2 * Scanning implementation
5 * Copyright 2004, Instant802 Networks, Inc.
6 * Copyright 2005, Devicescape Software, Inc.
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 <net/mac80211.h>
25 #include "ieee80211_i.h"
26 #include "driver-ops.h"
29 #define IEEE80211_PROBE_DELAY (HZ / 33)
30 #define IEEE80211_CHANNEL_TIME (HZ / 33)
31 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
33 void ieee80211_rx_bss_put(struct ieee80211_local *local,
34 struct ieee80211_bss *bss)
38 cfg80211_put_bss(local->hw.wiphy,
39 container_of((void *)bss, struct cfg80211_bss, priv));
42 static bool is_uapsd_supported(struct ieee802_11_elems *elems)
46 if (elems->wmm_info && elems->wmm_info_len == 7
47 && elems->wmm_info[5] == 1)
48 qos_info = elems->wmm_info[6];
49 else if (elems->wmm_param && elems->wmm_param_len == 24
50 && elems->wmm_param[5] == 1)
51 qos_info = elems->wmm_param[6];
53 /* no valid wmm information or parameter element found */
56 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
59 struct ieee80211_bss *
60 ieee80211_bss_info_update(struct ieee80211_local *local,
61 struct ieee80211_rx_status *rx_status,
62 struct ieee80211_mgmt *mgmt, size_t len,
63 struct ieee802_11_elems *elems,
64 struct ieee80211_channel *channel)
66 bool beacon = ieee80211_is_beacon(mgmt->frame_control);
67 struct cfg80211_bss *cbss;
68 struct ieee80211_bss *bss;
70 struct cfg80211_inform_bss bss_meta = {
71 .boottime_ns = rx_status->boottime_ns,
74 struct ieee80211_sub_if_data *scan_sdata;
76 if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
77 bss_meta.signal = 0; /* invalid signal indication */
78 else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
79 bss_meta.signal = rx_status->signal * 100;
80 else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
81 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
83 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
84 if (rx_status->bw == RATE_INFO_BW_5)
85 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
86 else if (rx_status->bw == RATE_INFO_BW_10)
87 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
89 bss_meta.chan = channel;
92 scan_sdata = rcu_dereference(local->scan_sdata);
93 if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
94 scan_sdata->vif.bss_conf.assoc &&
95 ieee80211_have_rx_timestamp(rx_status)) {
97 ieee80211_calculate_rx_timestamp(local, rx_status,
99 ether_addr_copy(bss_meta.parent_bssid,
100 scan_sdata->vif.bss_conf.bssid);
104 cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
105 mgmt, len, GFP_ATOMIC);
108 /* In case the signal is invalid update the status */
109 signal_valid = abs(channel->center_freq - cbss->channel->center_freq)
110 <= local->hw.wiphy->max_adj_channel_rssi_comp;
112 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
114 bss = (void *)cbss->priv;
117 bss->device_ts_beacon = rx_status->device_timestamp;
119 bss->device_ts_presp = rx_status->device_timestamp;
121 if (elems->parse_error) {
123 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
125 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
128 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
130 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
133 /* save the ERP value so that it is available at association time */
134 if (elems->erp_info && (!elems->parse_error ||
135 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
136 bss->erp_value = elems->erp_info[0];
137 bss->has_erp_value = true;
138 if (!elems->parse_error)
139 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
142 /* replace old supported rates if we get new values */
143 if (!elems->parse_error ||
144 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
146 if (elems->supp_rates) {
147 clen = IEEE80211_MAX_SUPP_RATES;
148 if (clen > elems->supp_rates_len)
149 clen = elems->supp_rates_len;
150 memcpy(bss->supp_rates, elems->supp_rates, clen);
153 if (elems->ext_supp_rates) {
154 clen = IEEE80211_MAX_SUPP_RATES - srlen;
155 if (clen > elems->ext_supp_rates_len)
156 clen = elems->ext_supp_rates_len;
157 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
162 bss->supp_rates_len = srlen;
163 if (!elems->parse_error)
164 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
168 if (!elems->parse_error ||
169 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
170 bss->wmm_used = elems->wmm_param || elems->wmm_info;
171 bss->uapsd_supported = is_uapsd_supported(elems);
172 if (!elems->parse_error)
173 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
177 struct ieee80211_supported_band *sband =
178 local->hw.wiphy->bands[rx_status->band];
179 if (!(rx_status->encoding == RX_ENC_HT) &&
180 !(rx_status->encoding == RX_ENC_VHT))
182 &sband->bitrates[rx_status->rate_idx];
188 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
189 u32 scan_flags, const u8 *da)
193 /* accept broadcast for OCE */
194 if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
195 is_broadcast_ether_addr(da))
197 if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
199 return ether_addr_equal(da, sdata->vif.addr);
202 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
204 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
205 struct ieee80211_sub_if_data *sdata1, *sdata2;
206 struct ieee80211_mgmt *mgmt = (void *)skb->data;
207 struct ieee80211_bss *bss;
209 struct ieee80211_channel *channel;
211 struct ieee802_11_elems elems;
214 (!ieee80211_is_probe_resp(mgmt->frame_control) &&
215 !ieee80211_is_beacon(mgmt->frame_control)))
218 sdata1 = rcu_dereference(local->scan_sdata);
219 sdata2 = rcu_dereference(local->sched_scan_sdata);
221 if (likely(!sdata1 && !sdata2))
224 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
225 struct cfg80211_scan_request *scan_req;
226 struct cfg80211_sched_scan_request *sched_scan_req;
227 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
229 scan_req = rcu_dereference(local->scan_req);
230 sched_scan_req = rcu_dereference(local->sched_scan_req);
233 scan_req_flags = scan_req->flags;
236 sched_scan_req_flags = sched_scan_req->flags;
238 /* ignore ProbeResp to foreign address or non-bcast (OCE)
239 * unless scanning with randomised address
241 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
243 !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
247 elements = mgmt->u.probe_resp.variable;
248 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
250 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
251 elements = mgmt->u.beacon.variable;
254 if (baselen > skb->len)
257 ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems);
259 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
261 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
264 bss = ieee80211_bss_info_update(local, rx_status,
265 mgmt, skb->len, &elems,
268 ieee80211_rx_bss_put(local, bss);
272 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
273 enum nl80211_bss_scan_width scan_width)
275 memset(chandef, 0, sizeof(*chandef));
276 switch (scan_width) {
277 case NL80211_BSS_CHAN_WIDTH_5:
278 chandef->width = NL80211_CHAN_WIDTH_5;
280 case NL80211_BSS_CHAN_WIDTH_10:
281 chandef->width = NL80211_CHAN_WIDTH_10;
284 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
289 /* return false if no more work */
290 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
292 struct cfg80211_scan_request *req;
293 struct cfg80211_chan_def chandef;
295 int i, ielen, n_chans;
297 req = rcu_dereference_protected(local->scan_req,
298 lockdep_is_held(&local->mtx));
300 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
303 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
304 for (i = 0; i < req->n_channels; i++) {
305 local->hw_scan_req->req.channels[i] = req->channels[i];
306 bands_used |= BIT(req->channels[i]->band);
309 n_chans = req->n_channels;
312 if (local->hw_scan_band == NUM_NL80211_BANDS)
317 for (i = 0; i < req->n_channels; i++) {
318 if (req->channels[i]->band !=
321 local->hw_scan_req->req.channels[n_chans] =
324 bands_used |= BIT(req->channels[i]->band);
327 local->hw_scan_band++;
331 local->hw_scan_req->req.n_channels = n_chans;
332 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
334 ielen = ieee80211_build_preq_ies(local,
335 (u8 *)local->hw_scan_req->req.ie,
336 local->hw_scan_ies_bufsize,
337 &local->hw_scan_req->ies,
338 req->ie, req->ie_len,
339 bands_used, req->rates, &chandef);
340 local->hw_scan_req->req.ie_len = ielen;
341 local->hw_scan_req->req.no_cck = req->no_cck;
342 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
343 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
345 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
350 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
352 struct ieee80211_local *local = hw_to_local(hw);
353 bool hw_scan = local->ops->hw_scan;
354 bool was_scanning = local->scanning;
355 struct cfg80211_scan_request *scan_req;
356 struct ieee80211_sub_if_data *scan_sdata;
357 struct ieee80211_sub_if_data *sdata;
359 lockdep_assert_held(&local->mtx);
362 * It's ok to abort a not-yet-running scan (that
363 * we have one at all will be verified by checking
364 * local->scan_req next), but not to complete it
367 if (WARN_ON(!local->scanning && !aborted))
370 if (WARN_ON(!local->scan_req))
373 if (hw_scan && !aborted &&
374 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
375 ieee80211_prep_hw_scan(local)) {
378 rc = drv_hw_scan(local,
379 rcu_dereference_protected(local->scan_sdata,
380 lockdep_is_held(&local->mtx)),
386 /* HW scan failed and is going to be reported as aborted,
387 * so clear old scan info.
389 memset(&local->scan_info, 0, sizeof(local->scan_info));
393 kfree(local->hw_scan_req);
394 local->hw_scan_req = NULL;
396 scan_req = rcu_dereference_protected(local->scan_req,
397 lockdep_is_held(&local->mtx));
399 if (scan_req != local->int_scan_req) {
400 local->scan_info.aborted = aborted;
401 cfg80211_scan_done(scan_req, &local->scan_info);
403 RCU_INIT_POINTER(local->scan_req, NULL);
405 scan_sdata = rcu_dereference_protected(local->scan_sdata,
406 lockdep_is_held(&local->mtx));
407 RCU_INIT_POINTER(local->scan_sdata, NULL);
410 local->scan_chandef.chan = NULL;
412 /* Set power back to normal operating levels. */
413 ieee80211_hw_config(local, 0);
416 ieee80211_configure_filter(local);
417 drv_sw_scan_complete(local, scan_sdata);
418 ieee80211_offchannel_return(local);
421 ieee80211_recalc_idle(local);
423 ieee80211_mlme_notify_scan_completed(local);
424 ieee80211_ibss_notify_scan_completed(local);
426 /* Requeue all the work that might have been ignored while
427 * the scan was in progress; if there was none this will
428 * just be a no-op for the particular interface.
430 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
431 if (ieee80211_sdata_running(sdata))
432 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
436 ieee80211_start_next_roc(local);
439 void ieee80211_scan_completed(struct ieee80211_hw *hw,
440 struct cfg80211_scan_info *info)
442 struct ieee80211_local *local = hw_to_local(hw);
444 trace_api_scan_completed(local, info->aborted);
446 set_bit(SCAN_COMPLETED, &local->scanning);
448 set_bit(SCAN_ABORTED, &local->scanning);
450 memcpy(&local->scan_info, info, sizeof(*info));
452 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
454 EXPORT_SYMBOL(ieee80211_scan_completed);
456 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
457 struct ieee80211_sub_if_data *sdata)
459 /* Software scan is not supported in multi-channel cases */
460 if (local->use_chanctx)
464 * Hardware/driver doesn't support hw_scan, so use software
465 * scanning instead. First send a nullfunc frame with power save
466 * bit on so that AP will buffer the frames for us while we are not
467 * listening, then send probe requests to each channel and wait for
468 * the responses. After all channels are scanned, tune back to the
469 * original channel and send a nullfunc frame with power save bit
470 * off to trigger the AP to send us all the buffered frames.
472 * Note that while local->sw_scanning is true everything else but
473 * nullfunc frames and probe requests will be dropped in
474 * ieee80211_tx_h_check_assoc().
476 drv_sw_scan_start(local, sdata, local->scan_addr);
478 local->leave_oper_channel_time = jiffies;
479 local->next_scan_state = SCAN_DECISION;
480 local->scan_channel_idx = 0;
482 ieee80211_offchannel_stop_vifs(local);
484 /* ensure nullfunc is transmitted before leaving operating channel */
485 ieee80211_flush_queues(local, NULL, false);
487 ieee80211_configure_filter(local);
489 /* We need to set power level at maximum rate for scanning. */
490 ieee80211_hw_config(local, 0);
492 ieee80211_queue_delayed_work(&local->hw,
493 &local->scan_work, 0);
498 static bool ieee80211_can_scan(struct ieee80211_local *local,
499 struct ieee80211_sub_if_data *sdata)
501 if (ieee80211_is_radar_required(local))
504 if (!list_empty(&local->roc_list))
507 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
508 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
514 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
516 lockdep_assert_held(&local->mtx);
518 if (!local->scan_req || local->scanning)
521 if (!ieee80211_can_scan(local,
522 rcu_dereference_protected(
524 lockdep_is_held(&local->mtx))))
527 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
528 round_jiffies_relative(0));
531 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
532 unsigned long *next_delay)
535 struct ieee80211_sub_if_data *sdata;
536 struct cfg80211_scan_request *scan_req;
537 enum nl80211_band band = local->hw.conf.chandef.chan->band;
540 scan_req = rcu_dereference_protected(local->scan_req,
541 lockdep_is_held(&local->mtx));
543 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
544 if (scan_req->no_cck)
545 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
547 sdata = rcu_dereference_protected(local->scan_sdata,
548 lockdep_is_held(&local->mtx));
550 for (i = 0; i < scan_req->n_ssids; i++)
551 ieee80211_send_probe_req(
552 sdata, local->scan_addr, scan_req->bssid,
553 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
554 scan_req->ie, scan_req->ie_len,
555 scan_req->rates[band], false,
556 tx_flags, local->hw.conf.chandef.chan, true);
559 * After sending probe requests, wait for probe responses
562 *next_delay = IEEE80211_CHANNEL_TIME;
563 local->next_scan_state = SCAN_DECISION;
566 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
567 struct cfg80211_scan_request *req)
569 struct ieee80211_local *local = sdata->local;
572 lockdep_assert_held(&local->mtx);
574 if (local->scan_req || ieee80211_is_radar_required(local))
577 if (!ieee80211_can_scan(local, sdata)) {
578 /* wait for the work to finish/time out */
579 rcu_assign_pointer(local->scan_req, req);
580 rcu_assign_pointer(local->scan_sdata, sdata);
584 if (local->ops->hw_scan) {
587 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
589 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
591 u8 bands_counted = 0;
593 for (i = 0; i < req->n_channels; i++) {
594 if (bands_counted & BIT(req->channels[i]->band))
596 bands_counted |= BIT(req->channels[i]->band);
600 local->hw_scan_ies_bufsize *= n_bands;
603 local->hw_scan_req = kmalloc(
604 sizeof(*local->hw_scan_req) +
605 req->n_channels * sizeof(req->channels[0]) +
606 local->hw_scan_ies_bufsize, GFP_KERNEL);
607 if (!local->hw_scan_req)
610 local->hw_scan_req->req.ssids = req->ssids;
611 local->hw_scan_req->req.n_ssids = req->n_ssids;
612 ies = (u8 *)local->hw_scan_req +
613 sizeof(*local->hw_scan_req) +
614 req->n_channels * sizeof(req->channels[0]);
615 local->hw_scan_req->req.ie = ies;
616 local->hw_scan_req->req.flags = req->flags;
617 eth_broadcast_addr(local->hw_scan_req->req.bssid);
618 local->hw_scan_req->req.duration = req->duration;
619 local->hw_scan_req->req.duration_mandatory =
620 req->duration_mandatory;
622 local->hw_scan_band = 0;
625 * After allocating local->hw_scan_req, we must
626 * go through until ieee80211_prep_hw_scan(), so
627 * anything that might be changed here and leave
628 * this function early must not go after this
633 rcu_assign_pointer(local->scan_req, req);
634 rcu_assign_pointer(local->scan_sdata, sdata);
636 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
637 get_random_mask_addr(local->scan_addr,
641 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
643 if (local->ops->hw_scan) {
644 __set_bit(SCAN_HW_SCANNING, &local->scanning);
645 } else if ((req->n_channels == 1) &&
646 (req->channels[0] == local->_oper_chandef.chan)) {
648 * If we are scanning only on the operating channel
649 * then we do not need to stop normal activities
651 unsigned long next_delay;
653 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
655 ieee80211_recalc_idle(local);
657 /* Notify driver scan is starting, keep order of operations
658 * same as normal software scan, in case that matters. */
659 drv_sw_scan_start(local, sdata, local->scan_addr);
661 ieee80211_configure_filter(local); /* accept probe-responses */
663 /* We need to ensure power level is at max for scanning. */
664 ieee80211_hw_config(local, 0);
666 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
667 IEEE80211_CHAN_RADAR)) ||
669 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
671 ieee80211_scan_state_send_probe(local, &next_delay);
672 next_delay = IEEE80211_CHANNEL_TIME;
675 /* Now, just wait a bit and we are all done! */
676 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
680 /* Do normal software scan */
681 __set_bit(SCAN_SW_SCANNING, &local->scanning);
684 ieee80211_recalc_idle(local);
686 if (local->ops->hw_scan) {
687 WARN_ON(!ieee80211_prep_hw_scan(local));
688 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
690 rc = ieee80211_start_sw_scan(local, sdata);
694 kfree(local->hw_scan_req);
695 local->hw_scan_req = NULL;
698 ieee80211_recalc_idle(local);
700 local->scan_req = NULL;
701 RCU_INIT_POINTER(local->scan_sdata, NULL);
708 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
711 * TODO: channel switching also consumes quite some time,
712 * add that delay as well to get a better estimation
714 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
715 return IEEE80211_PASSIVE_CHANNEL_TIME;
716 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
719 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
720 unsigned long *next_delay)
722 bool associated = false;
723 bool tx_empty = true;
725 struct ieee80211_sub_if_data *sdata;
726 struct ieee80211_channel *next_chan;
727 enum mac80211_scan_state next_scan_state;
728 struct cfg80211_scan_request *scan_req;
731 * check if at least one STA interface is associated,
732 * check if at least one STA interface has pending tx frames
733 * and grab the lowest used beacon interval
735 mutex_lock(&local->iflist_mtx);
736 list_for_each_entry(sdata, &local->interfaces, list) {
737 if (!ieee80211_sdata_running(sdata))
740 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
741 if (sdata->u.mgd.associated) {
744 if (!qdisc_all_tx_empty(sdata->dev)) {
751 mutex_unlock(&local->iflist_mtx);
753 scan_req = rcu_dereference_protected(local->scan_req,
754 lockdep_is_held(&local->mtx));
756 next_chan = scan_req->channels[local->scan_channel_idx];
759 * we're currently scanning a different channel, let's
760 * see if we can scan another channel without interfering
761 * with the current traffic situation.
763 * Keep good latency, do not stay off-channel more than 125 ms.
766 bad_latency = time_after(jiffies +
767 ieee80211_scan_get_channel_time(next_chan),
768 local->leave_oper_channel_time + HZ / 8);
770 if (associated && !tx_empty) {
771 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
772 next_scan_state = SCAN_ABORT;
774 next_scan_state = SCAN_SUSPEND;
775 } else if (associated && bad_latency) {
776 next_scan_state = SCAN_SUSPEND;
778 next_scan_state = SCAN_SET_CHANNEL;
781 local->next_scan_state = next_scan_state;
786 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
787 unsigned long *next_delay)
790 struct ieee80211_channel *chan;
791 enum nl80211_bss_scan_width oper_scan_width;
792 struct cfg80211_scan_request *scan_req;
794 scan_req = rcu_dereference_protected(local->scan_req,
795 lockdep_is_held(&local->mtx));
798 chan = scan_req->channels[local->scan_channel_idx];
800 local->scan_chandef.chan = chan;
801 local->scan_chandef.center_freq1 = chan->center_freq;
802 local->scan_chandef.center_freq2 = 0;
803 switch (scan_req->scan_width) {
804 case NL80211_BSS_CHAN_WIDTH_5:
805 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
807 case NL80211_BSS_CHAN_WIDTH_10:
808 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
810 case NL80211_BSS_CHAN_WIDTH_20:
811 /* If scanning on oper channel, use whatever channel-type
812 * is currently in use.
814 oper_scan_width = cfg80211_chandef_to_scan_width(
815 &local->_oper_chandef);
816 if (chan == local->_oper_chandef.chan &&
817 oper_scan_width == scan_req->scan_width)
818 local->scan_chandef = local->_oper_chandef;
820 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
824 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
827 /* advance state machine to next channel/band */
828 local->scan_channel_idx++;
831 /* if we skip this channel return to the decision state */
832 local->next_scan_state = SCAN_DECISION;
837 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
838 * (which unfortunately doesn't say _why_ step a) is done,
839 * but it waits for the probe delay or until a frame is
840 * received - and the received frame would update the NAV).
841 * For now, we do not support waiting until a frame is
844 * In any case, it is not necessary for a passive scan.
846 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
847 !scan_req->n_ssids) {
848 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
849 local->next_scan_state = SCAN_DECISION;
853 /* active scan, send probes */
854 *next_delay = IEEE80211_PROBE_DELAY;
855 local->next_scan_state = SCAN_SEND_PROBE;
858 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
859 unsigned long *next_delay)
861 /* switch back to the operating channel */
862 local->scan_chandef.chan = NULL;
863 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
866 ieee80211_offchannel_return(local);
868 *next_delay = HZ / 5;
869 /* afterwards, resume scan & go to next channel */
870 local->next_scan_state = SCAN_RESUME;
873 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
874 unsigned long *next_delay)
876 ieee80211_offchannel_stop_vifs(local);
878 if (local->ops->flush) {
879 ieee80211_flush_queues(local, NULL, false);
882 *next_delay = HZ / 10;
884 /* remember when we left the operating channel */
885 local->leave_oper_channel_time = jiffies;
887 /* advance to the next channel to be scanned */
888 local->next_scan_state = SCAN_SET_CHANNEL;
891 void ieee80211_scan_work(struct work_struct *work)
893 struct ieee80211_local *local =
894 container_of(work, struct ieee80211_local, scan_work.work);
895 struct ieee80211_sub_if_data *sdata;
896 struct cfg80211_scan_request *scan_req;
897 unsigned long next_delay = 0;
900 mutex_lock(&local->mtx);
902 if (!ieee80211_can_run_worker(local)) {
907 sdata = rcu_dereference_protected(local->scan_sdata,
908 lockdep_is_held(&local->mtx));
909 scan_req = rcu_dereference_protected(local->scan_req,
910 lockdep_is_held(&local->mtx));
912 /* When scanning on-channel, the first-callback means completed. */
913 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
914 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
918 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
919 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
923 if (!sdata || !scan_req)
926 if (!local->scanning) {
929 RCU_INIT_POINTER(local->scan_req, NULL);
930 RCU_INIT_POINTER(local->scan_sdata, NULL);
932 rc = __ieee80211_start_scan(sdata, scan_req);
934 /* need to complete scan in cfg80211 */
935 rcu_assign_pointer(local->scan_req, scan_req);
943 * as long as no delay is required advance immediately
944 * without scheduling a new work
947 if (!ieee80211_sdata_running(sdata)) {
952 switch (local->next_scan_state) {
954 /* if no more bands/channels left, complete scan */
955 if (local->scan_channel_idx >= scan_req->n_channels) {
959 ieee80211_scan_state_decision(local, &next_delay);
961 case SCAN_SET_CHANNEL:
962 ieee80211_scan_state_set_channel(local, &next_delay);
964 case SCAN_SEND_PROBE:
965 ieee80211_scan_state_send_probe(local, &next_delay);
968 ieee80211_scan_state_suspend(local, &next_delay);
971 ieee80211_scan_state_resume(local, &next_delay);
977 } while (next_delay == 0);
979 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
983 __ieee80211_scan_completed(&local->hw, aborted);
985 mutex_unlock(&local->mtx);
988 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
989 struct cfg80211_scan_request *req)
993 mutex_lock(&sdata->local->mtx);
994 res = __ieee80211_start_scan(sdata, req);
995 mutex_unlock(&sdata->local->mtx);
1000 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1001 const u8 *ssid, u8 ssid_len,
1002 struct ieee80211_channel **channels,
1003 unsigned int n_channels,
1004 enum nl80211_bss_scan_width scan_width)
1006 struct ieee80211_local *local = sdata->local;
1007 int ret = -EBUSY, i, n_ch = 0;
1008 enum nl80211_band band;
1010 mutex_lock(&local->mtx);
1013 if (local->scan_req)
1016 /* fill internal scan request */
1020 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1021 if (!local->hw.wiphy->bands[band])
1024 max_n = local->hw.wiphy->bands[band]->n_channels;
1025 for (i = 0; i < max_n; i++) {
1026 struct ieee80211_channel *tmp_ch =
1027 &local->hw.wiphy->bands[band]->channels[i];
1029 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1030 IEEE80211_CHAN_DISABLED))
1033 local->int_scan_req->channels[n_ch] = tmp_ch;
1038 if (WARN_ON_ONCE(n_ch == 0))
1041 local->int_scan_req->n_channels = n_ch;
1043 for (i = 0; i < n_channels; i++) {
1044 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1045 IEEE80211_CHAN_DISABLED))
1048 local->int_scan_req->channels[n_ch] = channels[i];
1052 if (WARN_ON_ONCE(n_ch == 0))
1055 local->int_scan_req->n_channels = n_ch;
1058 local->int_scan_req->ssids = &local->scan_ssid;
1059 local->int_scan_req->n_ssids = 1;
1060 local->int_scan_req->scan_width = scan_width;
1061 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1062 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1064 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1066 mutex_unlock(&local->mtx);
1071 * Only call this function when a scan can't be queued -- under RTNL.
1073 void ieee80211_scan_cancel(struct ieee80211_local *local)
1076 * We are canceling software scan, or deferred scan that was not
1077 * yet really started (see __ieee80211_start_scan ).
1079 * Regarding hardware scan:
1080 * - we can not call __ieee80211_scan_completed() as when
1081 * SCAN_HW_SCANNING bit is set this function change
1082 * local->hw_scan_req to operate on 5G band, what race with
1083 * driver which can use local->hw_scan_req
1085 * - we can not cancel scan_work since driver can schedule it
1086 * by ieee80211_scan_completed(..., true) to finish scan
1088 * Hence we only call the cancel_hw_scan() callback, but the low-level
1089 * driver is still responsible for calling ieee80211_scan_completed()
1090 * after the scan was completed/aborted.
1093 mutex_lock(&local->mtx);
1094 if (!local->scan_req)
1098 * We have a scan running and the driver already reported completion,
1099 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1102 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1103 test_bit(SCAN_COMPLETED, &local->scanning)) {
1104 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1108 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1110 * Make sure that __ieee80211_scan_completed doesn't trigger a
1111 * scan on another band.
1113 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1114 if (local->ops->cancel_hw_scan)
1115 drv_cancel_hw_scan(local,
1116 rcu_dereference_protected(local->scan_sdata,
1117 lockdep_is_held(&local->mtx)));
1122 * If the work is currently running, it must be blocked on
1123 * the mutex, but we'll set scan_sdata = NULL and it'll
1124 * simply exit once it acquires the mutex.
1126 cancel_delayed_work(&local->scan_work);
1128 memset(&local->scan_info, 0, sizeof(local->scan_info));
1129 __ieee80211_scan_completed(&local->hw, true);
1131 mutex_unlock(&local->mtx);
1134 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1135 struct cfg80211_sched_scan_request *req)
1137 struct ieee80211_local *local = sdata->local;
1138 struct ieee80211_scan_ies sched_scan_ies = {};
1139 struct cfg80211_chan_def chandef;
1140 int ret, i, iebufsz, num_bands = 0;
1141 u32 rate_masks[NUM_NL80211_BANDS] = {};
1145 iebufsz = local->scan_ies_len + req->ie_len;
1147 lockdep_assert_held(&local->mtx);
1149 if (!local->ops->sched_scan_start)
1152 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1153 if (local->hw.wiphy->bands[i]) {
1154 bands_used |= BIT(i);
1155 rate_masks[i] = (u32) -1;
1160 ie = kzalloc(num_bands * iebufsz, GFP_KERNEL);
1166 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1168 ieee80211_build_preq_ies(local, ie, num_bands * iebufsz,
1169 &sched_scan_ies, req->ie,
1170 req->ie_len, bands_used, rate_masks, &chandef);
1172 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1174 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1175 rcu_assign_pointer(local->sched_scan_req, req);
1182 /* Clean in case of failure after HW restart or upon resume. */
1183 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1184 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1190 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1191 struct cfg80211_sched_scan_request *req)
1193 struct ieee80211_local *local = sdata->local;
1196 mutex_lock(&local->mtx);
1198 if (rcu_access_pointer(local->sched_scan_sdata)) {
1199 mutex_unlock(&local->mtx);
1203 ret = __ieee80211_request_sched_scan_start(sdata, req);
1205 mutex_unlock(&local->mtx);
1209 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1211 struct ieee80211_sub_if_data *sched_scan_sdata;
1214 mutex_lock(&local->mtx);
1216 if (!local->ops->sched_scan_stop) {
1221 /* We don't want to restart sched scan anymore. */
1222 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1224 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1225 lockdep_is_held(&local->mtx));
1226 if (sched_scan_sdata) {
1227 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1229 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1232 mutex_unlock(&local->mtx);
1237 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1239 struct ieee80211_local *local = hw_to_local(hw);
1241 trace_api_sched_scan_results(local);
1243 cfg80211_sched_scan_results(hw->wiphy, 0);
1245 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1247 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1249 mutex_lock(&local->mtx);
1251 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1252 mutex_unlock(&local->mtx);
1256 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1258 /* If sched scan was aborted by the driver. */
1259 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1261 mutex_unlock(&local->mtx);
1263 cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1266 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1268 struct ieee80211_local *local =
1269 container_of(work, struct ieee80211_local,
1270 sched_scan_stopped_work);
1272 ieee80211_sched_scan_end(local);
1275 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1277 struct ieee80211_local *local = hw_to_local(hw);
1279 trace_api_sched_scan_stopped(local);
1282 * this shouldn't really happen, so for simplicity
1283 * simply ignore it, and let mac80211 reconfigure
1284 * the sched scan later on.
1286 if (local->in_reconfig)
1289 schedule_work(&local->sched_scan_stopped_work);
1291 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);