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_BEACON_POLL
|
398 IEEE80211_STA_CONNECTION_POLL
))
404 void ieee80211_run_deferred_scan(struct ieee80211_local
*local
)
406 lockdep_assert_held(&local
->mtx
);
408 if (!local
->scan_req
|| local
->scanning
)
411 if (!ieee80211_can_scan(local
,
412 rcu_dereference_protected(
414 lockdep_is_held(&local
->mtx
))))
417 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
,
418 round_jiffies_relative(0));
421 static void ieee80211_scan_state_send_probe(struct ieee80211_local
*local
,
422 unsigned long *next_delay
)
425 struct ieee80211_sub_if_data
*sdata
;
426 enum ieee80211_band band
= local
->hw
.conf
.chandef
.chan
->band
;
429 tx_flags
= IEEE80211_TX_INTFL_OFFCHAN_TX_OK
;
430 if (local
->scan_req
->no_cck
)
431 tx_flags
|= IEEE80211_TX_CTL_NO_CCK_RATE
;
433 sdata
= rcu_dereference_protected(local
->scan_sdata
,
434 lockdep_is_held(&local
->mtx
));
436 for (i
= 0; i
< local
->scan_req
->n_ssids
; i
++)
437 ieee80211_send_probe_req(
439 local
->scan_req
->ssids
[i
].ssid
,
440 local
->scan_req
->ssids
[i
].ssid_len
,
441 local
->scan_req
->ie
, local
->scan_req
->ie_len
,
442 local
->scan_req
->rates
[band
], false,
443 tx_flags
, local
->hw
.conf
.chandef
.chan
, true);
446 * After sending probe requests, wait for probe responses
449 *next_delay
= IEEE80211_CHANNEL_TIME
;
450 local
->next_scan_state
= SCAN_DECISION
;
453 static int __ieee80211_start_scan(struct ieee80211_sub_if_data
*sdata
,
454 struct cfg80211_scan_request
*req
)
456 struct ieee80211_local
*local
= sdata
->local
;
459 lockdep_assert_held(&local
->mtx
);
464 if (!ieee80211_can_scan(local
, sdata
)) {
465 /* wait for the work to finish/time out */
466 local
->scan_req
= req
;
467 rcu_assign_pointer(local
->scan_sdata
, sdata
);
471 if (local
->ops
->hw_scan
) {
474 local
->hw_scan_ies_bufsize
= 2 + IEEE80211_MAX_SSID_LEN
+
475 local
->scan_ies_len
+
477 local
->hw_scan_req
= kmalloc(
478 sizeof(*local
->hw_scan_req
) +
479 req
->n_channels
* sizeof(req
->channels
[0]) +
480 local
->hw_scan_ies_bufsize
, GFP_KERNEL
);
481 if (!local
->hw_scan_req
)
484 local
->hw_scan_req
->ssids
= req
->ssids
;
485 local
->hw_scan_req
->n_ssids
= req
->n_ssids
;
486 ies
= (u8
*)local
->hw_scan_req
+
487 sizeof(*local
->hw_scan_req
) +
488 req
->n_channels
* sizeof(req
->channels
[0]);
489 local
->hw_scan_req
->ie
= ies
;
490 local
->hw_scan_req
->flags
= req
->flags
;
492 local
->hw_scan_band
= 0;
495 * After allocating local->hw_scan_req, we must
496 * go through until ieee80211_prep_hw_scan(), so
497 * anything that might be changed here and leave
498 * this function early must not go after this
503 local
->scan_req
= req
;
504 rcu_assign_pointer(local
->scan_sdata
, sdata
);
506 if (local
->ops
->hw_scan
) {
507 __set_bit(SCAN_HW_SCANNING
, &local
->scanning
);
508 } else if ((req
->n_channels
== 1) &&
509 (req
->channels
[0] == local
->_oper_chandef
.chan
)) {
511 * If we are scanning only on the operating channel
512 * then we do not need to stop normal activities
514 unsigned long next_delay
;
516 __set_bit(SCAN_ONCHANNEL_SCANNING
, &local
->scanning
);
518 ieee80211_recalc_idle(local
);
520 /* Notify driver scan is starting, keep order of operations
521 * same as normal software scan, in case that matters. */
522 drv_sw_scan_start(local
);
524 ieee80211_configure_filter(local
); /* accept probe-responses */
526 /* We need to ensure power level is at max for scanning. */
527 ieee80211_hw_config(local
, 0);
529 if ((req
->channels
[0]->flags
&
530 IEEE80211_CHAN_PASSIVE_SCAN
) ||
531 !local
->scan_req
->n_ssids
) {
532 next_delay
= IEEE80211_PASSIVE_CHANNEL_TIME
;
534 ieee80211_scan_state_send_probe(local
, &next_delay
);
535 next_delay
= IEEE80211_CHANNEL_TIME
;
538 /* Now, just wait a bit and we are all done! */
539 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
,
543 /* Do normal software scan */
544 __set_bit(SCAN_SW_SCANNING
, &local
->scanning
);
547 ieee80211_recalc_idle(local
);
549 if (local
->ops
->hw_scan
) {
550 WARN_ON(!ieee80211_prep_hw_scan(local
));
551 rc
= drv_hw_scan(local
, sdata
, local
->hw_scan_req
);
553 rc
= ieee80211_start_sw_scan(local
);
556 kfree(local
->hw_scan_req
);
557 local
->hw_scan_req
= NULL
;
560 ieee80211_recalc_idle(local
);
562 local
->scan_req
= NULL
;
563 rcu_assign_pointer(local
->scan_sdata
, NULL
);
570 ieee80211_scan_get_channel_time(struct ieee80211_channel
*chan
)
573 * TODO: channel switching also consumes quite some time,
574 * add that delay as well to get a better estimation
576 if (chan
->flags
& IEEE80211_CHAN_PASSIVE_SCAN
)
577 return IEEE80211_PASSIVE_CHANNEL_TIME
;
578 return IEEE80211_PROBE_DELAY
+ IEEE80211_CHANNEL_TIME
;
581 static void ieee80211_scan_state_decision(struct ieee80211_local
*local
,
582 unsigned long *next_delay
)
584 bool associated
= false;
585 bool tx_empty
= true;
587 struct ieee80211_sub_if_data
*sdata
;
588 struct ieee80211_channel
*next_chan
;
589 enum mac80211_scan_state next_scan_state
;
592 * check if at least one STA interface is associated,
593 * check if at least one STA interface has pending tx frames
594 * and grab the lowest used beacon interval
596 mutex_lock(&local
->iflist_mtx
);
597 list_for_each_entry(sdata
, &local
->interfaces
, list
) {
598 if (!ieee80211_sdata_running(sdata
))
601 if (sdata
->vif
.type
== NL80211_IFTYPE_STATION
) {
602 if (sdata
->u
.mgd
.associated
) {
605 if (!qdisc_all_tx_empty(sdata
->dev
)) {
612 mutex_unlock(&local
->iflist_mtx
);
614 next_chan
= local
->scan_req
->channels
[local
->scan_channel_idx
];
617 * we're currently scanning a different channel, let's
618 * see if we can scan another channel without interfering
619 * with the current traffic situation.
621 * Keep good latency, do not stay off-channel more than 125 ms.
624 bad_latency
= time_after(jiffies
+
625 ieee80211_scan_get_channel_time(next_chan
),
626 local
->leave_oper_channel_time
+ HZ
/ 8);
628 if (associated
&& !tx_empty
) {
629 if (local
->scan_req
->flags
& NL80211_SCAN_FLAG_LOW_PRIORITY
)
630 next_scan_state
= SCAN_ABORT
;
632 next_scan_state
= SCAN_SUSPEND
;
633 } else if (associated
&& bad_latency
) {
634 next_scan_state
= SCAN_SUSPEND
;
636 next_scan_state
= SCAN_SET_CHANNEL
;
639 local
->next_scan_state
= next_scan_state
;
644 static void ieee80211_scan_state_set_channel(struct ieee80211_local
*local
,
645 unsigned long *next_delay
)
648 struct ieee80211_channel
*chan
;
649 enum nl80211_bss_scan_width oper_scan_width
;
652 chan
= local
->scan_req
->channels
[local
->scan_channel_idx
];
654 local
->scan_chandef
.chan
= chan
;
655 local
->scan_chandef
.center_freq1
= chan
->center_freq
;
656 local
->scan_chandef
.center_freq2
= 0;
657 switch (local
->scan_req
->scan_width
) {
658 case NL80211_BSS_CHAN_WIDTH_5
:
659 local
->scan_chandef
.width
= NL80211_CHAN_WIDTH_5
;
661 case NL80211_BSS_CHAN_WIDTH_10
:
662 local
->scan_chandef
.width
= NL80211_CHAN_WIDTH_10
;
664 case NL80211_BSS_CHAN_WIDTH_20
:
665 /* If scanning on oper channel, use whatever channel-type
666 * is currently in use.
668 oper_scan_width
= cfg80211_chandef_to_scan_width(
669 &local
->_oper_chandef
);
670 if (chan
== local
->_oper_chandef
.chan
&&
671 oper_scan_width
== local
->scan_req
->scan_width
)
672 local
->scan_chandef
= local
->_oper_chandef
;
674 local
->scan_chandef
.width
= NL80211_CHAN_WIDTH_20_NOHT
;
678 if (ieee80211_hw_config(local
, IEEE80211_CONF_CHANGE_CHANNEL
))
681 /* advance state machine to next channel/band */
682 local
->scan_channel_idx
++;
685 /* if we skip this channel return to the decision state */
686 local
->next_scan_state
= SCAN_DECISION
;
691 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
692 * (which unfortunately doesn't say _why_ step a) is done,
693 * but it waits for the probe delay or until a frame is
694 * received - and the received frame would update the NAV).
695 * For now, we do not support waiting until a frame is
698 * In any case, it is not necessary for a passive scan.
700 if (chan
->flags
& IEEE80211_CHAN_PASSIVE_SCAN
||
701 !local
->scan_req
->n_ssids
) {
702 *next_delay
= IEEE80211_PASSIVE_CHANNEL_TIME
;
703 local
->next_scan_state
= SCAN_DECISION
;
707 /* active scan, send probes */
708 *next_delay
= IEEE80211_PROBE_DELAY
;
709 local
->next_scan_state
= SCAN_SEND_PROBE
;
712 static void ieee80211_scan_state_suspend(struct ieee80211_local
*local
,
713 unsigned long *next_delay
)
715 /* switch back to the operating channel */
716 local
->scan_chandef
.chan
= NULL
;
717 ieee80211_hw_config(local
, IEEE80211_CONF_CHANGE_CHANNEL
);
720 ieee80211_offchannel_return(local
);
722 *next_delay
= HZ
/ 5;
723 /* afterwards, resume scan & go to next channel */
724 local
->next_scan_state
= SCAN_RESUME
;
727 static void ieee80211_scan_state_resume(struct ieee80211_local
*local
,
728 unsigned long *next_delay
)
730 ieee80211_offchannel_stop_vifs(local
);
732 if (local
->ops
->flush
) {
733 ieee80211_flush_queues(local
, NULL
);
736 *next_delay
= HZ
/ 10;
738 /* remember when we left the operating channel */
739 local
->leave_oper_channel_time
= jiffies
;
741 /* advance to the next channel to be scanned */
742 local
->next_scan_state
= SCAN_SET_CHANNEL
;
745 void ieee80211_scan_work(struct work_struct
*work
)
747 struct ieee80211_local
*local
=
748 container_of(work
, struct ieee80211_local
, scan_work
.work
);
749 struct ieee80211_sub_if_data
*sdata
;
750 unsigned long next_delay
= 0;
751 bool aborted
, hw_scan
;
753 mutex_lock(&local
->mtx
);
755 sdata
= rcu_dereference_protected(local
->scan_sdata
,
756 lockdep_is_held(&local
->mtx
));
758 /* When scanning on-channel, the first-callback means completed. */
759 if (test_bit(SCAN_ONCHANNEL_SCANNING
, &local
->scanning
)) {
760 aborted
= test_and_clear_bit(SCAN_ABORTED
, &local
->scanning
);
764 if (test_and_clear_bit(SCAN_COMPLETED
, &local
->scanning
)) {
765 aborted
= test_and_clear_bit(SCAN_ABORTED
, &local
->scanning
);
769 if (!sdata
|| !local
->scan_req
)
772 if (local
->scan_req
&& !local
->scanning
) {
773 struct cfg80211_scan_request
*req
= local
->scan_req
;
776 local
->scan_req
= NULL
;
777 rcu_assign_pointer(local
->scan_sdata
, NULL
);
779 rc
= __ieee80211_start_scan(sdata
, req
);
781 /* need to complete scan in cfg80211 */
782 local
->scan_req
= req
;
790 * Avoid re-scheduling when the sdata is going away.
792 if (!ieee80211_sdata_running(sdata
)) {
798 * as long as no delay is required advance immediately
799 * without scheduling a new work
802 if (!ieee80211_sdata_running(sdata
)) {
807 switch (local
->next_scan_state
) {
809 /* if no more bands/channels left, complete scan */
810 if (local
->scan_channel_idx
>= local
->scan_req
->n_channels
) {
814 ieee80211_scan_state_decision(local
, &next_delay
);
816 case SCAN_SET_CHANNEL
:
817 ieee80211_scan_state_set_channel(local
, &next_delay
);
819 case SCAN_SEND_PROBE
:
820 ieee80211_scan_state_send_probe(local
, &next_delay
);
823 ieee80211_scan_state_suspend(local
, &next_delay
);
826 ieee80211_scan_state_resume(local
, &next_delay
);
832 } while (next_delay
== 0);
834 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
, next_delay
);
838 hw_scan
= test_bit(SCAN_HW_SCANNING
, &local
->scanning
);
839 __ieee80211_scan_completed(&local
->hw
, aborted
, hw_scan
);
841 mutex_unlock(&local
->mtx
);
844 int ieee80211_request_scan(struct ieee80211_sub_if_data
*sdata
,
845 struct cfg80211_scan_request
*req
)
849 mutex_lock(&sdata
->local
->mtx
);
850 res
= __ieee80211_start_scan(sdata
, req
);
851 mutex_unlock(&sdata
->local
->mtx
);
856 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data
*sdata
,
857 const u8
*ssid
, u8 ssid_len
,
858 struct ieee80211_channel
*chan
,
859 enum nl80211_bss_scan_width scan_width
)
861 struct ieee80211_local
*local
= sdata
->local
;
863 enum ieee80211_band band
;
865 mutex_lock(&local
->mtx
);
871 /* fill internal scan request */
876 for (band
= 0; band
< IEEE80211_NUM_BANDS
; band
++) {
877 if (!local
->hw
.wiphy
->bands
[band
])
880 max_n
= local
->hw
.wiphy
->bands
[band
]->n_channels
;
881 for (i
= 0; i
< max_n
; i
++) {
882 struct ieee80211_channel
*tmp_ch
=
883 &local
->hw
.wiphy
->bands
[band
]->channels
[i
];
885 if (tmp_ch
->flags
& (IEEE80211_CHAN_NO_IBSS
|
886 IEEE80211_CHAN_DISABLED
))
889 local
->int_scan_req
->channels
[n_ch
] = tmp_ch
;
894 if (WARN_ON_ONCE(n_ch
== 0))
897 local
->int_scan_req
->n_channels
= n_ch
;
899 if (WARN_ON_ONCE(chan
->flags
& (IEEE80211_CHAN_NO_IBSS
|
900 IEEE80211_CHAN_DISABLED
)))
903 local
->int_scan_req
->channels
[0] = chan
;
904 local
->int_scan_req
->n_channels
= 1;
907 local
->int_scan_req
->ssids
= &local
->scan_ssid
;
908 local
->int_scan_req
->n_ssids
= 1;
909 local
->int_scan_req
->scan_width
= scan_width
;
910 memcpy(local
->int_scan_req
->ssids
[0].ssid
, ssid
, IEEE80211_MAX_SSID_LEN
);
911 local
->int_scan_req
->ssids
[0].ssid_len
= ssid_len
;
913 ret
= __ieee80211_start_scan(sdata
, sdata
->local
->int_scan_req
);
915 mutex_unlock(&local
->mtx
);
920 * Only call this function when a scan can't be queued -- under RTNL.
922 void ieee80211_scan_cancel(struct ieee80211_local
*local
)
925 * We are canceling software scan, or deferred scan that was not
926 * yet really started (see __ieee80211_start_scan ).
928 * Regarding hardware scan:
929 * - we can not call __ieee80211_scan_completed() as when
930 * SCAN_HW_SCANNING bit is set this function change
931 * local->hw_scan_req to operate on 5G band, what race with
932 * driver which can use local->hw_scan_req
934 * - we can not cancel scan_work since driver can schedule it
935 * by ieee80211_scan_completed(..., true) to finish scan
937 * Hence we only call the cancel_hw_scan() callback, but the low-level
938 * driver is still responsible for calling ieee80211_scan_completed()
939 * after the scan was completed/aborted.
942 mutex_lock(&local
->mtx
);
943 if (!local
->scan_req
)
947 * We have a scan running and the driver already reported completion,
948 * but the worker hasn't run yet or is stuck on the mutex - mark it as
951 if (test_bit(SCAN_HW_SCANNING
, &local
->scanning
) &&
952 test_bit(SCAN_COMPLETED
, &local
->scanning
)) {
953 set_bit(SCAN_HW_CANCELLED
, &local
->scanning
);
957 if (test_bit(SCAN_HW_SCANNING
, &local
->scanning
)) {
959 * Make sure that __ieee80211_scan_completed doesn't trigger a
960 * scan on another band.
962 set_bit(SCAN_HW_CANCELLED
, &local
->scanning
);
963 if (local
->ops
->cancel_hw_scan
)
964 drv_cancel_hw_scan(local
,
965 rcu_dereference_protected(local
->scan_sdata
,
966 lockdep_is_held(&local
->mtx
)));
971 * If the work is currently running, it must be blocked on
972 * the mutex, but we'll set scan_sdata = NULL and it'll
973 * simply exit once it acquires the mutex.
975 cancel_delayed_work(&local
->scan_work
);
977 __ieee80211_scan_completed(&local
->hw
, true, false);
979 mutex_unlock(&local
->mtx
);
982 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data
*sdata
,
983 struct cfg80211_sched_scan_request
*req
)
985 struct ieee80211_local
*local
= sdata
->local
;
986 struct ieee80211_sched_scan_ies sched_scan_ies
= {};
987 struct cfg80211_chan_def chandef
;
990 iebufsz
= 2 + IEEE80211_MAX_SSID_LEN
+
991 local
->scan_ies_len
+ req
->ie_len
;
993 mutex_lock(&local
->mtx
);
995 if (rcu_access_pointer(local
->sched_scan_sdata
)) {
1000 if (!local
->ops
->sched_scan_start
) {
1005 for (i
= 0; i
< IEEE80211_NUM_BANDS
; i
++) {
1006 if (!local
->hw
.wiphy
->bands
[i
])
1009 sched_scan_ies
.ie
[i
] = kzalloc(iebufsz
, GFP_KERNEL
);
1010 if (!sched_scan_ies
.ie
[i
]) {
1015 ieee80211_prepare_scan_chandef(&chandef
, req
->scan_width
);
1017 sched_scan_ies
.len
[i
] =
1018 ieee80211_build_preq_ies(local
, sched_scan_ies
.ie
[i
],
1019 iebufsz
, req
->ie
, req
->ie_len
,
1020 i
, (u32
) -1, &chandef
);
1023 ret
= drv_sched_scan_start(local
, sdata
, req
, &sched_scan_ies
);
1025 rcu_assign_pointer(local
->sched_scan_sdata
, sdata
);
1029 kfree(sched_scan_ies
.ie
[--i
]);
1031 mutex_unlock(&local
->mtx
);
1035 int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data
*sdata
)
1037 struct ieee80211_local
*local
= sdata
->local
;
1040 mutex_lock(&local
->mtx
);
1042 if (!local
->ops
->sched_scan_stop
) {
1047 if (rcu_access_pointer(local
->sched_scan_sdata
))
1048 drv_sched_scan_stop(local
, sdata
);
1051 mutex_unlock(&local
->mtx
);
1056 void ieee80211_sched_scan_results(struct ieee80211_hw
*hw
)
1058 struct ieee80211_local
*local
= hw_to_local(hw
);
1060 trace_api_sched_scan_results(local
);
1062 cfg80211_sched_scan_results(hw
->wiphy
);
1064 EXPORT_SYMBOL(ieee80211_sched_scan_results
);
1066 void ieee80211_sched_scan_stopped_work(struct work_struct
*work
)
1068 struct ieee80211_local
*local
=
1069 container_of(work
, struct ieee80211_local
,
1070 sched_scan_stopped_work
);
1072 mutex_lock(&local
->mtx
);
1074 if (!rcu_access_pointer(local
->sched_scan_sdata
)) {
1075 mutex_unlock(&local
->mtx
);
1079 rcu_assign_pointer(local
->sched_scan_sdata
, NULL
);
1081 mutex_unlock(&local
->mtx
);
1083 cfg80211_sched_scan_stopped(local
->hw
.wiphy
);
1086 void ieee80211_sched_scan_stopped(struct ieee80211_hw
*hw
)
1088 struct ieee80211_local
*local
= hw_to_local(hw
);
1090 trace_api_sched_scan_stopped(local
);
1092 ieee80211_queue_work(&local
->hw
, &local
->sched_scan_stopped_work
);
1094 EXPORT_SYMBOL(ieee80211_sched_scan_stopped
);