2 * Scanning implementation
4 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
5 * Copyright 2004, Instant802 Networks, Inc.
6 * Copyright 2005, Devicescape Software, Inc.
7 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
8 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
9 * Copyright 2013-2015 Intel Mobile Communications GmbH
10 * Copyright 2016-2017 Intel Deutschland GmbH
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
17 #include <linux/if_arp.h>
18 #include <linux/etherdevice.h>
19 #include <linux/rtnetlink.h>
20 #include <net/sch_generic.h>
21 #include <linux/slab.h>
22 #include <linux/export.h>
23 #include <linux/random.h>
24 #include <net/mac80211.h>
26 #include "ieee80211_i.h"
27 #include "driver-ops.h"
30 #define IEEE80211_PROBE_DELAY (HZ / 33)
31 #define IEEE80211_CHANNEL_TIME (HZ / 33)
32 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
34 void ieee80211_rx_bss_put(struct ieee80211_local
*local
,
35 struct ieee80211_bss
*bss
)
39 cfg80211_put_bss(local
->hw
.wiphy
,
40 container_of((void *)bss
, struct cfg80211_bss
, priv
));
43 static bool is_uapsd_supported(struct ieee802_11_elems
*elems
)
47 if (elems
->wmm_info
&& elems
->wmm_info_len
== 7
48 && elems
->wmm_info
[5] == 1)
49 qos_info
= elems
->wmm_info
[6];
50 else if (elems
->wmm_param
&& elems
->wmm_param_len
== 24
51 && elems
->wmm_param
[5] == 1)
52 qos_info
= elems
->wmm_param
[6];
54 /* no valid wmm information or parameter element found */
57 return qos_info
& IEEE80211_WMM_IE_AP_QOSINFO_UAPSD
;
60 struct ieee80211_bss
*
61 ieee80211_bss_info_update(struct ieee80211_local
*local
,
62 struct ieee80211_rx_status
*rx_status
,
63 struct ieee80211_mgmt
*mgmt
, size_t len
,
64 struct ieee802_11_elems
*elems
,
65 struct ieee80211_channel
*channel
)
67 bool beacon
= ieee80211_is_beacon(mgmt
->frame_control
);
68 struct cfg80211_bss
*cbss
;
69 struct ieee80211_bss
*bss
;
71 struct cfg80211_inform_bss bss_meta
= {
72 .boottime_ns
= rx_status
->boottime_ns
,
75 struct ieee80211_sub_if_data
*scan_sdata
;
77 if (rx_status
->flag
& RX_FLAG_NO_SIGNAL_VAL
)
78 bss_meta
.signal
= 0; /* invalid signal indication */
79 else if (ieee80211_hw_check(&local
->hw
, SIGNAL_DBM
))
80 bss_meta
.signal
= rx_status
->signal
* 100;
81 else if (ieee80211_hw_check(&local
->hw
, SIGNAL_UNSPEC
))
82 bss_meta
.signal
= (rx_status
->signal
* 100) / local
->hw
.max_signal
;
84 bss_meta
.scan_width
= NL80211_BSS_CHAN_WIDTH_20
;
85 if (rx_status
->bw
== RATE_INFO_BW_5
)
86 bss_meta
.scan_width
= NL80211_BSS_CHAN_WIDTH_5
;
87 else if (rx_status
->bw
== RATE_INFO_BW_10
)
88 bss_meta
.scan_width
= NL80211_BSS_CHAN_WIDTH_10
;
90 bss_meta
.chan
= channel
;
93 scan_sdata
= rcu_dereference(local
->scan_sdata
);
94 if (scan_sdata
&& scan_sdata
->vif
.type
== NL80211_IFTYPE_STATION
&&
95 scan_sdata
->vif
.bss_conf
.assoc
&&
96 ieee80211_have_rx_timestamp(rx_status
)) {
98 ieee80211_calculate_rx_timestamp(local
, rx_status
,
100 ether_addr_copy(bss_meta
.parent_bssid
,
101 scan_sdata
->vif
.bss_conf
.bssid
);
105 cbss
= cfg80211_inform_bss_frame_data(local
->hw
.wiphy
, &bss_meta
,
106 mgmt
, len
, GFP_ATOMIC
);
109 /* In case the signal is invalid update the status */
110 signal_valid
= abs(channel
->center_freq
- cbss
->channel
->center_freq
)
111 <= local
->hw
.wiphy
->max_adj_channel_rssi_comp
;
113 rx_status
->flag
|= RX_FLAG_NO_SIGNAL_VAL
;
115 bss
= (void *)cbss
->priv
;
118 bss
->device_ts_beacon
= rx_status
->device_timestamp
;
120 bss
->device_ts_presp
= rx_status
->device_timestamp
;
122 if (elems
->parse_error
) {
124 bss
->corrupt_data
|= IEEE80211_BSS_CORRUPT_BEACON
;
126 bss
->corrupt_data
|= IEEE80211_BSS_CORRUPT_PROBE_RESP
;
129 bss
->corrupt_data
&= ~IEEE80211_BSS_CORRUPT_BEACON
;
131 bss
->corrupt_data
&= ~IEEE80211_BSS_CORRUPT_PROBE_RESP
;
134 /* save the ERP value so that it is available at association time */
135 if (elems
->erp_info
&& (!elems
->parse_error
||
136 !(bss
->valid_data
& IEEE80211_BSS_VALID_ERP
))) {
137 bss
->erp_value
= elems
->erp_info
[0];
138 bss
->has_erp_value
= true;
139 if (!elems
->parse_error
)
140 bss
->valid_data
|= IEEE80211_BSS_VALID_ERP
;
143 /* replace old supported rates if we get new values */
144 if (!elems
->parse_error
||
145 !(bss
->valid_data
& IEEE80211_BSS_VALID_RATES
)) {
147 if (elems
->supp_rates
) {
148 clen
= IEEE80211_MAX_SUPP_RATES
;
149 if (clen
> elems
->supp_rates_len
)
150 clen
= elems
->supp_rates_len
;
151 memcpy(bss
->supp_rates
, elems
->supp_rates
, clen
);
154 if (elems
->ext_supp_rates
) {
155 clen
= IEEE80211_MAX_SUPP_RATES
- srlen
;
156 if (clen
> elems
->ext_supp_rates_len
)
157 clen
= elems
->ext_supp_rates_len
;
158 memcpy(bss
->supp_rates
+ srlen
, elems
->ext_supp_rates
,
163 bss
->supp_rates_len
= srlen
;
164 if (!elems
->parse_error
)
165 bss
->valid_data
|= IEEE80211_BSS_VALID_RATES
;
169 if (!elems
->parse_error
||
170 !(bss
->valid_data
& IEEE80211_BSS_VALID_WMM
)) {
171 bss
->wmm_used
= elems
->wmm_param
|| elems
->wmm_info
;
172 bss
->uapsd_supported
= is_uapsd_supported(elems
);
173 if (!elems
->parse_error
)
174 bss
->valid_data
|= IEEE80211_BSS_VALID_WMM
;
178 struct ieee80211_supported_band
*sband
=
179 local
->hw
.wiphy
->bands
[rx_status
->band
];
180 if (!(rx_status
->encoding
== RX_ENC_HT
) &&
181 !(rx_status
->encoding
== RX_ENC_VHT
))
183 &sband
->bitrates
[rx_status
->rate_idx
];
189 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data
*sdata
,
190 u32 scan_flags
, const u8
*da
)
194 /* accept broadcast for OCE */
195 if (scan_flags
& NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP
&&
196 is_broadcast_ether_addr(da
))
198 if (scan_flags
& NL80211_SCAN_FLAG_RANDOM_ADDR
)
200 return ether_addr_equal(da
, sdata
->vif
.addr
);
203 void ieee80211_scan_rx(struct ieee80211_local
*local
, struct sk_buff
*skb
)
205 struct ieee80211_rx_status
*rx_status
= IEEE80211_SKB_RXCB(skb
);
206 struct ieee80211_sub_if_data
*sdata1
, *sdata2
;
207 struct ieee80211_mgmt
*mgmt
= (void *)skb
->data
;
208 struct ieee80211_bss
*bss
;
210 struct ieee80211_channel
*channel
;
212 struct ieee802_11_elems elems
;
215 (!ieee80211_is_probe_resp(mgmt
->frame_control
) &&
216 !ieee80211_is_beacon(mgmt
->frame_control
)))
219 sdata1
= rcu_dereference(local
->scan_sdata
);
220 sdata2
= rcu_dereference(local
->sched_scan_sdata
);
222 if (likely(!sdata1
&& !sdata2
))
225 if (ieee80211_is_probe_resp(mgmt
->frame_control
)) {
226 struct cfg80211_scan_request
*scan_req
;
227 struct cfg80211_sched_scan_request
*sched_scan_req
;
228 u32 scan_req_flags
= 0, sched_scan_req_flags
= 0;
230 scan_req
= rcu_dereference(local
->scan_req
);
231 sched_scan_req
= rcu_dereference(local
->sched_scan_req
);
234 scan_req_flags
= scan_req
->flags
;
237 sched_scan_req_flags
= sched_scan_req
->flags
;
239 /* ignore ProbeResp to foreign address or non-bcast (OCE)
240 * unless scanning with randomised address
242 if (!ieee80211_scan_accept_presp(sdata1
, scan_req_flags
,
244 !ieee80211_scan_accept_presp(sdata2
, sched_scan_req_flags
,
248 elements
= mgmt
->u
.probe_resp
.variable
;
249 baselen
= offsetof(struct ieee80211_mgmt
, u
.probe_resp
.variable
);
251 baselen
= offsetof(struct ieee80211_mgmt
, u
.beacon
.variable
);
252 elements
= mgmt
->u
.beacon
.variable
;
255 if (baselen
> skb
->len
)
258 ieee802_11_parse_elems(elements
, skb
->len
- baselen
, false, &elems
);
260 channel
= ieee80211_get_channel(local
->hw
.wiphy
, rx_status
->freq
);
262 if (!channel
|| channel
->flags
& IEEE80211_CHAN_DISABLED
)
265 bss
= ieee80211_bss_info_update(local
, rx_status
,
266 mgmt
, skb
->len
, &elems
,
269 ieee80211_rx_bss_put(local
, bss
);
273 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def
*chandef
,
274 enum nl80211_bss_scan_width scan_width
)
276 memset(chandef
, 0, sizeof(*chandef
));
277 switch (scan_width
) {
278 case NL80211_BSS_CHAN_WIDTH_5
:
279 chandef
->width
= NL80211_CHAN_WIDTH_5
;
281 case NL80211_BSS_CHAN_WIDTH_10
:
282 chandef
->width
= NL80211_CHAN_WIDTH_10
;
285 chandef
->width
= NL80211_CHAN_WIDTH_20_NOHT
;
290 /* return false if no more work */
291 static bool ieee80211_prep_hw_scan(struct ieee80211_local
*local
)
293 struct cfg80211_scan_request
*req
;
294 struct cfg80211_chan_def chandef
;
296 int i
, ielen
, n_chans
;
299 req
= rcu_dereference_protected(local
->scan_req
,
300 lockdep_is_held(&local
->mtx
));
302 if (test_bit(SCAN_HW_CANCELLED
, &local
->scanning
))
305 if (ieee80211_hw_check(&local
->hw
, SINGLE_SCAN_ON_ALL_BANDS
)) {
306 for (i
= 0; i
< req
->n_channels
; i
++) {
307 local
->hw_scan_req
->req
.channels
[i
] = req
->channels
[i
];
308 bands_used
|= BIT(req
->channels
[i
]->band
);
311 n_chans
= req
->n_channels
;
314 if (local
->hw_scan_band
== NUM_NL80211_BANDS
)
319 for (i
= 0; i
< req
->n_channels
; i
++) {
320 if (req
->channels
[i
]->band
!=
323 local
->hw_scan_req
->req
.channels
[n_chans
] =
326 bands_used
|= BIT(req
->channels
[i
]->band
);
329 local
->hw_scan_band
++;
333 local
->hw_scan_req
->req
.n_channels
= n_chans
;
334 ieee80211_prepare_scan_chandef(&chandef
, req
->scan_width
);
336 if (req
->flags
& NL80211_SCAN_FLAG_MIN_PREQ_CONTENT
)
337 flags
|= IEEE80211_PROBE_FLAG_MIN_CONTENT
;
339 ielen
= ieee80211_build_preq_ies(local
,
340 (u8
*)local
->hw_scan_req
->req
.ie
,
341 local
->hw_scan_ies_bufsize
,
342 &local
->hw_scan_req
->ies
,
343 req
->ie
, req
->ie_len
,
344 bands_used
, req
->rates
, &chandef
,
346 local
->hw_scan_req
->req
.ie_len
= ielen
;
347 local
->hw_scan_req
->req
.no_cck
= req
->no_cck
;
348 ether_addr_copy(local
->hw_scan_req
->req
.mac_addr
, req
->mac_addr
);
349 ether_addr_copy(local
->hw_scan_req
->req
.mac_addr_mask
,
351 ether_addr_copy(local
->hw_scan_req
->req
.bssid
, req
->bssid
);
356 static void __ieee80211_scan_completed(struct ieee80211_hw
*hw
, bool aborted
)
358 struct ieee80211_local
*local
= hw_to_local(hw
);
359 bool hw_scan
= local
->ops
->hw_scan
;
360 bool was_scanning
= local
->scanning
;
361 struct cfg80211_scan_request
*scan_req
;
362 struct ieee80211_sub_if_data
*scan_sdata
;
363 struct ieee80211_sub_if_data
*sdata
;
365 lockdep_assert_held(&local
->mtx
);
368 * It's ok to abort a not-yet-running scan (that
369 * we have one at all will be verified by checking
370 * local->scan_req next), but not to complete it
373 if (WARN_ON(!local
->scanning
&& !aborted
))
376 if (WARN_ON(!local
->scan_req
))
379 if (hw_scan
&& !aborted
&&
380 !ieee80211_hw_check(&local
->hw
, SINGLE_SCAN_ON_ALL_BANDS
) &&
381 ieee80211_prep_hw_scan(local
)) {
384 rc
= drv_hw_scan(local
,
385 rcu_dereference_protected(local
->scan_sdata
,
386 lockdep_is_held(&local
->mtx
)),
392 /* HW scan failed and is going to be reported as aborted,
393 * so clear old scan info.
395 memset(&local
->scan_info
, 0, sizeof(local
->scan_info
));
399 kfree(local
->hw_scan_req
);
400 local
->hw_scan_req
= NULL
;
402 scan_req
= rcu_dereference_protected(local
->scan_req
,
403 lockdep_is_held(&local
->mtx
));
405 if (scan_req
!= local
->int_scan_req
) {
406 local
->scan_info
.aborted
= aborted
;
407 cfg80211_scan_done(scan_req
, &local
->scan_info
);
409 RCU_INIT_POINTER(local
->scan_req
, NULL
);
411 scan_sdata
= rcu_dereference_protected(local
->scan_sdata
,
412 lockdep_is_held(&local
->mtx
));
413 RCU_INIT_POINTER(local
->scan_sdata
, NULL
);
416 local
->scan_chandef
.chan
= NULL
;
418 /* Set power back to normal operating levels. */
419 ieee80211_hw_config(local
, 0);
422 ieee80211_configure_filter(local
);
423 drv_sw_scan_complete(local
, scan_sdata
);
424 ieee80211_offchannel_return(local
);
427 ieee80211_recalc_idle(local
);
429 ieee80211_mlme_notify_scan_completed(local
);
430 ieee80211_ibss_notify_scan_completed(local
);
432 /* Requeue all the work that might have been ignored while
433 * the scan was in progress; if there was none this will
434 * just be a no-op for the particular interface.
436 list_for_each_entry_rcu(sdata
, &local
->interfaces
, list
) {
437 if (ieee80211_sdata_running(sdata
))
438 ieee80211_queue_work(&sdata
->local
->hw
, &sdata
->work
);
442 ieee80211_start_next_roc(local
);
445 void ieee80211_scan_completed(struct ieee80211_hw
*hw
,
446 struct cfg80211_scan_info
*info
)
448 struct ieee80211_local
*local
= hw_to_local(hw
);
450 trace_api_scan_completed(local
, info
->aborted
);
452 set_bit(SCAN_COMPLETED
, &local
->scanning
);
454 set_bit(SCAN_ABORTED
, &local
->scanning
);
456 memcpy(&local
->scan_info
, info
, sizeof(*info
));
458 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
, 0);
460 EXPORT_SYMBOL(ieee80211_scan_completed
);
462 static int ieee80211_start_sw_scan(struct ieee80211_local
*local
,
463 struct ieee80211_sub_if_data
*sdata
)
465 /* Software scan is not supported in multi-channel cases */
466 if (local
->use_chanctx
)
470 * Hardware/driver doesn't support hw_scan, so use software
471 * scanning instead. First send a nullfunc frame with power save
472 * bit on so that AP will buffer the frames for us while we are not
473 * listening, then send probe requests to each channel and wait for
474 * the responses. After all channels are scanned, tune back to the
475 * original channel and send a nullfunc frame with power save bit
476 * off to trigger the AP to send us all the buffered frames.
478 * Note that while local->sw_scanning is true everything else but
479 * nullfunc frames and probe requests will be dropped in
480 * ieee80211_tx_h_check_assoc().
482 drv_sw_scan_start(local
, sdata
, local
->scan_addr
);
484 local
->leave_oper_channel_time
= jiffies
;
485 local
->next_scan_state
= SCAN_DECISION
;
486 local
->scan_channel_idx
= 0;
488 ieee80211_offchannel_stop_vifs(local
);
490 /* ensure nullfunc is transmitted before leaving operating channel */
491 ieee80211_flush_queues(local
, NULL
, false);
493 ieee80211_configure_filter(local
);
495 /* We need to set power level at maximum rate for scanning. */
496 ieee80211_hw_config(local
, 0);
498 ieee80211_queue_delayed_work(&local
->hw
,
499 &local
->scan_work
, 0);
504 static bool ieee80211_can_scan(struct ieee80211_local
*local
,
505 struct ieee80211_sub_if_data
*sdata
)
507 if (ieee80211_is_radar_required(local
))
510 if (!list_empty(&local
->roc_list
))
513 if (sdata
->vif
.type
== NL80211_IFTYPE_STATION
&&
514 sdata
->u
.mgd
.flags
& IEEE80211_STA_CONNECTION_POLL
)
520 void ieee80211_run_deferred_scan(struct ieee80211_local
*local
)
522 lockdep_assert_held(&local
->mtx
);
524 if (!local
->scan_req
|| local
->scanning
)
527 if (!ieee80211_can_scan(local
,
528 rcu_dereference_protected(
530 lockdep_is_held(&local
->mtx
))))
533 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
,
534 round_jiffies_relative(0));
537 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data
*sdata
,
538 const u8
*src
, const u8
*dst
,
539 const u8
*ssid
, size_t ssid_len
,
540 const u8
*ie
, size_t ie_len
,
541 u32 ratemask
, u32 flags
, u32 tx_flags
,
542 struct ieee80211_channel
*channel
)
545 u32 txdata_flags
= 0;
547 skb
= ieee80211_build_probe_req(sdata
, src
, dst
, ratemask
, channel
,
552 if (flags
& IEEE80211_PROBE_FLAG_RANDOM_SN
) {
553 struct ieee80211_hdr
*hdr
= (void *)skb
->data
;
554 u16 sn
= get_random_u32();
556 txdata_flags
|= IEEE80211_TX_NO_SEQNO
;
558 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn
));
560 IEEE80211_SKB_CB(skb
)->flags
|= tx_flags
;
561 ieee80211_tx_skb_tid_band(sdata
, skb
, 7, channel
->band
,
566 static void ieee80211_scan_state_send_probe(struct ieee80211_local
*local
,
567 unsigned long *next_delay
)
570 struct ieee80211_sub_if_data
*sdata
;
571 struct cfg80211_scan_request
*scan_req
;
572 enum nl80211_band band
= local
->hw
.conf
.chandef
.chan
->band
;
573 u32 flags
= 0, tx_flags
;
575 scan_req
= rcu_dereference_protected(local
->scan_req
,
576 lockdep_is_held(&local
->mtx
));
578 tx_flags
= IEEE80211_TX_INTFL_OFFCHAN_TX_OK
;
579 if (scan_req
->no_cck
)
580 tx_flags
|= IEEE80211_TX_CTL_NO_CCK_RATE
;
581 if (scan_req
->flags
& NL80211_SCAN_FLAG_MIN_PREQ_CONTENT
)
582 flags
|= IEEE80211_PROBE_FLAG_MIN_CONTENT
;
583 if (scan_req
->flags
& NL80211_SCAN_FLAG_RANDOM_SN
)
584 flags
|= IEEE80211_PROBE_FLAG_RANDOM_SN
;
586 sdata
= rcu_dereference_protected(local
->scan_sdata
,
587 lockdep_is_held(&local
->mtx
));
589 for (i
= 0; i
< scan_req
->n_ssids
; i
++)
590 ieee80211_send_scan_probe_req(
591 sdata
, local
->scan_addr
, scan_req
->bssid
,
592 scan_req
->ssids
[i
].ssid
, scan_req
->ssids
[i
].ssid_len
,
593 scan_req
->ie
, scan_req
->ie_len
,
594 scan_req
->rates
[band
], flags
,
595 tx_flags
, local
->hw
.conf
.chandef
.chan
);
598 * After sending probe requests, wait for probe responses
601 *next_delay
= IEEE80211_CHANNEL_TIME
;
602 local
->next_scan_state
= SCAN_DECISION
;
605 static int __ieee80211_start_scan(struct ieee80211_sub_if_data
*sdata
,
606 struct cfg80211_scan_request
*req
)
608 struct ieee80211_local
*local
= sdata
->local
;
611 lockdep_assert_held(&local
->mtx
);
613 if (local
->scan_req
|| ieee80211_is_radar_required(local
))
616 if (!ieee80211_can_scan(local
, sdata
)) {
617 /* wait for the work to finish/time out */
618 rcu_assign_pointer(local
->scan_req
, req
);
619 rcu_assign_pointer(local
->scan_sdata
, sdata
);
623 if (local
->ops
->hw_scan
) {
626 local
->hw_scan_ies_bufsize
= local
->scan_ies_len
+ req
->ie_len
;
628 if (ieee80211_hw_check(&local
->hw
, SINGLE_SCAN_ON_ALL_BANDS
)) {
630 u8 bands_counted
= 0;
632 for (i
= 0; i
< req
->n_channels
; i
++) {
633 if (bands_counted
& BIT(req
->channels
[i
]->band
))
635 bands_counted
|= BIT(req
->channels
[i
]->band
);
639 local
->hw_scan_ies_bufsize
*= n_bands
;
642 local
->hw_scan_req
= kmalloc(
643 sizeof(*local
->hw_scan_req
) +
644 req
->n_channels
* sizeof(req
->channels
[0]) +
645 local
->hw_scan_ies_bufsize
, GFP_KERNEL
);
646 if (!local
->hw_scan_req
)
649 local
->hw_scan_req
->req
.ssids
= req
->ssids
;
650 local
->hw_scan_req
->req
.n_ssids
= req
->n_ssids
;
651 ies
= (u8
*)local
->hw_scan_req
+
652 sizeof(*local
->hw_scan_req
) +
653 req
->n_channels
* sizeof(req
->channels
[0]);
654 local
->hw_scan_req
->req
.ie
= ies
;
655 local
->hw_scan_req
->req
.flags
= req
->flags
;
656 eth_broadcast_addr(local
->hw_scan_req
->req
.bssid
);
657 local
->hw_scan_req
->req
.duration
= req
->duration
;
658 local
->hw_scan_req
->req
.duration_mandatory
=
659 req
->duration_mandatory
;
661 local
->hw_scan_band
= 0;
664 * After allocating local->hw_scan_req, we must
665 * go through until ieee80211_prep_hw_scan(), so
666 * anything that might be changed here and leave
667 * this function early must not go after this
672 rcu_assign_pointer(local
->scan_req
, req
);
673 rcu_assign_pointer(local
->scan_sdata
, sdata
);
675 if (req
->flags
& NL80211_SCAN_FLAG_RANDOM_ADDR
)
676 get_random_mask_addr(local
->scan_addr
,
680 memcpy(local
->scan_addr
, sdata
->vif
.addr
, ETH_ALEN
);
682 if (local
->ops
->hw_scan
) {
683 __set_bit(SCAN_HW_SCANNING
, &local
->scanning
);
684 } else if ((req
->n_channels
== 1) &&
685 (req
->channels
[0] == local
->_oper_chandef
.chan
)) {
687 * If we are scanning only on the operating channel
688 * then we do not need to stop normal activities
690 unsigned long next_delay
;
692 __set_bit(SCAN_ONCHANNEL_SCANNING
, &local
->scanning
);
694 ieee80211_recalc_idle(local
);
696 /* Notify driver scan is starting, keep order of operations
697 * same as normal software scan, in case that matters. */
698 drv_sw_scan_start(local
, sdata
, local
->scan_addr
);
700 ieee80211_configure_filter(local
); /* accept probe-responses */
702 /* We need to ensure power level is at max for scanning. */
703 ieee80211_hw_config(local
, 0);
705 if ((req
->channels
[0]->flags
& (IEEE80211_CHAN_NO_IR
|
706 IEEE80211_CHAN_RADAR
)) ||
708 next_delay
= IEEE80211_PASSIVE_CHANNEL_TIME
;
710 ieee80211_scan_state_send_probe(local
, &next_delay
);
711 next_delay
= IEEE80211_CHANNEL_TIME
;
714 /* Now, just wait a bit and we are all done! */
715 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
,
719 /* Do normal software scan */
720 __set_bit(SCAN_SW_SCANNING
, &local
->scanning
);
723 ieee80211_recalc_idle(local
);
725 if (local
->ops
->hw_scan
) {
726 WARN_ON(!ieee80211_prep_hw_scan(local
));
727 rc
= drv_hw_scan(local
, sdata
, local
->hw_scan_req
);
729 rc
= ieee80211_start_sw_scan(local
, sdata
);
733 kfree(local
->hw_scan_req
);
734 local
->hw_scan_req
= NULL
;
737 ieee80211_recalc_idle(local
);
739 local
->scan_req
= NULL
;
740 RCU_INIT_POINTER(local
->scan_sdata
, NULL
);
747 ieee80211_scan_get_channel_time(struct ieee80211_channel
*chan
)
750 * TODO: channel switching also consumes quite some time,
751 * add that delay as well to get a better estimation
753 if (chan
->flags
& (IEEE80211_CHAN_NO_IR
| IEEE80211_CHAN_RADAR
))
754 return IEEE80211_PASSIVE_CHANNEL_TIME
;
755 return IEEE80211_PROBE_DELAY
+ IEEE80211_CHANNEL_TIME
;
758 static void ieee80211_scan_state_decision(struct ieee80211_local
*local
,
759 unsigned long *next_delay
)
761 bool associated
= false;
762 bool tx_empty
= true;
764 struct ieee80211_sub_if_data
*sdata
;
765 struct ieee80211_channel
*next_chan
;
766 enum mac80211_scan_state next_scan_state
;
767 struct cfg80211_scan_request
*scan_req
;
770 * check if at least one STA interface is associated,
771 * check if at least one STA interface has pending tx frames
772 * and grab the lowest used beacon interval
774 mutex_lock(&local
->iflist_mtx
);
775 list_for_each_entry(sdata
, &local
->interfaces
, list
) {
776 if (!ieee80211_sdata_running(sdata
))
779 if (sdata
->vif
.type
== NL80211_IFTYPE_STATION
) {
780 if (sdata
->u
.mgd
.associated
) {
783 if (!qdisc_all_tx_empty(sdata
->dev
)) {
790 mutex_unlock(&local
->iflist_mtx
);
792 scan_req
= rcu_dereference_protected(local
->scan_req
,
793 lockdep_is_held(&local
->mtx
));
795 next_chan
= scan_req
->channels
[local
->scan_channel_idx
];
798 * we're currently scanning a different channel, let's
799 * see if we can scan another channel without interfering
800 * with the current traffic situation.
802 * Keep good latency, do not stay off-channel more than 125 ms.
805 bad_latency
= time_after(jiffies
+
806 ieee80211_scan_get_channel_time(next_chan
),
807 local
->leave_oper_channel_time
+ HZ
/ 8);
809 if (associated
&& !tx_empty
) {
810 if (scan_req
->flags
& NL80211_SCAN_FLAG_LOW_PRIORITY
)
811 next_scan_state
= SCAN_ABORT
;
813 next_scan_state
= SCAN_SUSPEND
;
814 } else if (associated
&& bad_latency
) {
815 next_scan_state
= SCAN_SUSPEND
;
817 next_scan_state
= SCAN_SET_CHANNEL
;
820 local
->next_scan_state
= next_scan_state
;
825 static void ieee80211_scan_state_set_channel(struct ieee80211_local
*local
,
826 unsigned long *next_delay
)
829 struct ieee80211_channel
*chan
;
830 enum nl80211_bss_scan_width oper_scan_width
;
831 struct cfg80211_scan_request
*scan_req
;
833 scan_req
= rcu_dereference_protected(local
->scan_req
,
834 lockdep_is_held(&local
->mtx
));
837 chan
= scan_req
->channels
[local
->scan_channel_idx
];
839 local
->scan_chandef
.chan
= chan
;
840 local
->scan_chandef
.center_freq1
= chan
->center_freq
;
841 local
->scan_chandef
.center_freq2
= 0;
842 switch (scan_req
->scan_width
) {
843 case NL80211_BSS_CHAN_WIDTH_5
:
844 local
->scan_chandef
.width
= NL80211_CHAN_WIDTH_5
;
846 case NL80211_BSS_CHAN_WIDTH_10
:
847 local
->scan_chandef
.width
= NL80211_CHAN_WIDTH_10
;
849 case NL80211_BSS_CHAN_WIDTH_20
:
850 /* If scanning on oper channel, use whatever channel-type
851 * is currently in use.
853 oper_scan_width
= cfg80211_chandef_to_scan_width(
854 &local
->_oper_chandef
);
855 if (chan
== local
->_oper_chandef
.chan
&&
856 oper_scan_width
== scan_req
->scan_width
)
857 local
->scan_chandef
= local
->_oper_chandef
;
859 local
->scan_chandef
.width
= NL80211_CHAN_WIDTH_20_NOHT
;
863 if (ieee80211_hw_config(local
, IEEE80211_CONF_CHANGE_CHANNEL
))
866 /* advance state machine to next channel/band */
867 local
->scan_channel_idx
++;
870 /* if we skip this channel return to the decision state */
871 local
->next_scan_state
= SCAN_DECISION
;
876 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
877 * (which unfortunately doesn't say _why_ step a) is done,
878 * but it waits for the probe delay or until a frame is
879 * received - and the received frame would update the NAV).
880 * For now, we do not support waiting until a frame is
883 * In any case, it is not necessary for a passive scan.
885 if ((chan
->flags
& (IEEE80211_CHAN_NO_IR
| IEEE80211_CHAN_RADAR
)) ||
886 !scan_req
->n_ssids
) {
887 *next_delay
= IEEE80211_PASSIVE_CHANNEL_TIME
;
888 local
->next_scan_state
= SCAN_DECISION
;
892 /* active scan, send probes */
893 *next_delay
= IEEE80211_PROBE_DELAY
;
894 local
->next_scan_state
= SCAN_SEND_PROBE
;
897 static void ieee80211_scan_state_suspend(struct ieee80211_local
*local
,
898 unsigned long *next_delay
)
900 /* switch back to the operating channel */
901 local
->scan_chandef
.chan
= NULL
;
902 ieee80211_hw_config(local
, IEEE80211_CONF_CHANGE_CHANNEL
);
905 ieee80211_offchannel_return(local
);
907 *next_delay
= HZ
/ 5;
908 /* afterwards, resume scan & go to next channel */
909 local
->next_scan_state
= SCAN_RESUME
;
912 static void ieee80211_scan_state_resume(struct ieee80211_local
*local
,
913 unsigned long *next_delay
)
915 ieee80211_offchannel_stop_vifs(local
);
917 if (local
->ops
->flush
) {
918 ieee80211_flush_queues(local
, NULL
, false);
921 *next_delay
= HZ
/ 10;
923 /* remember when we left the operating channel */
924 local
->leave_oper_channel_time
= jiffies
;
926 /* advance to the next channel to be scanned */
927 local
->next_scan_state
= SCAN_SET_CHANNEL
;
930 void ieee80211_scan_work(struct work_struct
*work
)
932 struct ieee80211_local
*local
=
933 container_of(work
, struct ieee80211_local
, scan_work
.work
);
934 struct ieee80211_sub_if_data
*sdata
;
935 struct cfg80211_scan_request
*scan_req
;
936 unsigned long next_delay
= 0;
939 mutex_lock(&local
->mtx
);
941 if (!ieee80211_can_run_worker(local
)) {
946 sdata
= rcu_dereference_protected(local
->scan_sdata
,
947 lockdep_is_held(&local
->mtx
));
948 scan_req
= rcu_dereference_protected(local
->scan_req
,
949 lockdep_is_held(&local
->mtx
));
951 /* When scanning on-channel, the first-callback means completed. */
952 if (test_bit(SCAN_ONCHANNEL_SCANNING
, &local
->scanning
)) {
953 aborted
= test_and_clear_bit(SCAN_ABORTED
, &local
->scanning
);
957 if (test_and_clear_bit(SCAN_COMPLETED
, &local
->scanning
)) {
958 aborted
= test_and_clear_bit(SCAN_ABORTED
, &local
->scanning
);
962 if (!sdata
|| !scan_req
)
965 if (!local
->scanning
) {
968 RCU_INIT_POINTER(local
->scan_req
, NULL
);
969 RCU_INIT_POINTER(local
->scan_sdata
, NULL
);
971 rc
= __ieee80211_start_scan(sdata
, scan_req
);
973 /* need to complete scan in cfg80211 */
974 rcu_assign_pointer(local
->scan_req
, scan_req
);
982 * as long as no delay is required advance immediately
983 * without scheduling a new work
986 if (!ieee80211_sdata_running(sdata
)) {
991 switch (local
->next_scan_state
) {
993 /* if no more bands/channels left, complete scan */
994 if (local
->scan_channel_idx
>= scan_req
->n_channels
) {
998 ieee80211_scan_state_decision(local
, &next_delay
);
1000 case SCAN_SET_CHANNEL
:
1001 ieee80211_scan_state_set_channel(local
, &next_delay
);
1003 case SCAN_SEND_PROBE
:
1004 ieee80211_scan_state_send_probe(local
, &next_delay
);
1007 ieee80211_scan_state_suspend(local
, &next_delay
);
1010 ieee80211_scan_state_resume(local
, &next_delay
);
1016 } while (next_delay
== 0);
1018 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
, next_delay
);
1022 __ieee80211_scan_completed(&local
->hw
, aborted
);
1024 mutex_unlock(&local
->mtx
);
1027 int ieee80211_request_scan(struct ieee80211_sub_if_data
*sdata
,
1028 struct cfg80211_scan_request
*req
)
1032 mutex_lock(&sdata
->local
->mtx
);
1033 res
= __ieee80211_start_scan(sdata
, req
);
1034 mutex_unlock(&sdata
->local
->mtx
);
1039 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data
*sdata
,
1040 const u8
*ssid
, u8 ssid_len
,
1041 struct ieee80211_channel
**channels
,
1042 unsigned int n_channels
,
1043 enum nl80211_bss_scan_width scan_width
)
1045 struct ieee80211_local
*local
= sdata
->local
;
1046 int ret
= -EBUSY
, i
, n_ch
= 0;
1047 enum nl80211_band band
;
1049 mutex_lock(&local
->mtx
);
1052 if (local
->scan_req
)
1055 /* fill internal scan request */
1059 for (band
= 0; band
< NUM_NL80211_BANDS
; band
++) {
1060 if (!local
->hw
.wiphy
->bands
[band
])
1063 max_n
= local
->hw
.wiphy
->bands
[band
]->n_channels
;
1064 for (i
= 0; i
< max_n
; i
++) {
1065 struct ieee80211_channel
*tmp_ch
=
1066 &local
->hw
.wiphy
->bands
[band
]->channels
[i
];
1068 if (tmp_ch
->flags
& (IEEE80211_CHAN_NO_IR
|
1069 IEEE80211_CHAN_DISABLED
))
1072 local
->int_scan_req
->channels
[n_ch
] = tmp_ch
;
1077 if (WARN_ON_ONCE(n_ch
== 0))
1080 local
->int_scan_req
->n_channels
= n_ch
;
1082 for (i
= 0; i
< n_channels
; i
++) {
1083 if (channels
[i
]->flags
& (IEEE80211_CHAN_NO_IR
|
1084 IEEE80211_CHAN_DISABLED
))
1087 local
->int_scan_req
->channels
[n_ch
] = channels
[i
];
1091 if (WARN_ON_ONCE(n_ch
== 0))
1094 local
->int_scan_req
->n_channels
= n_ch
;
1097 local
->int_scan_req
->ssids
= &local
->scan_ssid
;
1098 local
->int_scan_req
->n_ssids
= 1;
1099 local
->int_scan_req
->scan_width
= scan_width
;
1100 memcpy(local
->int_scan_req
->ssids
[0].ssid
, ssid
, IEEE80211_MAX_SSID_LEN
);
1101 local
->int_scan_req
->ssids
[0].ssid_len
= ssid_len
;
1103 ret
= __ieee80211_start_scan(sdata
, sdata
->local
->int_scan_req
);
1105 mutex_unlock(&local
->mtx
);
1110 * Only call this function when a scan can't be queued -- under RTNL.
1112 void ieee80211_scan_cancel(struct ieee80211_local
*local
)
1115 * We are canceling software scan, or deferred scan that was not
1116 * yet really started (see __ieee80211_start_scan ).
1118 * Regarding hardware scan:
1119 * - we can not call __ieee80211_scan_completed() as when
1120 * SCAN_HW_SCANNING bit is set this function change
1121 * local->hw_scan_req to operate on 5G band, what race with
1122 * driver which can use local->hw_scan_req
1124 * - we can not cancel scan_work since driver can schedule it
1125 * by ieee80211_scan_completed(..., true) to finish scan
1127 * Hence we only call the cancel_hw_scan() callback, but the low-level
1128 * driver is still responsible for calling ieee80211_scan_completed()
1129 * after the scan was completed/aborted.
1132 mutex_lock(&local
->mtx
);
1133 if (!local
->scan_req
)
1137 * We have a scan running and the driver already reported completion,
1138 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1141 if (test_bit(SCAN_HW_SCANNING
, &local
->scanning
) &&
1142 test_bit(SCAN_COMPLETED
, &local
->scanning
)) {
1143 set_bit(SCAN_HW_CANCELLED
, &local
->scanning
);
1147 if (test_bit(SCAN_HW_SCANNING
, &local
->scanning
)) {
1149 * Make sure that __ieee80211_scan_completed doesn't trigger a
1150 * scan on another band.
1152 set_bit(SCAN_HW_CANCELLED
, &local
->scanning
);
1153 if (local
->ops
->cancel_hw_scan
)
1154 drv_cancel_hw_scan(local
,
1155 rcu_dereference_protected(local
->scan_sdata
,
1156 lockdep_is_held(&local
->mtx
)));
1161 * If the work is currently running, it must be blocked on
1162 * the mutex, but we'll set scan_sdata = NULL and it'll
1163 * simply exit once it acquires the mutex.
1165 cancel_delayed_work(&local
->scan_work
);
1167 memset(&local
->scan_info
, 0, sizeof(local
->scan_info
));
1168 __ieee80211_scan_completed(&local
->hw
, true);
1170 mutex_unlock(&local
->mtx
);
1173 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data
*sdata
,
1174 struct cfg80211_sched_scan_request
*req
)
1176 struct ieee80211_local
*local
= sdata
->local
;
1177 struct ieee80211_scan_ies sched_scan_ies
= {};
1178 struct cfg80211_chan_def chandef
;
1179 int ret
, i
, iebufsz
, num_bands
= 0;
1180 u32 rate_masks
[NUM_NL80211_BANDS
] = {};
1185 iebufsz
= local
->scan_ies_len
+ req
->ie_len
;
1187 lockdep_assert_held(&local
->mtx
);
1189 if (!local
->ops
->sched_scan_start
)
1192 for (i
= 0; i
< NUM_NL80211_BANDS
; i
++) {
1193 if (local
->hw
.wiphy
->bands
[i
]) {
1194 bands_used
|= BIT(i
);
1195 rate_masks
[i
] = (u32
) -1;
1200 if (req
->flags
& NL80211_SCAN_FLAG_MIN_PREQ_CONTENT
)
1201 flags
|= IEEE80211_PROBE_FLAG_MIN_CONTENT
;
1203 ie
= kcalloc(iebufsz
, num_bands
, GFP_KERNEL
);
1209 ieee80211_prepare_scan_chandef(&chandef
, req
->scan_width
);
1211 ieee80211_build_preq_ies(local
, ie
, num_bands
* iebufsz
,
1212 &sched_scan_ies
, req
->ie
,
1213 req
->ie_len
, bands_used
, rate_masks
, &chandef
,
1216 ret
= drv_sched_scan_start(local
, sdata
, req
, &sched_scan_ies
);
1218 rcu_assign_pointer(local
->sched_scan_sdata
, sdata
);
1219 rcu_assign_pointer(local
->sched_scan_req
, req
);
1226 /* Clean in case of failure after HW restart or upon resume. */
1227 RCU_INIT_POINTER(local
->sched_scan_sdata
, NULL
);
1228 RCU_INIT_POINTER(local
->sched_scan_req
, NULL
);
1234 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data
*sdata
,
1235 struct cfg80211_sched_scan_request
*req
)
1237 struct ieee80211_local
*local
= sdata
->local
;
1240 mutex_lock(&local
->mtx
);
1242 if (rcu_access_pointer(local
->sched_scan_sdata
)) {
1243 mutex_unlock(&local
->mtx
);
1247 ret
= __ieee80211_request_sched_scan_start(sdata
, req
);
1249 mutex_unlock(&local
->mtx
);
1253 int ieee80211_request_sched_scan_stop(struct ieee80211_local
*local
)
1255 struct ieee80211_sub_if_data
*sched_scan_sdata
;
1258 mutex_lock(&local
->mtx
);
1260 if (!local
->ops
->sched_scan_stop
) {
1265 /* We don't want to restart sched scan anymore. */
1266 RCU_INIT_POINTER(local
->sched_scan_req
, NULL
);
1268 sched_scan_sdata
= rcu_dereference_protected(local
->sched_scan_sdata
,
1269 lockdep_is_held(&local
->mtx
));
1270 if (sched_scan_sdata
) {
1271 ret
= drv_sched_scan_stop(local
, sched_scan_sdata
);
1273 RCU_INIT_POINTER(local
->sched_scan_sdata
, NULL
);
1276 mutex_unlock(&local
->mtx
);
1281 void ieee80211_sched_scan_results(struct ieee80211_hw
*hw
)
1283 struct ieee80211_local
*local
= hw_to_local(hw
);
1285 trace_api_sched_scan_results(local
);
1287 cfg80211_sched_scan_results(hw
->wiphy
, 0);
1289 EXPORT_SYMBOL(ieee80211_sched_scan_results
);
1291 void ieee80211_sched_scan_end(struct ieee80211_local
*local
)
1293 mutex_lock(&local
->mtx
);
1295 if (!rcu_access_pointer(local
->sched_scan_sdata
)) {
1296 mutex_unlock(&local
->mtx
);
1300 RCU_INIT_POINTER(local
->sched_scan_sdata
, NULL
);
1302 /* If sched scan was aborted by the driver. */
1303 RCU_INIT_POINTER(local
->sched_scan_req
, NULL
);
1305 mutex_unlock(&local
->mtx
);
1307 cfg80211_sched_scan_stopped(local
->hw
.wiphy
, 0);
1310 void ieee80211_sched_scan_stopped_work(struct work_struct
*work
)
1312 struct ieee80211_local
*local
=
1313 container_of(work
, struct ieee80211_local
,
1314 sched_scan_stopped_work
);
1316 ieee80211_sched_scan_end(local
);
1319 void ieee80211_sched_scan_stopped(struct ieee80211_hw
*hw
)
1321 struct ieee80211_local
*local
= hw_to_local(hw
);
1323 trace_api_sched_scan_stopped(local
);
1326 * this shouldn't really happen, so for simplicity
1327 * simply ignore it, and let mac80211 reconfigure
1328 * the sched scan later on.
1330 if (local
->in_reconfig
)
1333 schedule_work(&local
->sched_scan_stopped_work
);
1335 EXPORT_SYMBOL(ieee80211_sched_scan_stopped
);