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 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 (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
77 bss_meta.signal = rx_status->signal * 100;
78 else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
79 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
81 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
82 if (rx_status->flag & RX_FLAG_5MHZ)
83 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
84 if (rx_status->flag & RX_FLAG_10MHZ)
85 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
87 bss_meta.chan = channel;
90 scan_sdata = rcu_dereference(local->scan_sdata);
91 if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
92 scan_sdata->vif.bss_conf.assoc &&
93 ieee80211_have_rx_timestamp(rx_status)) {
95 ieee80211_calculate_rx_timestamp(local, rx_status,
97 ether_addr_copy(bss_meta.parent_bssid,
98 scan_sdata->vif.bss_conf.bssid);
102 cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
103 mgmt, len, GFP_ATOMIC);
106 /* In case the signal is invalid update the status */
107 signal_valid = abs(channel->center_freq - cbss->channel->center_freq)
108 <= local->hw.wiphy->max_adj_channel_rssi_comp;
110 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
112 bss = (void *)cbss->priv;
115 bss->device_ts_beacon = rx_status->device_timestamp;
117 bss->device_ts_presp = rx_status->device_timestamp;
119 if (elems->parse_error) {
121 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
123 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
126 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
128 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
131 /* save the ERP value so that it is available at association time */
132 if (elems->erp_info && (!elems->parse_error ||
133 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
134 bss->erp_value = elems->erp_info[0];
135 bss->has_erp_value = true;
136 if (!elems->parse_error)
137 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
140 /* replace old supported rates if we get new values */
141 if (!elems->parse_error ||
142 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
144 if (elems->supp_rates) {
145 clen = IEEE80211_MAX_SUPP_RATES;
146 if (clen > elems->supp_rates_len)
147 clen = elems->supp_rates_len;
148 memcpy(bss->supp_rates, elems->supp_rates, clen);
151 if (elems->ext_supp_rates) {
152 clen = IEEE80211_MAX_SUPP_RATES - srlen;
153 if (clen > elems->ext_supp_rates_len)
154 clen = elems->ext_supp_rates_len;
155 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
160 bss->supp_rates_len = srlen;
161 if (!elems->parse_error)
162 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
166 if (!elems->parse_error ||
167 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
168 bss->wmm_used = elems->wmm_param || elems->wmm_info;
169 bss->uapsd_supported = is_uapsd_supported(elems);
170 if (!elems->parse_error)
171 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
175 struct ieee80211_supported_band *sband =
176 local->hw.wiphy->bands[rx_status->band];
177 if (!(rx_status->flag & RX_FLAG_HT) &&
178 !(rx_status->flag & RX_FLAG_VHT))
180 &sband->bitrates[rx_status->rate_idx];
186 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
188 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
189 struct ieee80211_sub_if_data *sdata1, *sdata2;
190 struct ieee80211_mgmt *mgmt = (void *)skb->data;
191 struct ieee80211_bss *bss;
193 struct ieee80211_channel *channel;
195 struct ieee802_11_elems elems;
198 (!ieee80211_is_probe_resp(mgmt->frame_control) &&
199 !ieee80211_is_beacon(mgmt->frame_control)))
202 sdata1 = rcu_dereference(local->scan_sdata);
203 sdata2 = rcu_dereference(local->sched_scan_sdata);
205 if (likely(!sdata1 && !sdata2))
208 if (test_and_clear_bit(SCAN_BEACON_WAIT, &local->scanning)) {
210 * we were passive scanning because of radar/no-IR, but
211 * the beacon/proberesp rx gives us an opportunity to upgrade
214 set_bit(SCAN_BEACON_DONE, &local->scanning);
215 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
218 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
219 struct cfg80211_scan_request *scan_req;
220 struct cfg80211_sched_scan_request *sched_scan_req;
222 scan_req = rcu_dereference(local->scan_req);
223 sched_scan_req = rcu_dereference(local->sched_scan_req);
225 /* ignore ProbeResp to foreign address unless scanning
226 * with randomised address
229 (ether_addr_equal(mgmt->da, sdata1->vif.addr) ||
230 scan_req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)) &&
232 (ether_addr_equal(mgmt->da, sdata2->vif.addr) ||
233 sched_scan_req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)))
236 elements = mgmt->u.probe_resp.variable;
237 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
239 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
240 elements = mgmt->u.beacon.variable;
243 if (baselen > skb->len)
246 ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems);
248 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
250 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
253 bss = ieee80211_bss_info_update(local, rx_status,
254 mgmt, skb->len, &elems,
257 ieee80211_rx_bss_put(local, bss);
261 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
262 enum nl80211_bss_scan_width scan_width)
264 memset(chandef, 0, sizeof(*chandef));
265 switch (scan_width) {
266 case NL80211_BSS_CHAN_WIDTH_5:
267 chandef->width = NL80211_CHAN_WIDTH_5;
269 case NL80211_BSS_CHAN_WIDTH_10:
270 chandef->width = NL80211_CHAN_WIDTH_10;
273 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
278 /* return false if no more work */
279 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
281 struct cfg80211_scan_request *req;
282 struct cfg80211_chan_def chandef;
284 int i, ielen, n_chans;
286 req = rcu_dereference_protected(local->scan_req,
287 lockdep_is_held(&local->mtx));
289 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
292 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
293 for (i = 0; i < req->n_channels; i++) {
294 local->hw_scan_req->req.channels[i] = req->channels[i];
295 bands_used |= BIT(req->channels[i]->band);
298 n_chans = req->n_channels;
301 if (local->hw_scan_band == NUM_NL80211_BANDS)
306 for (i = 0; i < req->n_channels; i++) {
307 if (req->channels[i]->band !=
310 local->hw_scan_req->req.channels[n_chans] =
313 bands_used |= BIT(req->channels[i]->band);
316 local->hw_scan_band++;
320 local->hw_scan_req->req.n_channels = n_chans;
321 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
323 ielen = ieee80211_build_preq_ies(local,
324 (u8 *)local->hw_scan_req->req.ie,
325 local->hw_scan_ies_bufsize,
326 &local->hw_scan_req->ies,
327 req->ie, req->ie_len,
328 bands_used, req->rates, &chandef);
329 local->hw_scan_req->req.ie_len = ielen;
330 local->hw_scan_req->req.no_cck = req->no_cck;
331 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
332 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
334 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
339 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
341 struct ieee80211_local *local = hw_to_local(hw);
342 bool hw_scan = local->ops->hw_scan;
343 bool was_scanning = local->scanning;
344 struct cfg80211_scan_request *scan_req;
345 struct ieee80211_sub_if_data *scan_sdata;
346 struct ieee80211_sub_if_data *sdata;
348 lockdep_assert_held(&local->mtx);
351 * It's ok to abort a not-yet-running scan (that
352 * we have one at all will be verified by checking
353 * local->scan_req next), but not to complete it
356 if (WARN_ON(!local->scanning && !aborted))
359 if (WARN_ON(!local->scan_req))
362 if (hw_scan && !aborted &&
363 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
364 ieee80211_prep_hw_scan(local)) {
367 rc = drv_hw_scan(local,
368 rcu_dereference_protected(local->scan_sdata,
369 lockdep_is_held(&local->mtx)),
375 /* HW scan failed and is going to be reported as aborted,
376 * so clear old scan info.
378 memset(&local->scan_info, 0, sizeof(local->scan_info));
382 kfree(local->hw_scan_req);
383 local->hw_scan_req = NULL;
385 scan_req = rcu_dereference_protected(local->scan_req,
386 lockdep_is_held(&local->mtx));
388 if (scan_req != local->int_scan_req) {
389 local->scan_info.aborted = aborted;
390 cfg80211_scan_done(scan_req, &local->scan_info);
392 RCU_INIT_POINTER(local->scan_req, NULL);
394 scan_sdata = rcu_dereference_protected(local->scan_sdata,
395 lockdep_is_held(&local->mtx));
396 RCU_INIT_POINTER(local->scan_sdata, NULL);
399 local->scan_chandef.chan = NULL;
401 /* Set power back to normal operating levels. */
402 ieee80211_hw_config(local, 0);
405 ieee80211_configure_filter(local);
406 drv_sw_scan_complete(local, scan_sdata);
407 ieee80211_offchannel_return(local);
410 ieee80211_recalc_idle(local);
412 ieee80211_mlme_notify_scan_completed(local);
413 ieee80211_ibss_notify_scan_completed(local);
415 /* Requeue all the work that might have been ignored while
416 * the scan was in progress; if there was none this will
417 * just be a no-op for the particular interface.
419 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
420 if (ieee80211_sdata_running(sdata))
421 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
425 ieee80211_start_next_roc(local);
428 void ieee80211_scan_completed(struct ieee80211_hw *hw,
429 struct cfg80211_scan_info *info)
431 struct ieee80211_local *local = hw_to_local(hw);
433 trace_api_scan_completed(local, info->aborted);
435 set_bit(SCAN_COMPLETED, &local->scanning);
437 set_bit(SCAN_ABORTED, &local->scanning);
439 memcpy(&local->scan_info, info, sizeof(*info));
441 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
443 EXPORT_SYMBOL(ieee80211_scan_completed);
445 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
446 struct ieee80211_sub_if_data *sdata)
448 /* Software scan is not supported in multi-channel cases */
449 if (local->use_chanctx)
453 * Hardware/driver doesn't support hw_scan, so use software
454 * scanning instead. First send a nullfunc frame with power save
455 * bit on so that AP will buffer the frames for us while we are not
456 * listening, then send probe requests to each channel and wait for
457 * the responses. After all channels are scanned, tune back to the
458 * original channel and send a nullfunc frame with power save bit
459 * off to trigger the AP to send us all the buffered frames.
461 * Note that while local->sw_scanning is true everything else but
462 * nullfunc frames and probe requests will be dropped in
463 * ieee80211_tx_h_check_assoc().
465 drv_sw_scan_start(local, sdata, local->scan_addr);
467 local->leave_oper_channel_time = jiffies;
468 local->next_scan_state = SCAN_DECISION;
469 local->scan_channel_idx = 0;
471 ieee80211_offchannel_stop_vifs(local);
473 /* ensure nullfunc is transmitted before leaving operating channel */
474 ieee80211_flush_queues(local, NULL, false);
476 ieee80211_configure_filter(local);
478 /* We need to set power level at maximum rate for scanning. */
479 ieee80211_hw_config(local, 0);
481 ieee80211_queue_delayed_work(&local->hw,
482 &local->scan_work, 0);
487 static bool ieee80211_can_scan(struct ieee80211_local *local,
488 struct ieee80211_sub_if_data *sdata)
490 if (ieee80211_is_radar_required(local))
493 if (!list_empty(&local->roc_list))
496 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
497 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
503 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
505 lockdep_assert_held(&local->mtx);
507 if (!local->scan_req || local->scanning)
510 if (!ieee80211_can_scan(local,
511 rcu_dereference_protected(
513 lockdep_is_held(&local->mtx))))
516 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
517 round_jiffies_relative(0));
520 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
521 unsigned long *next_delay)
524 struct ieee80211_sub_if_data *sdata;
525 struct cfg80211_scan_request *scan_req;
526 enum nl80211_band band = local->hw.conf.chandef.chan->band;
529 scan_req = rcu_dereference_protected(local->scan_req,
530 lockdep_is_held(&local->mtx));
532 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
533 if (scan_req->no_cck)
534 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
536 sdata = rcu_dereference_protected(local->scan_sdata,
537 lockdep_is_held(&local->mtx));
539 for (i = 0; i < scan_req->n_ssids; i++)
540 ieee80211_send_probe_req(
541 sdata, local->scan_addr, scan_req->bssid,
542 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
543 scan_req->ie, scan_req->ie_len,
544 scan_req->rates[band], false,
545 tx_flags, local->hw.conf.chandef.chan, true);
548 * After sending probe requests, wait for probe responses
551 *next_delay = IEEE80211_CHANNEL_TIME;
552 local->next_scan_state = SCAN_DECISION;
555 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
556 struct cfg80211_scan_request *req)
558 struct ieee80211_local *local = sdata->local;
561 lockdep_assert_held(&local->mtx);
563 if (local->scan_req || ieee80211_is_radar_required(local))
566 if (!ieee80211_can_scan(local, sdata)) {
567 /* wait for the work to finish/time out */
568 rcu_assign_pointer(local->scan_req, req);
569 rcu_assign_pointer(local->scan_sdata, sdata);
573 if (local->ops->hw_scan) {
576 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
578 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
580 u8 bands_counted = 0;
582 for (i = 0; i < req->n_channels; i++) {
583 if (bands_counted & BIT(req->channels[i]->band))
585 bands_counted |= BIT(req->channels[i]->band);
589 local->hw_scan_ies_bufsize *= n_bands;
592 local->hw_scan_req = kmalloc(
593 sizeof(*local->hw_scan_req) +
594 req->n_channels * sizeof(req->channels[0]) +
595 local->hw_scan_ies_bufsize, GFP_KERNEL);
596 if (!local->hw_scan_req)
599 local->hw_scan_req->req.ssids = req->ssids;
600 local->hw_scan_req->req.n_ssids = req->n_ssids;
601 ies = (u8 *)local->hw_scan_req +
602 sizeof(*local->hw_scan_req) +
603 req->n_channels * sizeof(req->channels[0]);
604 local->hw_scan_req->req.ie = ies;
605 local->hw_scan_req->req.flags = req->flags;
606 eth_broadcast_addr(local->hw_scan_req->req.bssid);
607 local->hw_scan_req->req.duration = req->duration;
608 local->hw_scan_req->req.duration_mandatory =
609 req->duration_mandatory;
611 local->hw_scan_band = 0;
614 * After allocating local->hw_scan_req, we must
615 * go through until ieee80211_prep_hw_scan(), so
616 * anything that might be changed here and leave
617 * this function early must not go after this
622 rcu_assign_pointer(local->scan_req, req);
623 rcu_assign_pointer(local->scan_sdata, sdata);
625 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
626 get_random_mask_addr(local->scan_addr,
630 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
632 if (local->ops->hw_scan) {
633 __set_bit(SCAN_HW_SCANNING, &local->scanning);
634 } else if ((req->n_channels == 1) &&
635 (req->channels[0] == local->_oper_chandef.chan)) {
637 * If we are scanning only on the operating channel
638 * then we do not need to stop normal activities
640 unsigned long next_delay;
642 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
644 ieee80211_recalc_idle(local);
646 /* Notify driver scan is starting, keep order of operations
647 * same as normal software scan, in case that matters. */
648 drv_sw_scan_start(local, sdata, local->scan_addr);
650 ieee80211_configure_filter(local); /* accept probe-responses */
652 /* We need to ensure power level is at max for scanning. */
653 ieee80211_hw_config(local, 0);
655 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
656 IEEE80211_CHAN_RADAR)) ||
658 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
660 set_bit(SCAN_BEACON_WAIT, &local->scanning);
662 ieee80211_scan_state_send_probe(local, &next_delay);
663 next_delay = IEEE80211_CHANNEL_TIME;
666 /* Now, just wait a bit and we are all done! */
667 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
671 /* Do normal software scan */
672 __set_bit(SCAN_SW_SCANNING, &local->scanning);
675 ieee80211_recalc_idle(local);
677 if (local->ops->hw_scan) {
678 WARN_ON(!ieee80211_prep_hw_scan(local));
679 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
681 rc = ieee80211_start_sw_scan(local, sdata);
685 kfree(local->hw_scan_req);
686 local->hw_scan_req = NULL;
689 ieee80211_recalc_idle(local);
691 local->scan_req = NULL;
692 RCU_INIT_POINTER(local->scan_sdata, NULL);
699 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
702 * TODO: channel switching also consumes quite some time,
703 * add that delay as well to get a better estimation
705 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
706 return IEEE80211_PASSIVE_CHANNEL_TIME;
707 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
710 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
711 unsigned long *next_delay)
713 bool associated = false;
714 bool tx_empty = true;
716 struct ieee80211_sub_if_data *sdata;
717 struct ieee80211_channel *next_chan;
718 enum mac80211_scan_state next_scan_state;
719 struct cfg80211_scan_request *scan_req;
722 * check if at least one STA interface is associated,
723 * check if at least one STA interface has pending tx frames
724 * and grab the lowest used beacon interval
726 mutex_lock(&local->iflist_mtx);
727 list_for_each_entry(sdata, &local->interfaces, list) {
728 if (!ieee80211_sdata_running(sdata))
731 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
732 if (sdata->u.mgd.associated) {
735 if (!qdisc_all_tx_empty(sdata->dev)) {
742 mutex_unlock(&local->iflist_mtx);
744 scan_req = rcu_dereference_protected(local->scan_req,
745 lockdep_is_held(&local->mtx));
747 next_chan = scan_req->channels[local->scan_channel_idx];
750 * we're currently scanning a different channel, let's
751 * see if we can scan another channel without interfering
752 * with the current traffic situation.
754 * Keep good latency, do not stay off-channel more than 125 ms.
757 bad_latency = time_after(jiffies +
758 ieee80211_scan_get_channel_time(next_chan),
759 local->leave_oper_channel_time + HZ / 8);
761 if (associated && !tx_empty) {
762 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
763 next_scan_state = SCAN_ABORT;
765 next_scan_state = SCAN_SUSPEND;
766 } else if (associated && bad_latency) {
767 next_scan_state = SCAN_SUSPEND;
769 next_scan_state = SCAN_SET_CHANNEL;
772 local->next_scan_state = next_scan_state;
777 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
778 unsigned long *next_delay)
781 struct ieee80211_channel *chan;
782 enum nl80211_bss_scan_width oper_scan_width;
783 struct cfg80211_scan_request *scan_req;
785 scan_req = rcu_dereference_protected(local->scan_req,
786 lockdep_is_held(&local->mtx));
789 chan = scan_req->channels[local->scan_channel_idx];
791 local->scan_chandef.chan = chan;
792 local->scan_chandef.center_freq1 = chan->center_freq;
793 local->scan_chandef.center_freq2 = 0;
794 switch (scan_req->scan_width) {
795 case NL80211_BSS_CHAN_WIDTH_5:
796 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
798 case NL80211_BSS_CHAN_WIDTH_10:
799 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
801 case NL80211_BSS_CHAN_WIDTH_20:
802 /* If scanning on oper channel, use whatever channel-type
803 * is currently in use.
805 oper_scan_width = cfg80211_chandef_to_scan_width(
806 &local->_oper_chandef);
807 if (chan == local->_oper_chandef.chan &&
808 oper_scan_width == scan_req->scan_width)
809 local->scan_chandef = local->_oper_chandef;
811 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
815 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
818 /* advance state machine to next channel/band */
819 local->scan_channel_idx++;
822 /* if we skip this channel return to the decision state */
823 local->next_scan_state = SCAN_DECISION;
828 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
829 * (which unfortunately doesn't say _why_ step a) is done,
830 * but it waits for the probe delay or until a frame is
831 * received - and the received frame would update the NAV).
832 * For now, we do not support waiting until a frame is
835 * In any case, it is not necessary for a passive scan.
837 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
838 !scan_req->n_ssids) {
839 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
840 local->next_scan_state = SCAN_DECISION;
841 if (scan_req->n_ssids)
842 set_bit(SCAN_BEACON_WAIT, &local->scanning);
846 /* active scan, send probes */
847 *next_delay = IEEE80211_PROBE_DELAY;
848 local->next_scan_state = SCAN_SEND_PROBE;
851 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
852 unsigned long *next_delay)
854 /* switch back to the operating channel */
855 local->scan_chandef.chan = NULL;
856 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
859 ieee80211_offchannel_return(local);
861 *next_delay = HZ / 5;
862 /* afterwards, resume scan & go to next channel */
863 local->next_scan_state = SCAN_RESUME;
866 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
867 unsigned long *next_delay)
869 ieee80211_offchannel_stop_vifs(local);
871 if (local->ops->flush) {
872 ieee80211_flush_queues(local, NULL, false);
875 *next_delay = HZ / 10;
877 /* remember when we left the operating channel */
878 local->leave_oper_channel_time = jiffies;
880 /* advance to the next channel to be scanned */
881 local->next_scan_state = SCAN_SET_CHANNEL;
884 void ieee80211_scan_work(struct work_struct *work)
886 struct ieee80211_local *local =
887 container_of(work, struct ieee80211_local, scan_work.work);
888 struct ieee80211_sub_if_data *sdata;
889 struct cfg80211_scan_request *scan_req;
890 unsigned long next_delay = 0;
893 mutex_lock(&local->mtx);
895 if (!ieee80211_can_run_worker(local)) {
900 sdata = rcu_dereference_protected(local->scan_sdata,
901 lockdep_is_held(&local->mtx));
902 scan_req = rcu_dereference_protected(local->scan_req,
903 lockdep_is_held(&local->mtx));
905 /* When scanning on-channel, the first-callback means completed. */
906 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
907 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
911 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
912 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
916 if (!sdata || !scan_req)
919 if (!local->scanning) {
922 RCU_INIT_POINTER(local->scan_req, NULL);
923 RCU_INIT_POINTER(local->scan_sdata, NULL);
925 rc = __ieee80211_start_scan(sdata, scan_req);
927 /* need to complete scan in cfg80211 */
928 rcu_assign_pointer(local->scan_req, scan_req);
935 clear_bit(SCAN_BEACON_WAIT, &local->scanning);
938 * as long as no delay is required advance immediately
939 * without scheduling a new work
942 if (!ieee80211_sdata_running(sdata)) {
947 if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) &&
948 local->next_scan_state == SCAN_DECISION)
949 local->next_scan_state = SCAN_SEND_PROBE;
951 switch (local->next_scan_state) {
953 /* if no more bands/channels left, complete scan */
954 if (local->scan_channel_idx >= scan_req->n_channels) {
958 ieee80211_scan_state_decision(local, &next_delay);
960 case SCAN_SET_CHANNEL:
961 ieee80211_scan_state_set_channel(local, &next_delay);
963 case SCAN_SEND_PROBE:
964 ieee80211_scan_state_send_probe(local, &next_delay);
967 ieee80211_scan_state_suspend(local, &next_delay);
970 ieee80211_scan_state_resume(local, &next_delay);
976 } while (next_delay == 0);
978 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
982 __ieee80211_scan_completed(&local->hw, aborted);
984 mutex_unlock(&local->mtx);
987 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
988 struct cfg80211_scan_request *req)
992 mutex_lock(&sdata->local->mtx);
993 res = __ieee80211_start_scan(sdata, req);
994 mutex_unlock(&sdata->local->mtx);
999 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1000 const u8 *ssid, u8 ssid_len,
1001 struct ieee80211_channel **channels,
1002 unsigned int n_channels,
1003 enum nl80211_bss_scan_width scan_width)
1005 struct ieee80211_local *local = sdata->local;
1006 int ret = -EBUSY, i, n_ch = 0;
1007 enum nl80211_band band;
1009 mutex_lock(&local->mtx);
1012 if (local->scan_req)
1015 /* fill internal scan request */
1019 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1020 if (!local->hw.wiphy->bands[band])
1023 max_n = local->hw.wiphy->bands[band]->n_channels;
1024 for (i = 0; i < max_n; i++) {
1025 struct ieee80211_channel *tmp_ch =
1026 &local->hw.wiphy->bands[band]->channels[i];
1028 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1029 IEEE80211_CHAN_DISABLED))
1032 local->int_scan_req->channels[n_ch] = tmp_ch;
1037 if (WARN_ON_ONCE(n_ch == 0))
1040 local->int_scan_req->n_channels = n_ch;
1042 for (i = 0; i < n_channels; i++) {
1043 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1044 IEEE80211_CHAN_DISABLED))
1047 local->int_scan_req->channels[n_ch] = channels[i];
1051 if (WARN_ON_ONCE(n_ch == 0))
1054 local->int_scan_req->n_channels = n_ch;
1057 local->int_scan_req->ssids = &local->scan_ssid;
1058 local->int_scan_req->n_ssids = 1;
1059 local->int_scan_req->scan_width = scan_width;
1060 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1061 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1063 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1065 mutex_unlock(&local->mtx);
1070 * Only call this function when a scan can't be queued -- under RTNL.
1072 void ieee80211_scan_cancel(struct ieee80211_local *local)
1075 * We are canceling software scan, or deferred scan that was not
1076 * yet really started (see __ieee80211_start_scan ).
1078 * Regarding hardware scan:
1079 * - we can not call __ieee80211_scan_completed() as when
1080 * SCAN_HW_SCANNING bit is set this function change
1081 * local->hw_scan_req to operate on 5G band, what race with
1082 * driver which can use local->hw_scan_req
1084 * - we can not cancel scan_work since driver can schedule it
1085 * by ieee80211_scan_completed(..., true) to finish scan
1087 * Hence we only call the cancel_hw_scan() callback, but the low-level
1088 * driver is still responsible for calling ieee80211_scan_completed()
1089 * after the scan was completed/aborted.
1092 mutex_lock(&local->mtx);
1093 if (!local->scan_req)
1097 * We have a scan running and the driver already reported completion,
1098 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1101 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1102 test_bit(SCAN_COMPLETED, &local->scanning)) {
1103 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1107 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1109 * Make sure that __ieee80211_scan_completed doesn't trigger a
1110 * scan on another band.
1112 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1113 if (local->ops->cancel_hw_scan)
1114 drv_cancel_hw_scan(local,
1115 rcu_dereference_protected(local->scan_sdata,
1116 lockdep_is_held(&local->mtx)));
1121 * If the work is currently running, it must be blocked on
1122 * the mutex, but we'll set scan_sdata = NULL and it'll
1123 * simply exit once it acquires the mutex.
1125 cancel_delayed_work(&local->scan_work);
1127 memset(&local->scan_info, 0, sizeof(local->scan_info));
1128 __ieee80211_scan_completed(&local->hw, true);
1130 mutex_unlock(&local->mtx);
1133 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1134 struct cfg80211_sched_scan_request *req)
1136 struct ieee80211_local *local = sdata->local;
1137 struct ieee80211_scan_ies sched_scan_ies = {};
1138 struct cfg80211_chan_def chandef;
1139 int ret, i, iebufsz, num_bands = 0;
1140 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 len = ieee80211_build_preq_ies(local, ie, num_bands * iebufsz,
1169 &sched_scan_ies, req->ie,
1170 req->ie_len, bands_used,
1171 rate_masks, &chandef);
1173 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1175 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1176 rcu_assign_pointer(local->sched_scan_req, req);
1183 /* Clean in case of failure after HW restart or upon resume. */
1184 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1185 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1191 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1192 struct cfg80211_sched_scan_request *req)
1194 struct ieee80211_local *local = sdata->local;
1197 mutex_lock(&local->mtx);
1199 if (rcu_access_pointer(local->sched_scan_sdata)) {
1200 mutex_unlock(&local->mtx);
1204 ret = __ieee80211_request_sched_scan_start(sdata, req);
1206 mutex_unlock(&local->mtx);
1210 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1212 struct ieee80211_sub_if_data *sched_scan_sdata;
1215 mutex_lock(&local->mtx);
1217 if (!local->ops->sched_scan_stop) {
1222 /* We don't want to restart sched scan anymore. */
1223 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1225 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1226 lockdep_is_held(&local->mtx));
1227 if (sched_scan_sdata) {
1228 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1230 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1233 mutex_unlock(&local->mtx);
1238 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1240 struct ieee80211_local *local = hw_to_local(hw);
1242 trace_api_sched_scan_results(local);
1244 cfg80211_sched_scan_results(hw->wiphy);
1246 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1248 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1250 mutex_lock(&local->mtx);
1252 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1253 mutex_unlock(&local->mtx);
1257 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1259 /* If sched scan was aborted by the driver. */
1260 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1262 mutex_unlock(&local->mtx);
1264 cfg80211_sched_scan_stopped(local->hw.wiphy);
1267 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1269 struct ieee80211_local *local =
1270 container_of(work, struct ieee80211_local,
1271 sched_scan_stopped_work);
1273 ieee80211_sched_scan_end(local);
1276 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1278 struct ieee80211_local *local = hw_to_local(hw);
1280 trace_api_sched_scan_stopped(local);
1283 * this shouldn't really happen, so for simplicity
1284 * simply ignore it, and let mac80211 reconfigure
1285 * the sched scan later on.
1287 if (local->in_reconfig)
1290 schedule_work(&local->sched_scan_stopped_work);
1292 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);