1 // SPDX-License-Identifier: GPL-2.0-only
3 * Scanning implementation
5 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
6 * Copyright 2004, Instant802 Networks, Inc.
7 * Copyright 2005, Devicescape Software, Inc.
8 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
9 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
10 * Copyright 2013-2015 Intel Mobile Communications GmbH
11 * Copyright 2016-2017 Intel Deutschland GmbH
12 * Copyright (C) 2018-2020 Intel Corporation
15 #include <linux/if_arp.h>
16 #include <linux/etherdevice.h>
17 #include <linux/rtnetlink.h>
18 #include <net/sch_generic.h>
19 #include <linux/slab.h>
20 #include <linux/export.h>
21 #include <linux/random.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
;
59 ieee80211_update_bss_from_elems(struct ieee80211_local
*local
,
60 struct ieee80211_bss
*bss
,
61 struct ieee802_11_elems
*elems
,
62 struct ieee80211_rx_status
*rx_status
,
68 bss
->device_ts_beacon
= rx_status
->device_timestamp
;
70 bss
->device_ts_presp
= rx_status
->device_timestamp
;
72 if (elems
->parse_error
) {
74 bss
->corrupt_data
|= IEEE80211_BSS_CORRUPT_BEACON
;
76 bss
->corrupt_data
|= IEEE80211_BSS_CORRUPT_PROBE_RESP
;
79 bss
->corrupt_data
&= ~IEEE80211_BSS_CORRUPT_BEACON
;
81 bss
->corrupt_data
&= ~IEEE80211_BSS_CORRUPT_PROBE_RESP
;
84 /* save the ERP value so that it is available at association time */
85 if (elems
->erp_info
&& (!elems
->parse_error
||
86 !(bss
->valid_data
& IEEE80211_BSS_VALID_ERP
))) {
87 bss
->erp_value
= elems
->erp_info
[0];
88 bss
->has_erp_value
= true;
89 if (!elems
->parse_error
)
90 bss
->valid_data
|= IEEE80211_BSS_VALID_ERP
;
93 /* replace old supported rates if we get new values */
94 if (!elems
->parse_error
||
95 !(bss
->valid_data
& IEEE80211_BSS_VALID_RATES
)) {
97 if (elems
->supp_rates
) {
98 clen
= IEEE80211_MAX_SUPP_RATES
;
99 if (clen
> elems
->supp_rates_len
)
100 clen
= elems
->supp_rates_len
;
101 memcpy(bss
->supp_rates
, elems
->supp_rates
, clen
);
104 if (elems
->ext_supp_rates
) {
105 clen
= IEEE80211_MAX_SUPP_RATES
- srlen
;
106 if (clen
> elems
->ext_supp_rates_len
)
107 clen
= elems
->ext_supp_rates_len
;
108 memcpy(bss
->supp_rates
+ srlen
, elems
->ext_supp_rates
,
113 bss
->supp_rates_len
= srlen
;
114 if (!elems
->parse_error
)
115 bss
->valid_data
|= IEEE80211_BSS_VALID_RATES
;
119 if (!elems
->parse_error
||
120 !(bss
->valid_data
& IEEE80211_BSS_VALID_WMM
)) {
121 bss
->wmm_used
= elems
->wmm_param
|| elems
->wmm_info
;
122 bss
->uapsd_supported
= is_uapsd_supported(elems
);
123 if (!elems
->parse_error
)
124 bss
->valid_data
|= IEEE80211_BSS_VALID_WMM
;
128 struct ieee80211_supported_band
*sband
=
129 local
->hw
.wiphy
->bands
[rx_status
->band
];
130 if (!(rx_status
->encoding
== RX_ENC_HT
) &&
131 !(rx_status
->encoding
== RX_ENC_VHT
))
133 &sband
->bitrates
[rx_status
->rate_idx
];
136 if (elems
->vht_cap_elem
)
138 le32_to_cpu(elems
->vht_cap_elem
->vht_cap_info
);
140 bss
->vht_cap_info
= 0;
143 struct ieee80211_bss
*
144 ieee80211_bss_info_update(struct ieee80211_local
*local
,
145 struct ieee80211_rx_status
*rx_status
,
146 struct ieee80211_mgmt
*mgmt
, size_t len
,
147 struct ieee80211_channel
*channel
)
149 bool beacon
= ieee80211_is_beacon(mgmt
->frame_control
) ||
150 ieee80211_is_s1g_beacon(mgmt
->frame_control
);
151 struct cfg80211_bss
*cbss
, *non_tx_cbss
;
152 struct ieee80211_bss
*bss
, *non_tx_bss
;
153 struct cfg80211_inform_bss bss_meta
= {
154 .boottime_ns
= rx_status
->boottime_ns
,
157 struct ieee80211_sub_if_data
*scan_sdata
;
158 struct ieee802_11_elems elems
;
162 if (rx_status
->flag
& RX_FLAG_NO_SIGNAL_VAL
)
163 bss_meta
.signal
= 0; /* invalid signal indication */
164 else if (ieee80211_hw_check(&local
->hw
, SIGNAL_DBM
))
165 bss_meta
.signal
= rx_status
->signal
* 100;
166 else if (ieee80211_hw_check(&local
->hw
, SIGNAL_UNSPEC
))
167 bss_meta
.signal
= (rx_status
->signal
* 100) / local
->hw
.max_signal
;
169 bss_meta
.scan_width
= NL80211_BSS_CHAN_WIDTH_20
;
170 if (rx_status
->bw
== RATE_INFO_BW_5
)
171 bss_meta
.scan_width
= NL80211_BSS_CHAN_WIDTH_5
;
172 else if (rx_status
->bw
== RATE_INFO_BW_10
)
173 bss_meta
.scan_width
= NL80211_BSS_CHAN_WIDTH_10
;
175 bss_meta
.chan
= channel
;
178 scan_sdata
= rcu_dereference(local
->scan_sdata
);
179 if (scan_sdata
&& scan_sdata
->vif
.type
== NL80211_IFTYPE_STATION
&&
180 scan_sdata
->vif
.bss_conf
.assoc
&&
181 ieee80211_have_rx_timestamp(rx_status
)) {
182 bss_meta
.parent_tsf
=
183 ieee80211_calculate_rx_timestamp(local
, rx_status
,
185 ether_addr_copy(bss_meta
.parent_bssid
,
186 scan_sdata
->vif
.bss_conf
.bssid
);
190 cbss
= cfg80211_inform_bss_frame_data(local
->hw
.wiphy
, &bss_meta
,
191 mgmt
, len
, GFP_ATOMIC
);
195 if (ieee80211_is_probe_resp(mgmt
->frame_control
)) {
196 elements
= mgmt
->u
.probe_resp
.variable
;
197 baselen
= offsetof(struct ieee80211_mgmt
,
198 u
.probe_resp
.variable
);
199 } else if (ieee80211_is_s1g_beacon(mgmt
->frame_control
)) {
200 struct ieee80211_ext
*ext
= (void *) mgmt
;
202 baselen
= offsetof(struct ieee80211_ext
, u
.s1g_beacon
.variable
);
203 elements
= ext
->u
.s1g_beacon
.variable
;
205 baselen
= offsetof(struct ieee80211_mgmt
, u
.beacon
.variable
);
206 elements
= mgmt
->u
.beacon
.variable
;
212 ieee802_11_parse_elems(elements
, len
- baselen
, false, &elems
,
213 mgmt
->bssid
, cbss
->bssid
);
215 /* In case the signal is invalid update the status */
216 signal_valid
= channel
== cbss
->channel
;
218 rx_status
->flag
|= RX_FLAG_NO_SIGNAL_VAL
;
220 bss
= (void *)cbss
->priv
;
221 ieee80211_update_bss_from_elems(local
, bss
, &elems
, rx_status
, beacon
);
223 list_for_each_entry(non_tx_cbss
, &cbss
->nontrans_list
, nontrans_list
) {
224 non_tx_bss
= (void *)non_tx_cbss
->priv
;
226 ieee80211_update_bss_from_elems(local
, non_tx_bss
, &elems
,
233 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data
*sdata
,
234 u32 scan_flags
, const u8
*da
)
238 /* accept broadcast for OCE */
239 if (scan_flags
& NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP
&&
240 is_broadcast_ether_addr(da
))
242 if (scan_flags
& NL80211_SCAN_FLAG_RANDOM_ADDR
)
244 return ether_addr_equal(da
, sdata
->vif
.addr
);
247 void ieee80211_scan_rx(struct ieee80211_local
*local
, struct sk_buff
*skb
)
249 struct ieee80211_rx_status
*rx_status
= IEEE80211_SKB_RXCB(skb
);
250 struct ieee80211_sub_if_data
*sdata1
, *sdata2
;
251 struct ieee80211_mgmt
*mgmt
= (void *)skb
->data
;
252 struct ieee80211_bss
*bss
;
253 struct ieee80211_channel
*channel
;
255 if (ieee80211_is_s1g_beacon(mgmt
->frame_control
)) {
258 } else if (skb
->len
< 24 ||
259 (!ieee80211_is_probe_resp(mgmt
->frame_control
) &&
260 !ieee80211_is_beacon(mgmt
->frame_control
)))
263 sdata1
= rcu_dereference(local
->scan_sdata
);
264 sdata2
= rcu_dereference(local
->sched_scan_sdata
);
266 if (likely(!sdata1
&& !sdata2
))
269 if (ieee80211_is_probe_resp(mgmt
->frame_control
)) {
270 struct cfg80211_scan_request
*scan_req
;
271 struct cfg80211_sched_scan_request
*sched_scan_req
;
272 u32 scan_req_flags
= 0, sched_scan_req_flags
= 0;
274 scan_req
= rcu_dereference(local
->scan_req
);
275 sched_scan_req
= rcu_dereference(local
->sched_scan_req
);
278 scan_req_flags
= scan_req
->flags
;
281 sched_scan_req_flags
= sched_scan_req
->flags
;
283 /* ignore ProbeResp to foreign address or non-bcast (OCE)
284 * unless scanning with randomised address
286 if (!ieee80211_scan_accept_presp(sdata1
, scan_req_flags
,
288 !ieee80211_scan_accept_presp(sdata2
, sched_scan_req_flags
,
293 channel
= ieee80211_get_channel_khz(local
->hw
.wiphy
,
294 ieee80211_rx_status_to_khz(rx_status
));
296 if (!channel
|| channel
->flags
& IEEE80211_CHAN_DISABLED
)
299 bss
= ieee80211_bss_info_update(local
, rx_status
,
303 ieee80211_rx_bss_put(local
, bss
);
307 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def
*chandef
,
308 enum nl80211_bss_scan_width scan_width
)
310 memset(chandef
, 0, sizeof(*chandef
));
311 switch (scan_width
) {
312 case NL80211_BSS_CHAN_WIDTH_5
:
313 chandef
->width
= NL80211_CHAN_WIDTH_5
;
315 case NL80211_BSS_CHAN_WIDTH_10
:
316 chandef
->width
= NL80211_CHAN_WIDTH_10
;
319 chandef
->width
= NL80211_CHAN_WIDTH_20_NOHT
;
324 /* return false if no more work */
325 static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data
*sdata
)
327 struct ieee80211_local
*local
= sdata
->local
;
328 struct cfg80211_scan_request
*req
;
329 struct cfg80211_chan_def chandef
;
331 int i
, ielen
, n_chans
;
334 req
= rcu_dereference_protected(local
->scan_req
,
335 lockdep_is_held(&local
->mtx
));
337 if (test_bit(SCAN_HW_CANCELLED
, &local
->scanning
))
340 if (ieee80211_hw_check(&local
->hw
, SINGLE_SCAN_ON_ALL_BANDS
)) {
341 for (i
= 0; i
< req
->n_channels
; i
++) {
342 local
->hw_scan_req
->req
.channels
[i
] = req
->channels
[i
];
343 bands_used
|= BIT(req
->channels
[i
]->band
);
346 n_chans
= req
->n_channels
;
349 if (local
->hw_scan_band
== NUM_NL80211_BANDS
)
354 for (i
= 0; i
< req
->n_channels
; i
++) {
355 if (req
->channels
[i
]->band
!=
358 local
->hw_scan_req
->req
.channels
[n_chans
] =
361 bands_used
|= BIT(req
->channels
[i
]->band
);
364 local
->hw_scan_band
++;
368 local
->hw_scan_req
->req
.n_channels
= n_chans
;
369 ieee80211_prepare_scan_chandef(&chandef
, req
->scan_width
);
371 if (req
->flags
& NL80211_SCAN_FLAG_MIN_PREQ_CONTENT
)
372 flags
|= IEEE80211_PROBE_FLAG_MIN_CONTENT
;
374 ielen
= ieee80211_build_preq_ies(sdata
,
375 (u8
*)local
->hw_scan_req
->req
.ie
,
376 local
->hw_scan_ies_bufsize
,
377 &local
->hw_scan_req
->ies
,
378 req
->ie
, req
->ie_len
,
379 bands_used
, req
->rates
, &chandef
,
381 local
->hw_scan_req
->req
.ie_len
= ielen
;
382 local
->hw_scan_req
->req
.no_cck
= req
->no_cck
;
383 ether_addr_copy(local
->hw_scan_req
->req
.mac_addr
, req
->mac_addr
);
384 ether_addr_copy(local
->hw_scan_req
->req
.mac_addr_mask
,
386 ether_addr_copy(local
->hw_scan_req
->req
.bssid
, req
->bssid
);
391 static void __ieee80211_scan_completed(struct ieee80211_hw
*hw
, bool aborted
)
393 struct ieee80211_local
*local
= hw_to_local(hw
);
394 bool hw_scan
= test_bit(SCAN_HW_SCANNING
, &local
->scanning
);
395 bool was_scanning
= local
->scanning
;
396 struct cfg80211_scan_request
*scan_req
;
397 struct ieee80211_sub_if_data
*scan_sdata
;
398 struct ieee80211_sub_if_data
*sdata
;
400 lockdep_assert_held(&local
->mtx
);
403 * It's ok to abort a not-yet-running scan (that
404 * we have one at all will be verified by checking
405 * local->scan_req next), but not to complete it
408 if (WARN_ON(!local
->scanning
&& !aborted
))
411 if (WARN_ON(!local
->scan_req
))
414 scan_sdata
= rcu_dereference_protected(local
->scan_sdata
,
415 lockdep_is_held(&local
->mtx
));
417 if (hw_scan
&& !aborted
&&
418 !ieee80211_hw_check(&local
->hw
, SINGLE_SCAN_ON_ALL_BANDS
) &&
419 ieee80211_prep_hw_scan(scan_sdata
)) {
422 rc
= drv_hw_scan(local
,
423 rcu_dereference_protected(local
->scan_sdata
,
424 lockdep_is_held(&local
->mtx
)),
430 /* HW scan failed and is going to be reported as aborted,
431 * so clear old scan info.
433 memset(&local
->scan_info
, 0, sizeof(local
->scan_info
));
437 kfree(local
->hw_scan_req
);
438 local
->hw_scan_req
= NULL
;
440 scan_req
= rcu_dereference_protected(local
->scan_req
,
441 lockdep_is_held(&local
->mtx
));
443 if (scan_req
!= local
->int_scan_req
) {
444 local
->scan_info
.aborted
= aborted
;
445 cfg80211_scan_done(scan_req
, &local
->scan_info
);
447 RCU_INIT_POINTER(local
->scan_req
, NULL
);
448 RCU_INIT_POINTER(local
->scan_sdata
, NULL
);
451 local
->scan_chandef
.chan
= NULL
;
453 /* Set power back to normal operating levels. */
454 ieee80211_hw_config(local
, 0);
457 ieee80211_configure_filter(local
);
458 drv_sw_scan_complete(local
, scan_sdata
);
459 ieee80211_offchannel_return(local
);
462 ieee80211_recalc_idle(local
);
464 ieee80211_mlme_notify_scan_completed(local
);
465 ieee80211_ibss_notify_scan_completed(local
);
467 /* Requeue all the work that might have been ignored while
468 * the scan was in progress; if there was none this will
469 * just be a no-op for the particular interface.
471 list_for_each_entry_rcu(sdata
, &local
->interfaces
, list
) {
472 if (ieee80211_sdata_running(sdata
))
473 ieee80211_queue_work(&sdata
->local
->hw
, &sdata
->work
);
477 ieee80211_start_next_roc(local
);
480 void ieee80211_scan_completed(struct ieee80211_hw
*hw
,
481 struct cfg80211_scan_info
*info
)
483 struct ieee80211_local
*local
= hw_to_local(hw
);
485 trace_api_scan_completed(local
, info
->aborted
);
487 set_bit(SCAN_COMPLETED
, &local
->scanning
);
489 set_bit(SCAN_ABORTED
, &local
->scanning
);
491 memcpy(&local
->scan_info
, info
, sizeof(*info
));
493 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
, 0);
495 EXPORT_SYMBOL(ieee80211_scan_completed
);
497 static int ieee80211_start_sw_scan(struct ieee80211_local
*local
,
498 struct ieee80211_sub_if_data
*sdata
)
500 /* Software scan is not supported in multi-channel cases */
501 if (local
->use_chanctx
)
505 * Hardware/driver doesn't support hw_scan, so use software
506 * scanning instead. First send a nullfunc frame with power save
507 * bit on so that AP will buffer the frames for us while we are not
508 * listening, then send probe requests to each channel and wait for
509 * the responses. After all channels are scanned, tune back to the
510 * original channel and send a nullfunc frame with power save bit
511 * off to trigger the AP to send us all the buffered frames.
513 * Note that while local->sw_scanning is true everything else but
514 * nullfunc frames and probe requests will be dropped in
515 * ieee80211_tx_h_check_assoc().
517 drv_sw_scan_start(local
, sdata
, local
->scan_addr
);
519 local
->leave_oper_channel_time
= jiffies
;
520 local
->next_scan_state
= SCAN_DECISION
;
521 local
->scan_channel_idx
= 0;
523 ieee80211_offchannel_stop_vifs(local
);
525 /* ensure nullfunc is transmitted before leaving operating channel */
526 ieee80211_flush_queues(local
, NULL
, false);
528 ieee80211_configure_filter(local
);
530 /* We need to set power level at maximum rate for scanning. */
531 ieee80211_hw_config(local
, 0);
533 ieee80211_queue_delayed_work(&local
->hw
,
534 &local
->scan_work
, 0);
539 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data
*sdata
)
541 struct ieee80211_local
*local
= sdata
->local
;
542 struct ieee80211_sub_if_data
*sdata_iter
;
544 if (!ieee80211_is_radar_required(local
))
547 if (!regulatory_pre_cac_allowed(local
->hw
.wiphy
))
550 mutex_lock(&local
->iflist_mtx
);
551 list_for_each_entry(sdata_iter
, &local
->interfaces
, list
) {
552 if (sdata_iter
->wdev
.cac_started
) {
553 mutex_unlock(&local
->iflist_mtx
);
557 mutex_unlock(&local
->iflist_mtx
);
562 static bool ieee80211_can_scan(struct ieee80211_local
*local
,
563 struct ieee80211_sub_if_data
*sdata
)
565 if (!__ieee80211_can_leave_ch(sdata
))
568 if (!list_empty(&local
->roc_list
))
571 if (sdata
->vif
.type
== NL80211_IFTYPE_STATION
&&
572 sdata
->u
.mgd
.flags
& IEEE80211_STA_CONNECTION_POLL
)
578 void ieee80211_run_deferred_scan(struct ieee80211_local
*local
)
580 lockdep_assert_held(&local
->mtx
);
582 if (!local
->scan_req
|| local
->scanning
)
585 if (!ieee80211_can_scan(local
,
586 rcu_dereference_protected(
588 lockdep_is_held(&local
->mtx
))))
591 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
,
592 round_jiffies_relative(0));
595 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data
*sdata
,
596 const u8
*src
, const u8
*dst
,
597 const u8
*ssid
, size_t ssid_len
,
598 const u8
*ie
, size_t ie_len
,
599 u32 ratemask
, u32 flags
, u32 tx_flags
,
600 struct ieee80211_channel
*channel
)
604 skb
= ieee80211_build_probe_req(sdata
, src
, dst
, ratemask
, channel
,
609 if (flags
& IEEE80211_PROBE_FLAG_RANDOM_SN
) {
610 struct ieee80211_hdr
*hdr
= (void *)skb
->data
;
611 struct ieee80211_tx_info
*info
= IEEE80211_SKB_CB(skb
);
612 u16 sn
= get_random_u32();
614 info
->control
.flags
|= IEEE80211_TX_CTRL_NO_SEQNO
;
616 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn
));
618 IEEE80211_SKB_CB(skb
)->flags
|= tx_flags
;
619 ieee80211_tx_skb_tid_band(sdata
, skb
, 7, channel
->band
);
623 static void ieee80211_scan_state_send_probe(struct ieee80211_local
*local
,
624 unsigned long *next_delay
)
627 struct ieee80211_sub_if_data
*sdata
;
628 struct cfg80211_scan_request
*scan_req
;
629 enum nl80211_band band
= local
->hw
.conf
.chandef
.chan
->band
;
630 u32 flags
= 0, tx_flags
;
632 scan_req
= rcu_dereference_protected(local
->scan_req
,
633 lockdep_is_held(&local
->mtx
));
635 tx_flags
= IEEE80211_TX_INTFL_OFFCHAN_TX_OK
;
636 if (scan_req
->no_cck
)
637 tx_flags
|= IEEE80211_TX_CTL_NO_CCK_RATE
;
638 if (scan_req
->flags
& NL80211_SCAN_FLAG_MIN_PREQ_CONTENT
)
639 flags
|= IEEE80211_PROBE_FLAG_MIN_CONTENT
;
640 if (scan_req
->flags
& NL80211_SCAN_FLAG_RANDOM_SN
)
641 flags
|= IEEE80211_PROBE_FLAG_RANDOM_SN
;
643 sdata
= rcu_dereference_protected(local
->scan_sdata
,
644 lockdep_is_held(&local
->mtx
));
646 for (i
= 0; i
< scan_req
->n_ssids
; i
++)
647 ieee80211_send_scan_probe_req(
648 sdata
, local
->scan_addr
, scan_req
->bssid
,
649 scan_req
->ssids
[i
].ssid
, scan_req
->ssids
[i
].ssid_len
,
650 scan_req
->ie
, scan_req
->ie_len
,
651 scan_req
->rates
[band
], flags
,
652 tx_flags
, local
->hw
.conf
.chandef
.chan
);
655 * After sending probe requests, wait for probe responses
658 *next_delay
= IEEE80211_CHANNEL_TIME
;
659 local
->next_scan_state
= SCAN_DECISION
;
662 static int __ieee80211_start_scan(struct ieee80211_sub_if_data
*sdata
,
663 struct cfg80211_scan_request
*req
)
665 struct ieee80211_local
*local
= sdata
->local
;
666 bool hw_scan
= local
->ops
->hw_scan
;
669 lockdep_assert_held(&local
->mtx
);
674 if (!__ieee80211_can_leave_ch(sdata
))
677 if (!ieee80211_can_scan(local
, sdata
)) {
678 /* wait for the work to finish/time out */
679 rcu_assign_pointer(local
->scan_req
, req
);
680 rcu_assign_pointer(local
->scan_sdata
, sdata
);
688 local
->hw_scan_ies_bufsize
= local
->scan_ies_len
+ req
->ie_len
;
690 if (ieee80211_hw_check(&local
->hw
, SINGLE_SCAN_ON_ALL_BANDS
)) {
692 u8 bands_counted
= 0;
694 for (i
= 0; i
< req
->n_channels
; i
++) {
695 if (bands_counted
& BIT(req
->channels
[i
]->band
))
697 bands_counted
|= BIT(req
->channels
[i
]->band
);
701 local
->hw_scan_ies_bufsize
*= n_bands
;
704 local
->hw_scan_req
= kmalloc(
705 sizeof(*local
->hw_scan_req
) +
706 req
->n_channels
* sizeof(req
->channels
[0]) +
707 local
->hw_scan_ies_bufsize
, GFP_KERNEL
);
708 if (!local
->hw_scan_req
)
711 local
->hw_scan_req
->req
.ssids
= req
->ssids
;
712 local
->hw_scan_req
->req
.n_ssids
= req
->n_ssids
;
713 ies
= (u8
*)local
->hw_scan_req
+
714 sizeof(*local
->hw_scan_req
) +
715 req
->n_channels
* sizeof(req
->channels
[0]);
716 local
->hw_scan_req
->req
.ie
= ies
;
717 local
->hw_scan_req
->req
.flags
= req
->flags
;
718 eth_broadcast_addr(local
->hw_scan_req
->req
.bssid
);
719 local
->hw_scan_req
->req
.duration
= req
->duration
;
720 local
->hw_scan_req
->req
.duration_mandatory
=
721 req
->duration_mandatory
;
723 local
->hw_scan_band
= 0;
724 local
->hw_scan_req
->req
.n_6ghz_params
= req
->n_6ghz_params
;
725 local
->hw_scan_req
->req
.scan_6ghz_params
=
726 req
->scan_6ghz_params
;
727 local
->hw_scan_req
->req
.scan_6ghz
= req
->scan_6ghz
;
730 * After allocating local->hw_scan_req, we must
731 * go through until ieee80211_prep_hw_scan(), so
732 * anything that might be changed here and leave
733 * this function early must not go after this
738 rcu_assign_pointer(local
->scan_req
, req
);
739 rcu_assign_pointer(local
->scan_sdata
, sdata
);
741 if (req
->flags
& NL80211_SCAN_FLAG_RANDOM_ADDR
)
742 get_random_mask_addr(local
->scan_addr
,
746 memcpy(local
->scan_addr
, sdata
->vif
.addr
, ETH_ALEN
);
749 __set_bit(SCAN_HW_SCANNING
, &local
->scanning
);
750 } else if ((req
->n_channels
== 1) &&
751 (req
->channels
[0] == local
->_oper_chandef
.chan
)) {
753 * If we are scanning only on the operating channel
754 * then we do not need to stop normal activities
756 unsigned long next_delay
;
758 __set_bit(SCAN_ONCHANNEL_SCANNING
, &local
->scanning
);
760 ieee80211_recalc_idle(local
);
762 /* Notify driver scan is starting, keep order of operations
763 * same as normal software scan, in case that matters. */
764 drv_sw_scan_start(local
, sdata
, local
->scan_addr
);
766 ieee80211_configure_filter(local
); /* accept probe-responses */
768 /* We need to ensure power level is at max for scanning. */
769 ieee80211_hw_config(local
, 0);
771 if ((req
->channels
[0]->flags
& (IEEE80211_CHAN_NO_IR
|
772 IEEE80211_CHAN_RADAR
)) ||
774 next_delay
= IEEE80211_PASSIVE_CHANNEL_TIME
;
776 ieee80211_scan_state_send_probe(local
, &next_delay
);
777 next_delay
= IEEE80211_CHANNEL_TIME
;
780 /* Now, just wait a bit and we are all done! */
781 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
,
785 /* Do normal software scan */
786 __set_bit(SCAN_SW_SCANNING
, &local
->scanning
);
789 ieee80211_recalc_idle(local
);
792 WARN_ON(!ieee80211_prep_hw_scan(sdata
));
793 rc
= drv_hw_scan(local
, sdata
, local
->hw_scan_req
);
795 rc
= ieee80211_start_sw_scan(local
, sdata
);
799 kfree(local
->hw_scan_req
);
800 local
->hw_scan_req
= NULL
;
803 ieee80211_recalc_idle(local
);
805 local
->scan_req
= NULL
;
806 RCU_INIT_POINTER(local
->scan_sdata
, NULL
);
809 if (hw_scan
&& rc
== 1) {
811 * we can't fall back to software for P2P-GO
812 * as it must update NoA etc.
814 if (ieee80211_vif_type_p2p(&sdata
->vif
) ==
815 NL80211_IFTYPE_P2P_GO
)
825 ieee80211_scan_get_channel_time(struct ieee80211_channel
*chan
)
828 * TODO: channel switching also consumes quite some time,
829 * add that delay as well to get a better estimation
831 if (chan
->flags
& (IEEE80211_CHAN_NO_IR
| IEEE80211_CHAN_RADAR
))
832 return IEEE80211_PASSIVE_CHANNEL_TIME
;
833 return IEEE80211_PROBE_DELAY
+ IEEE80211_CHANNEL_TIME
;
836 static void ieee80211_scan_state_decision(struct ieee80211_local
*local
,
837 unsigned long *next_delay
)
839 bool associated
= false;
840 bool tx_empty
= true;
842 struct ieee80211_sub_if_data
*sdata
;
843 struct ieee80211_channel
*next_chan
;
844 enum mac80211_scan_state next_scan_state
;
845 struct cfg80211_scan_request
*scan_req
;
848 * check if at least one STA interface is associated,
849 * check if at least one STA interface has pending tx frames
850 * and grab the lowest used beacon interval
852 mutex_lock(&local
->iflist_mtx
);
853 list_for_each_entry(sdata
, &local
->interfaces
, list
) {
854 if (!ieee80211_sdata_running(sdata
))
857 if (sdata
->vif
.type
== NL80211_IFTYPE_STATION
) {
858 if (sdata
->u
.mgd
.associated
) {
861 if (!qdisc_all_tx_empty(sdata
->dev
)) {
868 mutex_unlock(&local
->iflist_mtx
);
870 scan_req
= rcu_dereference_protected(local
->scan_req
,
871 lockdep_is_held(&local
->mtx
));
873 next_chan
= scan_req
->channels
[local
->scan_channel_idx
];
876 * we're currently scanning a different channel, let's
877 * see if we can scan another channel without interfering
878 * with the current traffic situation.
880 * Keep good latency, do not stay off-channel more than 125 ms.
883 bad_latency
= time_after(jiffies
+
884 ieee80211_scan_get_channel_time(next_chan
),
885 local
->leave_oper_channel_time
+ HZ
/ 8);
887 if (associated
&& !tx_empty
) {
888 if (scan_req
->flags
& NL80211_SCAN_FLAG_LOW_PRIORITY
)
889 next_scan_state
= SCAN_ABORT
;
891 next_scan_state
= SCAN_SUSPEND
;
892 } else if (associated
&& bad_latency
) {
893 next_scan_state
= SCAN_SUSPEND
;
895 next_scan_state
= SCAN_SET_CHANNEL
;
898 local
->next_scan_state
= next_scan_state
;
903 static void ieee80211_scan_state_set_channel(struct ieee80211_local
*local
,
904 unsigned long *next_delay
)
907 struct ieee80211_channel
*chan
;
908 enum nl80211_bss_scan_width oper_scan_width
;
909 struct cfg80211_scan_request
*scan_req
;
911 scan_req
= rcu_dereference_protected(local
->scan_req
,
912 lockdep_is_held(&local
->mtx
));
915 chan
= scan_req
->channels
[local
->scan_channel_idx
];
917 local
->scan_chandef
.chan
= chan
;
918 local
->scan_chandef
.center_freq1
= chan
->center_freq
;
919 local
->scan_chandef
.freq1_offset
= chan
->freq_offset
;
920 local
->scan_chandef
.center_freq2
= 0;
922 /* For scanning on the S1G band, ignore scan_width (which is constant
923 * across all channels) for now since channel width is specific to each
924 * channel. Detect the required channel width here and likely revisit
925 * later. Maybe scan_width could be used to build the channel scan list?
927 if (chan
->band
== NL80211_BAND_S1GHZ
) {
928 local
->scan_chandef
.width
= ieee80211_s1g_channel_width(chan
);
932 switch (scan_req
->scan_width
) {
933 case NL80211_BSS_CHAN_WIDTH_5
:
934 local
->scan_chandef
.width
= NL80211_CHAN_WIDTH_5
;
936 case NL80211_BSS_CHAN_WIDTH_10
:
937 local
->scan_chandef
.width
= NL80211_CHAN_WIDTH_10
;
940 case NL80211_BSS_CHAN_WIDTH_20
:
941 /* If scanning on oper channel, use whatever channel-type
942 * is currently in use.
944 oper_scan_width
= cfg80211_chandef_to_scan_width(
945 &local
->_oper_chandef
);
946 if (chan
== local
->_oper_chandef
.chan
&&
947 oper_scan_width
== scan_req
->scan_width
)
948 local
->scan_chandef
= local
->_oper_chandef
;
950 local
->scan_chandef
.width
= NL80211_CHAN_WIDTH_20_NOHT
;
952 case NL80211_BSS_CHAN_WIDTH_1
:
953 case NL80211_BSS_CHAN_WIDTH_2
:
954 /* shouldn't get here, S1G handled above */
960 if (ieee80211_hw_config(local
, IEEE80211_CONF_CHANGE_CHANNEL
))
963 /* advance state machine to next channel/band */
964 local
->scan_channel_idx
++;
967 /* if we skip this channel return to the decision state */
968 local
->next_scan_state
= SCAN_DECISION
;
973 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
974 * (which unfortunately doesn't say _why_ step a) is done,
975 * but it waits for the probe delay or until a frame is
976 * received - and the received frame would update the NAV).
977 * For now, we do not support waiting until a frame is
980 * In any case, it is not necessary for a passive scan.
982 if ((chan
->flags
& (IEEE80211_CHAN_NO_IR
| IEEE80211_CHAN_RADAR
)) ||
983 !scan_req
->n_ssids
) {
984 *next_delay
= IEEE80211_PASSIVE_CHANNEL_TIME
;
985 local
->next_scan_state
= SCAN_DECISION
;
989 /* active scan, send probes */
990 *next_delay
= IEEE80211_PROBE_DELAY
;
991 local
->next_scan_state
= SCAN_SEND_PROBE
;
994 static void ieee80211_scan_state_suspend(struct ieee80211_local
*local
,
995 unsigned long *next_delay
)
997 /* switch back to the operating channel */
998 local
->scan_chandef
.chan
= NULL
;
999 ieee80211_hw_config(local
, IEEE80211_CONF_CHANGE_CHANNEL
);
1002 ieee80211_offchannel_return(local
);
1004 *next_delay
= HZ
/ 5;
1005 /* afterwards, resume scan & go to next channel */
1006 local
->next_scan_state
= SCAN_RESUME
;
1009 static void ieee80211_scan_state_resume(struct ieee80211_local
*local
,
1010 unsigned long *next_delay
)
1012 ieee80211_offchannel_stop_vifs(local
);
1014 if (local
->ops
->flush
) {
1015 ieee80211_flush_queues(local
, NULL
, false);
1018 *next_delay
= HZ
/ 10;
1020 /* remember when we left the operating channel */
1021 local
->leave_oper_channel_time
= jiffies
;
1023 /* advance to the next channel to be scanned */
1024 local
->next_scan_state
= SCAN_SET_CHANNEL
;
1027 void ieee80211_scan_work(struct work_struct
*work
)
1029 struct ieee80211_local
*local
=
1030 container_of(work
, struct ieee80211_local
, scan_work
.work
);
1031 struct ieee80211_sub_if_data
*sdata
;
1032 struct cfg80211_scan_request
*scan_req
;
1033 unsigned long next_delay
= 0;
1036 mutex_lock(&local
->mtx
);
1038 if (!ieee80211_can_run_worker(local
)) {
1043 sdata
= rcu_dereference_protected(local
->scan_sdata
,
1044 lockdep_is_held(&local
->mtx
));
1045 scan_req
= rcu_dereference_protected(local
->scan_req
,
1046 lockdep_is_held(&local
->mtx
));
1048 /* When scanning on-channel, the first-callback means completed. */
1049 if (test_bit(SCAN_ONCHANNEL_SCANNING
, &local
->scanning
)) {
1050 aborted
= test_and_clear_bit(SCAN_ABORTED
, &local
->scanning
);
1054 if (test_and_clear_bit(SCAN_COMPLETED
, &local
->scanning
)) {
1055 aborted
= test_and_clear_bit(SCAN_ABORTED
, &local
->scanning
);
1059 if (!sdata
|| !scan_req
)
1062 if (!local
->scanning
) {
1065 RCU_INIT_POINTER(local
->scan_req
, NULL
);
1066 RCU_INIT_POINTER(local
->scan_sdata
, NULL
);
1068 rc
= __ieee80211_start_scan(sdata
, scan_req
);
1070 /* need to complete scan in cfg80211 */
1071 rcu_assign_pointer(local
->scan_req
, scan_req
);
1079 * as long as no delay is required advance immediately
1080 * without scheduling a new work
1083 if (!ieee80211_sdata_running(sdata
)) {
1088 switch (local
->next_scan_state
) {
1090 /* if no more bands/channels left, complete scan */
1091 if (local
->scan_channel_idx
>= scan_req
->n_channels
) {
1095 ieee80211_scan_state_decision(local
, &next_delay
);
1097 case SCAN_SET_CHANNEL
:
1098 ieee80211_scan_state_set_channel(local
, &next_delay
);
1100 case SCAN_SEND_PROBE
:
1101 ieee80211_scan_state_send_probe(local
, &next_delay
);
1104 ieee80211_scan_state_suspend(local
, &next_delay
);
1107 ieee80211_scan_state_resume(local
, &next_delay
);
1113 } while (next_delay
== 0);
1115 ieee80211_queue_delayed_work(&local
->hw
, &local
->scan_work
, next_delay
);
1119 __ieee80211_scan_completed(&local
->hw
, aborted
);
1121 mutex_unlock(&local
->mtx
);
1124 int ieee80211_request_scan(struct ieee80211_sub_if_data
*sdata
,
1125 struct cfg80211_scan_request
*req
)
1129 mutex_lock(&sdata
->local
->mtx
);
1130 res
= __ieee80211_start_scan(sdata
, req
);
1131 mutex_unlock(&sdata
->local
->mtx
);
1136 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data
*sdata
,
1137 const u8
*ssid
, u8 ssid_len
,
1138 struct ieee80211_channel
**channels
,
1139 unsigned int n_channels
,
1140 enum nl80211_bss_scan_width scan_width
)
1142 struct ieee80211_local
*local
= sdata
->local
;
1143 int ret
= -EBUSY
, i
, n_ch
= 0;
1144 enum nl80211_band band
;
1146 mutex_lock(&local
->mtx
);
1149 if (local
->scan_req
)
1152 /* fill internal scan request */
1156 for (band
= 0; band
< NUM_NL80211_BANDS
; band
++) {
1157 if (!local
->hw
.wiphy
->bands
[band
] ||
1158 band
== NL80211_BAND_6GHZ
)
1161 max_n
= local
->hw
.wiphy
->bands
[band
]->n_channels
;
1162 for (i
= 0; i
< max_n
; i
++) {
1163 struct ieee80211_channel
*tmp_ch
=
1164 &local
->hw
.wiphy
->bands
[band
]->channels
[i
];
1166 if (tmp_ch
->flags
& (IEEE80211_CHAN_NO_IR
|
1167 IEEE80211_CHAN_DISABLED
))
1170 local
->int_scan_req
->channels
[n_ch
] = tmp_ch
;
1175 if (WARN_ON_ONCE(n_ch
== 0))
1178 local
->int_scan_req
->n_channels
= n_ch
;
1180 for (i
= 0; i
< n_channels
; i
++) {
1181 if (channels
[i
]->flags
& (IEEE80211_CHAN_NO_IR
|
1182 IEEE80211_CHAN_DISABLED
))
1185 local
->int_scan_req
->channels
[n_ch
] = channels
[i
];
1189 if (WARN_ON_ONCE(n_ch
== 0))
1192 local
->int_scan_req
->n_channels
= n_ch
;
1195 local
->int_scan_req
->ssids
= &local
->scan_ssid
;
1196 local
->int_scan_req
->n_ssids
= 1;
1197 local
->int_scan_req
->scan_width
= scan_width
;
1198 memcpy(local
->int_scan_req
->ssids
[0].ssid
, ssid
, IEEE80211_MAX_SSID_LEN
);
1199 local
->int_scan_req
->ssids
[0].ssid_len
= ssid_len
;
1201 ret
= __ieee80211_start_scan(sdata
, sdata
->local
->int_scan_req
);
1203 mutex_unlock(&local
->mtx
);
1208 * Only call this function when a scan can't be queued -- under RTNL.
1210 void ieee80211_scan_cancel(struct ieee80211_local
*local
)
1213 * We are canceling software scan, or deferred scan that was not
1214 * yet really started (see __ieee80211_start_scan ).
1216 * Regarding hardware scan:
1217 * - we can not call __ieee80211_scan_completed() as when
1218 * SCAN_HW_SCANNING bit is set this function change
1219 * local->hw_scan_req to operate on 5G band, what race with
1220 * driver which can use local->hw_scan_req
1222 * - we can not cancel scan_work since driver can schedule it
1223 * by ieee80211_scan_completed(..., true) to finish scan
1225 * Hence we only call the cancel_hw_scan() callback, but the low-level
1226 * driver is still responsible for calling ieee80211_scan_completed()
1227 * after the scan was completed/aborted.
1230 mutex_lock(&local
->mtx
);
1231 if (!local
->scan_req
)
1235 * We have a scan running and the driver already reported completion,
1236 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1239 if (test_bit(SCAN_HW_SCANNING
, &local
->scanning
) &&
1240 test_bit(SCAN_COMPLETED
, &local
->scanning
)) {
1241 set_bit(SCAN_HW_CANCELLED
, &local
->scanning
);
1245 if (test_bit(SCAN_HW_SCANNING
, &local
->scanning
)) {
1247 * Make sure that __ieee80211_scan_completed doesn't trigger a
1248 * scan on another band.
1250 set_bit(SCAN_HW_CANCELLED
, &local
->scanning
);
1251 if (local
->ops
->cancel_hw_scan
)
1252 drv_cancel_hw_scan(local
,
1253 rcu_dereference_protected(local
->scan_sdata
,
1254 lockdep_is_held(&local
->mtx
)));
1259 * If the work is currently running, it must be blocked on
1260 * the mutex, but we'll set scan_sdata = NULL and it'll
1261 * simply exit once it acquires the mutex.
1263 cancel_delayed_work(&local
->scan_work
);
1265 memset(&local
->scan_info
, 0, sizeof(local
->scan_info
));
1266 __ieee80211_scan_completed(&local
->hw
, true);
1268 mutex_unlock(&local
->mtx
);
1271 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data
*sdata
,
1272 struct cfg80211_sched_scan_request
*req
)
1274 struct ieee80211_local
*local
= sdata
->local
;
1275 struct ieee80211_scan_ies sched_scan_ies
= {};
1276 struct cfg80211_chan_def chandef
;
1277 int ret
, i
, iebufsz
, num_bands
= 0;
1278 u32 rate_masks
[NUM_NL80211_BANDS
] = {};
1283 iebufsz
= local
->scan_ies_len
+ req
->ie_len
;
1285 lockdep_assert_held(&local
->mtx
);
1287 if (!local
->ops
->sched_scan_start
)
1290 for (i
= 0; i
< NUM_NL80211_BANDS
; i
++) {
1291 if (local
->hw
.wiphy
->bands
[i
]) {
1292 bands_used
|= BIT(i
);
1293 rate_masks
[i
] = (u32
) -1;
1298 if (req
->flags
& NL80211_SCAN_FLAG_MIN_PREQ_CONTENT
)
1299 flags
|= IEEE80211_PROBE_FLAG_MIN_CONTENT
;
1301 ie
= kcalloc(iebufsz
, num_bands
, GFP_KERNEL
);
1307 ieee80211_prepare_scan_chandef(&chandef
, req
->scan_width
);
1309 ieee80211_build_preq_ies(sdata
, ie
, num_bands
* iebufsz
,
1310 &sched_scan_ies
, req
->ie
,
1311 req
->ie_len
, bands_used
, rate_masks
, &chandef
,
1314 ret
= drv_sched_scan_start(local
, sdata
, req
, &sched_scan_ies
);
1316 rcu_assign_pointer(local
->sched_scan_sdata
, sdata
);
1317 rcu_assign_pointer(local
->sched_scan_req
, req
);
1324 /* Clean in case of failure after HW restart or upon resume. */
1325 RCU_INIT_POINTER(local
->sched_scan_sdata
, NULL
);
1326 RCU_INIT_POINTER(local
->sched_scan_req
, NULL
);
1332 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data
*sdata
,
1333 struct cfg80211_sched_scan_request
*req
)
1335 struct ieee80211_local
*local
= sdata
->local
;
1338 mutex_lock(&local
->mtx
);
1340 if (rcu_access_pointer(local
->sched_scan_sdata
)) {
1341 mutex_unlock(&local
->mtx
);
1345 ret
= __ieee80211_request_sched_scan_start(sdata
, req
);
1347 mutex_unlock(&local
->mtx
);
1351 int ieee80211_request_sched_scan_stop(struct ieee80211_local
*local
)
1353 struct ieee80211_sub_if_data
*sched_scan_sdata
;
1356 mutex_lock(&local
->mtx
);
1358 if (!local
->ops
->sched_scan_stop
) {
1363 /* We don't want to restart sched scan anymore. */
1364 RCU_INIT_POINTER(local
->sched_scan_req
, NULL
);
1366 sched_scan_sdata
= rcu_dereference_protected(local
->sched_scan_sdata
,
1367 lockdep_is_held(&local
->mtx
));
1368 if (sched_scan_sdata
) {
1369 ret
= drv_sched_scan_stop(local
, sched_scan_sdata
);
1371 RCU_INIT_POINTER(local
->sched_scan_sdata
, NULL
);
1374 mutex_unlock(&local
->mtx
);
1379 void ieee80211_sched_scan_results(struct ieee80211_hw
*hw
)
1381 struct ieee80211_local
*local
= hw_to_local(hw
);
1383 trace_api_sched_scan_results(local
);
1385 cfg80211_sched_scan_results(hw
->wiphy
, 0);
1387 EXPORT_SYMBOL(ieee80211_sched_scan_results
);
1389 void ieee80211_sched_scan_end(struct ieee80211_local
*local
)
1391 mutex_lock(&local
->mtx
);
1393 if (!rcu_access_pointer(local
->sched_scan_sdata
)) {
1394 mutex_unlock(&local
->mtx
);
1398 RCU_INIT_POINTER(local
->sched_scan_sdata
, NULL
);
1400 /* If sched scan was aborted by the driver. */
1401 RCU_INIT_POINTER(local
->sched_scan_req
, NULL
);
1403 mutex_unlock(&local
->mtx
);
1405 cfg80211_sched_scan_stopped(local
->hw
.wiphy
, 0);
1408 void ieee80211_sched_scan_stopped_work(struct work_struct
*work
)
1410 struct ieee80211_local
*local
=
1411 container_of(work
, struct ieee80211_local
,
1412 sched_scan_stopped_work
);
1414 ieee80211_sched_scan_end(local
);
1417 void ieee80211_sched_scan_stopped(struct ieee80211_hw
*hw
)
1419 struct ieee80211_local
*local
= hw_to_local(hw
);
1421 trace_api_sched_scan_stopped(local
);
1424 * this shouldn't really happen, so for simplicity
1425 * simply ignore it, and let mac80211 reconfigure
1426 * the sched scan later on.
1428 if (local
->in_reconfig
)
1431 schedule_work(&local
->sched_scan_stopped_work
);
1433 EXPORT_SYMBOL(ieee80211_sched_scan_stopped
);