if (sdata
->u
.mgd
.associated
) {
604 if (!qdisc_all_tx_empty(sdata
->dev
)) {
611 mutex_unlock(&local
->iflist_mtx
);
613 next_chan
= local
->scan_req
->channels
[local
->scan_channel_idx
];
616 * we're currently scanning a different channel, let's
617 * see if we can scan another channel without interfering
618 * with the current traffic situation.
620 * Keep good latency, do not stay off-channel more than 125 ms.
623 bad_latency
= time_after(jiffies
+
624 ieee80211_scan_get_channel_time(next_chan
),
625 local
->leave_oper_channel_time
+ HZ
/ 8);
627 if (associated
&& !tx_empty
) {
628 if (local
->scan_req
->flags
& NL80211_SCAN_FLAG_LOW_PRIORITY
)
629 next_scan_state
= SCAN_ABORT
;
631 next_scan_state
= SCAN_SUSPEND
;
632 } else if (associated
&& bad_latency
) {
633 next_scan_state
= SCAN_SUSPEND
;
635 next_scan_state
= SCAN_SET_CHANNEL
;
638 local
->next_scan_state
= next_scan_state
;
643 static void ieee80211_scan_state_set_channel(struct ieee80211_local
*local
,
644 unsigned long *next_delay
)
647 struct ieee80211_channel
*chan
;
648 enum nl80211_bss_scan_width oper_scan_width
;
651 chan
= local
->scan_req
->channels
[local
->scan_channel_idx
];
653 local
->scan_chandef
.chan
= chan
;
654 local
->scan_chandef
.center_freq1
= chan
->center_freq
;
655 local
->scan_chandef
.center_freq2
= 0;
656 switch (local
->scan_req
->scan_width
) {
657 case NL80211_BSS_CHAN_WIDTH_5
:
658 local
->scan_chandef
.width
= NL80211_CHAN_WIDTH_5
;
660 case NL80211_BSS_CHAN_WIDTH_10
:
661 local
->scan_chandef
.width
= NL80211_CHAN_WIDTH_10
;
663 case NL80211_BSS_CHAN_WIDTH_20
:
664 /* If scanning on oper channel, use whatever channel-type
665 * is currently in use.
667 oper_scan_width
= cfg80211_chandef_to_scan_width(
668 &local
->_oper_chandef
);
669 if (chan
== local
->_oper_chandef
.chan
&&
670 oper_scan_width
== local
->scan_req
->scan_width
)
671 local
->scan_chandef
= local
->_oper_chandef
;
673 local
->scan_chandef
.width
= NL80211_CHAN_WIDTH_20_NOHT
;
677 if (ieee80211_hw_config(local
, IEEE80211_CONF_CHANGE_CHANNEL
))
680 /* advance state machine to next channel/band */
681 local
->scan_channel_idx
++;
684 /* if we skip this channel return to the decision state */
685 local
->next_scan_state
= SCAN_DECISION
;
690 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
691 * (which unfortunately doesn't say _why_ step a) is done,
692 * but it waits for the probe delay or until a frame is
693 * received - and the received frame would update the NAV).
694 * For now, we do not support waiting until a frame is
697 * In any case, it is not necessary for a passive scan.
699 if (chan
->flags
& IEEE80211_CHAN_PASSIVE_SCAN
||
700 !local
->scan_req
->n_ssids
) {
701 *next_delay
= IEEE80211_PASSIVE_CHANNEL_TIME
;
702 local
->next_scan_state
= SCAN_DECISION
;
706 /* active scan, send probes */
707 *next_delay
= IEEE80211_PROBE_DELAY
;
708 local
->next_scan_state
= SCAN_SEND_PROBE
;
711 static void ieee80211_scan_state_suspend(struct ieee80211_local
*local
,
712 unsigned long *next_delay
)
714 /* switch back to the operating channel */
715 local
->scan_chandef
.chan
= NULL
;
716 ieee80211_hw_config(local
, IEEE80211_CONF_CHANGE_CHANNEL
);
719 ieee80211_offchannel_return(local
);
721 *next_delay
= HZ
/ 5;
722 /* afterwards, resume scan & go to next channel */
723 local
->next_scan_state
= SCAN_RESUME
;
726 static void ieee80211_scan_state_resume(struct ieee80211_local
*local
,
727 unsigned long *next_delay
)
729 ieee80211_offchannel_stop_vifs(local
);
731 if (local
->ops
->flush
) {
732 ieee80211_flush_queues(local
, NULL
);
735 *next_delay
= HZ
/ 10;
737 /* remember when we left the operating channel */
738 local
->leave_oper_channel_time
= jiffies
;
740 /* advance to the next channel to be scanned */
741 local
->next_scan_state
= SCAN_SET_CHANNEL
;
744 void ieee80211_scan_work(struct work_struct
*work
)
746 struct ieee80211_local
*local
=
747 container_of(work
, struct ieee80211_local
, scan_work
.work
);
748 struct ieee80211_sub_if_data
*sdata
;
749 unsigned long next_delay
= 0;
750 bool aborted
, hw_scan
;
752 mutex_lock(&local
->mtx
);
754 sdata
= rcu_dereference_protected(local
->scan_sdata
,
755 lockdep_is_held(&local
->mtx
));
757 /* When scanning on-channel, the first-callback means completed. */
758 if (test_bit(SCAN_ONCHANNEL_SCANNING
, &local
->scanning
)) {
759 aborted
= test_and_clear_bit(SCAN_ABORTED
, &local
->scanning
);
763 if (test_and_clear_bit(SCAN_COMPLETED
, &local
->scanning
)) {
764 aborted
= test_and_clear_bit(SCAN_ABORTED
, &local
->scanning
);
768 if (!sdata
|| !local
->scan_req
)
771 if (local
->scan_req
&& !local
->scanning
) {
772 struct cfg80211_scan_request
*req
= local
->scan_req
;
775 local
->scan_req
= NULL
;
776 rcu_assign_pointer(local
->scan_sdata
, NULL
);
778 rc
= __ieee80211_start_scan(sdata
, req
);
780 /* need to complete scan in cfg80211 */
781 local
->scan_req
= req
;
789 * Avoid re-scheduling when the sdata is going away.
791 if (!ieee80211_sdata_running(sdata
)) {
797 * as long as no delay is required advance immediately
798 * without scheduling a new work
801 if (!ieee80211_sdata_running(sdata
)) {
806 switch (local
->next_scan_state
) {
808 /* if no more bands/channels left, complete scan */
809 if (local
->scan_channel_idx
>= local
->scan_req
->n_channels
) {
813 ieee80211_scan_state_decision(local
, &next_delay
);
815 case SCAN_SET_CHANNEL
:
816 ieee80211_scan_state_set_channel(local
, &next_delay
);
818 case SCAN_SEND_PROBE
:
819 ieee80211_scan_state_send_probe(local
, &next_delay
);
822 ieee80211_scan_state_suspend(local
, &next_delay
);
825 ieee80211_scan_state_resume(local
, &next_delay
);
831 } while (next_delay
== 0);
833 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
, next_delay
);
837 hw_scan
= test_bit(SCAN_HW_SCANNING
, &local
->scanning
);
838 __ieee80211_scan_completed(&local
->hw
, aborted
, hw_scan
);
840 mutex_unlock(&local
->mtx
);
843 int ieee80211_request_scan(struct ieee80211_sub_if_data
*sdata
,
844 struct cfg80211_scan_request
*req
)
848 mutex_lock(&sdata
->local
->mtx
);
849 res
= __ieee80211_start_scan(sdata
, req
);
850 mutex_unlock(&sdata
->local
->mtx
);
855 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data
*sdata
,
856 const u8
*ssid
, u8 ssid_len
,
857 struct ieee80211_channel
*chan
,
858 enum nl80211_bss_scan_width scan_width
)
860 struct ieee80211_local
*local
= sdata
->local
;
862 enum ieee80211_band band
;
864 mutex_lock(&local
->mtx
);
870 /* fill internal scan request */
875 for (band
= 0; band
< IEEE80211_NUM_BANDS
; band
++) {
876 if (!local
->hw
.wiphy
->bands
[band
])
879 max_n
= local
->hw
.wiphy
->bands
[band
]->n_channels
;
880 for (i
= 0; i
< max_n
; i
++) {
881 struct ieee80211_channel
*tmp_ch
=
882 &local
->hw
.wiphy
->bands
[band
]->channels
[i
];
884 if (tmp_ch
->flags
& (IEEE80211_CHAN_NO_IBSS
|
885 IEEE80211_CHAN_DISABLED
))
888 local
->int_scan_req
->channels
[n_ch
] = tmp_ch
;
893 if (WARN_ON_ONCE(n_ch
== 0))
896 local
->int_scan_req
->n_channels
= n_ch
;
898 if (WARN_ON_ONCE(chan
->flags
& (IEEE80211_CHAN_NO_IBSS
|
899 IEEE80211_CHAN_DISABLED
)))
902 local
->int_scan_req
->channels
[0] = chan
;
903 local
->int_scan_req
->n_channels
= 1;
906 local
->int_scan_req
->ssids
= &local
->scan_ssid
;
907 local
->int_scan_req
->n_ssids
= 1;
908 local
->int_scan_req
->scan_width
= scan_width
;
909 memcpy(local
->int_scan_req
->ssids
[0].ssid
, ssid
, IEEE80211_MAX_SSID_LEN
);
910 local
->int_scan_req
->ssids
[0].ssid_len
= ssid_len
;
912 ret
= __ieee80211_start_scan(sdata
, sdata
->local
->int_scan_req
);
914 mutex_unlock(&local
->mtx
);
919 * Only call this function when a scan can't be queued -- under RTNL.
921 void ieee80211_scan_cancel(struct ieee80211_local
*local
)
924 * We are canceling software scan, or deferred scan that was not
925 * yet really started (see __ieee80211_start_scan ).
927 * Regarding hardware scan:
928 * - we can not call __ieee80211_scan_completed() as when
929 * SCAN_HW_SCANNING bit is set this function change
930 * local->hw_scan_req to operate on 5G band, what race with
931 * driver which can use local->hw_scan_req
933 * - we can not cancel scan_work since driver can schedule it
934 * by ieee80211_scan_completed(..., true) to finish scan
936 * Hence we only call the cancel_hw_scan() callback, but the low-level
937 * driver is still responsible for calling ieee80211_scan_completed()
938 * after the scan was completed/aborted.
941 mutex_lock(&local
->mtx
);
942 if (!local
->scan_req
)
946 * We have a scan running and the driver already reported completion,
947 * but the worker hasn't run yet or is stuck on the mutex - mark it as
950 if (test_bit(SCAN_HW_SCANNING
, &local
->scanning
) &&
951 test_bit(SCAN_COMPLETED
, &local
->scanning
)) {
952 set_bit(SCAN_HW_CANCELLED
, &local
->scanning
);
956 if (test_bit(SCAN_HW_SCANNING
, &local
->scanning
)) {
958 * Make sure that __ieee80211_scan_completed doesn't trigger a
959 * scan on another band.
961 set_bit(SCAN_HW_CANCELLED
, &local
->scanning
);
962 if (local
->ops
->cancel_hw_scan
)
963 drv_cancel_hw_scan(local
,
964 rcu_dereference_protected(local
->scan_sdata
,
965 lockdep_is_held(&local
->mtx
)));
970 * If the work is currently running, it must be blocked on
971 * the mutex, but we'll set scan_sdata = NULL and it'll
972 * simply exit once it acquires the mutex.
974 cancel_delayed_work(&local
->scan_work
);
976 __ieee80211_scan_completed(&local
->hw
, true, false);
978 mutex_unlock(&local
->mtx
);
981 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data
*sdata
,
982 struct cfg80211_sched_scan_request
*req
)
984 struct ieee80211_local
*local
= sdata
->local
;
985 struct ieee80211_sched_scan_ies sched_scan_ies
= {};
986 struct cfg80211_chan_def chandef
;
989 iebufsz
= 2 + IEEE80211_MAX_SSID_LEN
+
990 local
->scan_ies_len
+ req
->ie_len
;
992 mutex_lock(&local
->mtx
);
994 if (rcu_access_pointer(local
->sched_scan_sdata
)) {
999 if (!local
->ops
->sched_scan_start
) {
1004 for (i
= 0; i
< IEEE80211_NUM_BANDS
; i
++) {
1005 if (!local
->hw
.wiphy
->bands
[i
])
1008 sched_scan_ies
.ie
[i
] = kzalloc(iebufsz
, GFP_KERNEL
);
1009 if (!sched_scan_ies
.ie
[i
]) {
1014 ieee80211_prepare_scan_chandef(&chandef
, req
->scan_width
);
1016 sched_scan_ies
.len
[i
] =
1017 ieee80211_build_preq_ies(local
, sched_scan_ies
.ie
[i
],
1018 iebufsz
, req
->ie
, req
->ie_len
,
1019 i
, (u32
) -1, &chandef
);
1022 ret
= drv_sched_scan_start(local
, sdata
, req
, &sched_scan_ies
);
1024 rcu_assign_pointer(local
->sched_scan_sdata
, sdata
);
1028 kfree(sched_scan_ies
.ie
[--i
]);
1030 mutex_unlock(&local
->mtx
);
1034 int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data
*sdata
)
1036 struct ieee80211_local
*local
= sdata
->local
;
1039 mutex_lock(&local
->mtx
);
1041 if (!local
->ops
->sched_scan_stop
) {
1046 if (rcu_access_pointer(local
->sched_scan_sdata
))
1047 drv_sched_scan_stop(local
, sdata
);
1050 mutex_unlock(&local
->mtx
);
1055 void ieee80211_sched_scan_results(struct ieee80211_hw
*hw
)
1057 struct ieee80211_local
*local
= hw_to_local(hw
);
1059 trace_api_sched_scan_results(local
);
1061 cfg80211_sched_scan_results(hw
->wiphy
);
1063 EXPORT_SYMBOL(ieee80211_sched_scan_results
);
1065 void ieee80211_sched_scan_stopped_work(struct work_struct
*work
)
1067 struct ieee80211_local
*local
=
1068 container_of(work
, struct ieee80211_local
,
1069 sched_scan_stopped_work
);
1071 mutex_lock(&local
->mtx
);
1073 if (!rcu_access_pointer(local
->sched_scan_sdata
)) {
1074 mutex_unlock(&local
->mtx
);
1078 rcu_assign_pointer(local
->sched_scan_sdata
, NULL
);
1080 mutex_unlock(&local
->mtx
);
1082 cfg80211_sched_scan_stopped(local
->hw
.wiphy
);
1085 void ieee80211_sched_scan_stopped(struct ieee80211_hw
*hw
)
1087 struct ieee80211_local
*local
= hw_to_local(hw
);
1089 trace_api_sched_scan_stopped(local
);
1091 schedule_work(&local
->sched_scan_stopped_work
);
1093 EXPORT_SYMBOL(ieee80211_sched_scan_stopped
);