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
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
16 #include <linux/if_arp.h>
17 #include <linux/etherdevice.h>
18 #include <linux/rtnetlink.h>
19 #include <net/sch_generic.h>
20 #include <linux/slab.h>
21 #include <linux/export.h>
22 #include <net/mac80211.h>
24 #include "ieee80211_i.h"
25 #include "driver-ops.h"
28 #define IEEE80211_PROBE_DELAY (HZ / 33)
29 #define IEEE80211_CHANNEL_TIME (HZ / 33)
30 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
32 void ieee80211_rx_bss_put(struct ieee80211_local *local,
33 struct ieee80211_bss *bss)
37 cfg80211_put_bss(local->hw.wiphy,
38 container_of((void *)bss, struct cfg80211_bss, priv));
41 static bool is_uapsd_supported(struct ieee802_11_elems *elems)
45 if (elems->wmm_info && elems->wmm_info_len == 7
46 && elems->wmm_info[5] == 1)
47 qos_info = elems->wmm_info[6];
48 else if (elems->wmm_param && elems->wmm_param_len == 24
49 && elems->wmm_param[5] == 1)
50 qos_info = elems->wmm_param[6];
52 /* no valid wmm information or parameter element found */
55 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
58 struct ieee80211_bss *
59 ieee80211_bss_info_update(struct ieee80211_local *local,
60 struct ieee80211_rx_status *rx_status,
61 struct ieee80211_mgmt *mgmt, size_t len,
62 struct ieee802_11_elems *elems,
63 struct ieee80211_channel *channel)
65 bool beacon = ieee80211_is_beacon(mgmt->frame_control);
66 struct cfg80211_bss *cbss;
67 struct ieee80211_bss *bss;
69 struct cfg80211_inform_bss bss_meta = {
70 .boottime_ns = rx_status->boottime_ns,
74 if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
75 bss_meta.signal = rx_status->signal * 100;
76 else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
77 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
79 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
80 if (rx_status->flag & RX_FLAG_5MHZ)
81 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
82 if (rx_status->flag & RX_FLAG_10MHZ)
83 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
85 bss_meta.chan = channel;
86 cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
87 mgmt, len, GFP_ATOMIC);
90 /* In case the signal is invalid update the status */
91 signal_valid = abs(channel->center_freq - cbss->channel->center_freq)
92 <= local->hw.wiphy->max_adj_channel_rssi_comp;
94 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
96 bss = (void *)cbss->priv;
99 bss->device_ts_beacon = rx_status->device_timestamp;
101 bss->device_ts_presp = rx_status->device_timestamp;
103 if (elems->parse_error) {
105 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
107 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
110 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
112 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
115 /* save the ERP value so that it is available at association time */
116 if (elems->erp_info && (!elems->parse_error ||
117 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
118 bss->erp_value = elems->erp_info[0];
119 bss->has_erp_value = true;
120 if (!elems->parse_error)
121 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
124 /* replace old supported rates if we get new values */
125 if (!elems->parse_error ||
126 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
128 if (elems->supp_rates) {
129 clen = IEEE80211_MAX_SUPP_RATES;
130 if (clen > elems->supp_rates_len)
131 clen = elems->supp_rates_len;
132 memcpy(bss->supp_rates, elems->supp_rates, clen);
135 if (elems->ext_supp_rates) {
136 clen = IEEE80211_MAX_SUPP_RATES - srlen;
137 if (clen > elems->ext_supp_rates_len)
138 clen = elems->ext_supp_rates_len;
139 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
144 bss->supp_rates_len = srlen;
145 if (!elems->parse_error)
146 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
150 if (!elems->parse_error ||
151 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
152 bss->wmm_used = elems->wmm_param || elems->wmm_info;
153 bss->uapsd_supported = is_uapsd_supported(elems);
154 if (!elems->parse_error)
155 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
159 struct ieee80211_supported_band *sband =
160 local->hw.wiphy->bands[rx_status->band];
161 if (!(rx_status->flag & RX_FLAG_HT) &&
162 !(rx_status->flag & RX_FLAG_VHT))
164 &sband->bitrates[rx_status->rate_idx];
170 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
172 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
173 struct ieee80211_sub_if_data *sdata1, *sdata2;
174 struct ieee80211_mgmt *mgmt = (void *)skb->data;
175 struct ieee80211_bss *bss;
177 struct ieee80211_channel *channel;
179 struct ieee802_11_elems elems;
182 (!ieee80211_is_probe_resp(mgmt->frame_control) &&
183 !ieee80211_is_beacon(mgmt->frame_control)))
186 sdata1 = rcu_dereference(local->scan_sdata);
187 sdata2 = rcu_dereference(local->sched_scan_sdata);
189 if (likely(!sdata1 && !sdata2))
192 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
193 struct cfg80211_scan_request *scan_req;
194 struct cfg80211_sched_scan_request *sched_scan_req;
196 scan_req = rcu_dereference(local->scan_req);
197 sched_scan_req = rcu_dereference(local->sched_scan_req);
199 /* ignore ProbeResp to foreign address unless scanning
200 * with randomised address
203 (ether_addr_equal(mgmt->da, sdata1->vif.addr) ||
204 scan_req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)) &&
206 (ether_addr_equal(mgmt->da, sdata2->vif.addr) ||
207 sched_scan_req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)))
210 elements = mgmt->u.probe_resp.variable;
211 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
213 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
214 elements = mgmt->u.beacon.variable;
217 if (baselen > skb->len)
220 ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems);
222 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
224 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
227 bss = ieee80211_bss_info_update(local, rx_status,
228 mgmt, skb->len, &elems,
231 ieee80211_rx_bss_put(local, bss);
235 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
236 enum nl80211_bss_scan_width scan_width)
238 memset(chandef, 0, sizeof(*chandef));
239 switch (scan_width) {
240 case NL80211_BSS_CHAN_WIDTH_5:
241 chandef->width = NL80211_CHAN_WIDTH_5;
243 case NL80211_BSS_CHAN_WIDTH_10:
244 chandef->width = NL80211_CHAN_WIDTH_10;
247 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
252 /* return false if no more work */
253 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
255 struct cfg80211_scan_request *req;
256 struct cfg80211_chan_def chandef;
258 int i, ielen, n_chans;
260 req = rcu_dereference_protected(local->scan_req,
261 lockdep_is_held(&local->mtx));
263 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
266 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
267 for (i = 0; i < req->n_channels; i++) {
268 local->hw_scan_req->req.channels[i] = req->channels[i];
269 bands_used |= BIT(req->channels[i]->band);
272 n_chans = req->n_channels;
275 if (local->hw_scan_band == IEEE80211_NUM_BANDS)
280 for (i = 0; i < req->n_channels; i++) {
281 if (req->channels[i]->band !=
284 local->hw_scan_req->req.channels[n_chans] =
287 bands_used |= BIT(req->channels[i]->band);
290 local->hw_scan_band++;
294 local->hw_scan_req->req.n_channels = n_chans;
295 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
297 ielen = ieee80211_build_preq_ies(local,
298 (u8 *)local->hw_scan_req->req.ie,
299 local->hw_scan_ies_bufsize,
300 &local->hw_scan_req->ies,
301 req->ie, req->ie_len,
302 bands_used, req->rates, &chandef);
303 local->hw_scan_req->req.ie_len = ielen;
304 local->hw_scan_req->req.no_cck = req->no_cck;
305 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
306 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
312 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
314 struct ieee80211_local *local = hw_to_local(hw);
315 bool hw_scan = local->ops->hw_scan;
316 bool was_scanning = local->scanning;
317 struct cfg80211_scan_request *scan_req;
318 struct ieee80211_sub_if_data *scan_sdata;
319 struct ieee80211_sub_if_data *sdata;
321 lockdep_assert_held(&local->mtx);
324 * It's ok to abort a not-yet-running scan (that
325 * we have one at all will be verified by checking
326 * local->scan_req next), but not to complete it
329 if (WARN_ON(!local->scanning && !aborted))
332 if (WARN_ON(!local->scan_req))
335 if (hw_scan && !aborted &&
336 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
337 ieee80211_prep_hw_scan(local)) {
340 rc = drv_hw_scan(local,
341 rcu_dereference_protected(local->scan_sdata,
342 lockdep_is_held(&local->mtx)),
349 kfree(local->hw_scan_req);
350 local->hw_scan_req = NULL;
352 scan_req = rcu_dereference_protected(local->scan_req,
353 lockdep_is_held(&local->mtx));
355 if (scan_req != local->int_scan_req)
356 cfg80211_scan_done(scan_req, aborted);
357 RCU_INIT_POINTER(local->scan_req, NULL);
359 scan_sdata = rcu_dereference_protected(local->scan_sdata,
360 lockdep_is_held(&local->mtx));
361 RCU_INIT_POINTER(local->scan_sdata, NULL);
364 local->scan_chandef.chan = NULL;
366 /* Set power back to normal operating levels. */
367 ieee80211_hw_config(local, 0);
370 ieee80211_configure_filter(local);
371 drv_sw_scan_complete(local, scan_sdata);
372 ieee80211_offchannel_return(local);
375 ieee80211_recalc_idle(local);
377 ieee80211_mlme_notify_scan_completed(local);
378 ieee80211_ibss_notify_scan_completed(local);
380 /* Requeue all the work that might have been ignored while
381 * the scan was in progress; if there was none this will
382 * just be a no-op for the particular interface.
384 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
385 if (ieee80211_sdata_running(sdata))
386 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
390 ieee80211_start_next_roc(local);
393 void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
395 struct ieee80211_local *local = hw_to_local(hw);
397 trace_api_scan_completed(local, aborted);
399 set_bit(SCAN_COMPLETED, &local->scanning);
401 set_bit(SCAN_ABORTED, &local->scanning);
402 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
404 EXPORT_SYMBOL(ieee80211_scan_completed);
406 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
407 struct ieee80211_sub_if_data *sdata)
409 /* Software scan is not supported in multi-channel cases */
410 if (local->use_chanctx)
414 * Hardware/driver doesn't support hw_scan, so use software
415 * scanning instead. First send a nullfunc frame with power save
416 * bit on so that AP will buffer the frames for us while we are not
417 * listening, then send probe requests to each channel and wait for
418 * the responses. After all channels are scanned, tune back to the
419 * original channel and send a nullfunc frame with power save bit
420 * off to trigger the AP to send us all the buffered frames.
422 * Note that while local->sw_scanning is true everything else but
423 * nullfunc frames and probe requests will be dropped in
424 * ieee80211_tx_h_check_assoc().
426 drv_sw_scan_start(local, sdata, local->scan_addr);
428 local->leave_oper_channel_time = jiffies;
429 local->next_scan_state = SCAN_DECISION;
430 local->scan_channel_idx = 0;
432 ieee80211_offchannel_stop_vifs(local);
434 /* ensure nullfunc is transmitted before leaving operating channel */
435 ieee80211_flush_queues(local, NULL, false);
437 ieee80211_configure_filter(local);
439 /* We need to set power level at maximum rate for scanning. */
440 ieee80211_hw_config(local, 0);
442 ieee80211_queue_delayed_work(&local->hw,
443 &local->scan_work, 0);
448 static bool ieee80211_can_scan(struct ieee80211_local *local,
449 struct ieee80211_sub_if_data *sdata)
451 if (ieee80211_is_radar_required(local))
454 if (!list_empty(&local->roc_list))
457 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
458 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
464 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
466 lockdep_assert_held(&local->mtx);
468 if (!local->scan_req || local->scanning)
471 if (!ieee80211_can_scan(local,
472 rcu_dereference_protected(
474 lockdep_is_held(&local->mtx))))
477 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
478 round_jiffies_relative(0));
481 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
482 unsigned long *next_delay)
485 struct ieee80211_sub_if_data *sdata;
486 struct cfg80211_scan_request *scan_req;
487 enum ieee80211_band band = local->hw.conf.chandef.chan->band;
490 scan_req = rcu_dereference_protected(local->scan_req,
491 lockdep_is_held(&local->mtx));
493 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
494 if (scan_req->no_cck)
495 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
497 sdata = rcu_dereference_protected(local->scan_sdata,
498 lockdep_is_held(&local->mtx));
500 for (i = 0; i < scan_req->n_ssids; i++)
501 ieee80211_send_probe_req(
502 sdata, local->scan_addr, NULL,
503 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
504 scan_req->ie, scan_req->ie_len,
505 scan_req->rates[band], false,
506 tx_flags, local->hw.conf.chandef.chan, true);
509 * After sending probe requests, wait for probe responses
512 *next_delay = IEEE80211_CHANNEL_TIME;
513 local->next_scan_state = SCAN_DECISION;
516 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
517 struct cfg80211_scan_request *req)
519 struct ieee80211_local *local = sdata->local;
522 lockdep_assert_held(&local->mtx);
524 if (local->scan_req || ieee80211_is_radar_required(local))
527 if (!ieee80211_can_scan(local, sdata)) {
528 /* wait for the work to finish/time out */
529 rcu_assign_pointer(local->scan_req, req);
530 rcu_assign_pointer(local->scan_sdata, sdata);
534 if (local->ops->hw_scan) {
537 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
539 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
541 u8 bands_counted = 0;
543 for (i = 0; i < req->n_channels; i++) {
544 if (bands_counted & BIT(req->channels[i]->band))
546 bands_counted |= BIT(req->channels[i]->band);
550 local->hw_scan_ies_bufsize *= n_bands;
553 local->hw_scan_req = kmalloc(
554 sizeof(*local->hw_scan_req) +
555 req->n_channels * sizeof(req->channels[0]) +
556 local->hw_scan_ies_bufsize, GFP_KERNEL);
557 if (!local->hw_scan_req)
560 local->hw_scan_req->req.ssids = req->ssids;
561 local->hw_scan_req->req.n_ssids = req->n_ssids;
562 ies = (u8 *)local->hw_scan_req +
563 sizeof(*local->hw_scan_req) +
564 req->n_channels * sizeof(req->channels[0]);
565 local->hw_scan_req->req.ie = ies;
566 local->hw_scan_req->req.flags = req->flags;
568 local->hw_scan_band = 0;
571 * After allocating local->hw_scan_req, we must
572 * go through until ieee80211_prep_hw_scan(), so
573 * anything that might be changed here and leave
574 * this function early must not go after this
579 rcu_assign_pointer(local->scan_req, req);
580 rcu_assign_pointer(local->scan_sdata, sdata);
582 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
583 get_random_mask_addr(local->scan_addr,
587 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
589 if (local->ops->hw_scan) {
590 __set_bit(SCAN_HW_SCANNING, &local->scanning);
591 } else if ((req->n_channels == 1) &&
592 (req->channels[0] == local->_oper_chandef.chan)) {
594 * If we are scanning only on the operating channel
595 * then we do not need to stop normal activities
597 unsigned long next_delay;
599 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
601 ieee80211_recalc_idle(local);
603 /* Notify driver scan is starting, keep order of operations
604 * same as normal software scan, in case that matters. */
605 drv_sw_scan_start(local, sdata, local->scan_addr);
607 ieee80211_configure_filter(local); /* accept probe-responses */
609 /* We need to ensure power level is at max for scanning. */
610 ieee80211_hw_config(local, 0);
612 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
613 IEEE80211_CHAN_RADAR)) ||
615 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
617 ieee80211_scan_state_send_probe(local, &next_delay);
618 next_delay = IEEE80211_CHANNEL_TIME;
621 /* Now, just wait a bit and we are all done! */
622 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
626 /* Do normal software scan */
627 __set_bit(SCAN_SW_SCANNING, &local->scanning);
630 ieee80211_recalc_idle(local);
632 if (local->ops->hw_scan) {
633 WARN_ON(!ieee80211_prep_hw_scan(local));
634 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
636 rc = ieee80211_start_sw_scan(local, sdata);
640 kfree(local->hw_scan_req);
641 local->hw_scan_req = NULL;
644 ieee80211_recalc_idle(local);
646 local->scan_req = NULL;
647 RCU_INIT_POINTER(local->scan_sdata, NULL);
654 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
657 * TODO: channel switching also consumes quite some time,
658 * add that delay as well to get a better estimation
660 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
661 return IEEE80211_PASSIVE_CHANNEL_TIME;
662 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
665 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
666 unsigned long *next_delay)
668 bool associated = false;
669 bool tx_empty = true;
671 struct ieee80211_sub_if_data *sdata;
672 struct ieee80211_channel *next_chan;
673 enum mac80211_scan_state next_scan_state;
674 struct cfg80211_scan_request *scan_req;
677 * check if at least one STA interface is associated,
678 * check if at least one STA interface has pending tx frames
679 * and grab the lowest used beacon interval
681 mutex_lock(&local->iflist_mtx);
682 list_for_each_entry(sdata, &local->interfaces, list) {
683 if (!ieee80211_sdata_running(sdata))
686 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
687 if (sdata->u.mgd.associated) {
690 if (!qdisc_all_tx_empty(sdata->dev)) {
697 mutex_unlock(&local->iflist_mtx);
699 scan_req = rcu_dereference_protected(local->scan_req,
700 lockdep_is_held(&local->mtx));
702 next_chan = scan_req->channels[local->scan_channel_idx];
705 * we're currently scanning a different channel, let's
706 * see if we can scan another channel without interfering
707 * with the current traffic situation.
709 * Keep good latency, do not stay off-channel more than 125 ms.
712 bad_latency = time_after(jiffies +
713 ieee80211_scan_get_channel_time(next_chan),
714 local->leave_oper_channel_time + HZ / 8);
716 if (associated && !tx_empty) {
717 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
718 next_scan_state = SCAN_ABORT;
720 next_scan_state = SCAN_SUSPEND;
721 } else if (associated && bad_latency) {
722 next_scan_state = SCAN_SUSPEND;
724 next_scan_state = SCAN_SET_CHANNEL;
727 local->next_scan_state = next_scan_state;
732 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
733 unsigned long *next_delay)
736 struct ieee80211_channel *chan;
737 enum nl80211_bss_scan_width oper_scan_width;
738 struct cfg80211_scan_request *scan_req;
740 scan_req = rcu_dereference_protected(local->scan_req,
741 lockdep_is_held(&local->mtx));
744 chan = scan_req->channels[local->scan_channel_idx];
746 local->scan_chandef.chan = chan;
747 local->scan_chandef.center_freq1 = chan->center_freq;
748 local->scan_chandef.center_freq2 = 0;
749 switch (scan_req->scan_width) {
750 case NL80211_BSS_CHAN_WIDTH_5:
751 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
753 case NL80211_BSS_CHAN_WIDTH_10:
754 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
756 case NL80211_BSS_CHAN_WIDTH_20:
757 /* If scanning on oper channel, use whatever channel-type
758 * is currently in use.
760 oper_scan_width = cfg80211_chandef_to_scan_width(
761 &local->_oper_chandef);
762 if (chan == local->_oper_chandef.chan &&
763 oper_scan_width == scan_req->scan_width)
764 local->scan_chandef = local->_oper_chandef;
766 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
770 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
773 /* advance state machine to next channel/band */
774 local->scan_channel_idx++;
777 /* if we skip this channel return to the decision state */
778 local->next_scan_state = SCAN_DECISION;
783 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
784 * (which unfortunately doesn't say _why_ step a) is done,
785 * but it waits for the probe delay or until a frame is
786 * received - and the received frame would update the NAV).
787 * For now, we do not support waiting until a frame is
790 * In any case, it is not necessary for a passive scan.
792 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
793 !scan_req->n_ssids) {
794 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
795 local->next_scan_state = SCAN_DECISION;
799 /* active scan, send probes */
800 *next_delay = IEEE80211_PROBE_DELAY;
801 local->next_scan_state = SCAN_SEND_PROBE;
804 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
805 unsigned long *next_delay)
807 /* switch back to the operating channel */
808 local->scan_chandef.chan = NULL;
809 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
812 ieee80211_offchannel_return(local);
814 *next_delay = HZ / 5;
815 /* afterwards, resume scan & go to next channel */
816 local->next_scan_state = SCAN_RESUME;
819 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
820 unsigned long *next_delay)
822 ieee80211_offchannel_stop_vifs(local);
824 if (local->ops->flush) {
825 ieee80211_flush_queues(local, NULL, false);
828 *next_delay = HZ / 10;
830 /* remember when we left the operating channel */
831 local->leave_oper_channel_time = jiffies;
833 /* advance to the next channel to be scanned */
834 local->next_scan_state = SCAN_SET_CHANNEL;
837 void ieee80211_scan_work(struct work_struct *work)
839 struct ieee80211_local *local =
840 container_of(work, struct ieee80211_local, scan_work.work);
841 struct ieee80211_sub_if_data *sdata;
842 struct cfg80211_scan_request *scan_req;
843 unsigned long next_delay = 0;
846 mutex_lock(&local->mtx);
848 if (!ieee80211_can_run_worker(local)) {
853 sdata = rcu_dereference_protected(local->scan_sdata,
854 lockdep_is_held(&local->mtx));
855 scan_req = rcu_dereference_protected(local->scan_req,
856 lockdep_is_held(&local->mtx));
858 /* When scanning on-channel, the first-callback means completed. */
859 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
860 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
864 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
865 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
869 if (!sdata || !scan_req)
872 if (!local->scanning) {
875 RCU_INIT_POINTER(local->scan_req, NULL);
876 RCU_INIT_POINTER(local->scan_sdata, NULL);
878 rc = __ieee80211_start_scan(sdata, scan_req);
880 /* need to complete scan in cfg80211 */
881 rcu_assign_pointer(local->scan_req, scan_req);
889 * as long as no delay is required advance immediately
890 * without scheduling a new work
893 if (!ieee80211_sdata_running(sdata)) {
898 switch (local->next_scan_state) {
900 /* if no more bands/channels left, complete scan */
901 if (local->scan_channel_idx >= scan_req->n_channels) {
905 ieee80211_scan_state_decision(local, &next_delay);
907 case SCAN_SET_CHANNEL:
908 ieee80211_scan_state_set_channel(local, &next_delay);
910 case SCAN_SEND_PROBE:
911 ieee80211_scan_state_send_probe(local, &next_delay);
914 ieee80211_scan_state_suspend(local, &next_delay);
917 ieee80211_scan_state_resume(local, &next_delay);
923 } while (next_delay == 0);
925 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
929 __ieee80211_scan_completed(&local->hw, aborted);
931 mutex_unlock(&local->mtx);
934 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
935 struct cfg80211_scan_request *req)
939 mutex_lock(&sdata->local->mtx);
940 res = __ieee80211_start_scan(sdata, req);
941 mutex_unlock(&sdata->local->mtx);
946 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
947 const u8 *ssid, u8 ssid_len,
948 struct ieee80211_channel **channels,
949 unsigned int n_channels,
950 enum nl80211_bss_scan_width scan_width)
952 struct ieee80211_local *local = sdata->local;
953 int ret = -EBUSY, i, n_ch = 0;
954 enum ieee80211_band band;
956 mutex_lock(&local->mtx);
962 /* fill internal scan request */
966 for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
967 if (!local->hw.wiphy->bands[band])
970 max_n = local->hw.wiphy->bands[band]->n_channels;
971 for (i = 0; i < max_n; i++) {
972 struct ieee80211_channel *tmp_ch =
973 &local->hw.wiphy->bands[band]->channels[i];
975 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
976 IEEE80211_CHAN_DISABLED))
979 local->int_scan_req->channels[n_ch] = tmp_ch;
984 if (WARN_ON_ONCE(n_ch == 0))
987 local->int_scan_req->n_channels = n_ch;
989 for (i = 0; i < n_channels; i++) {
990 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
991 IEEE80211_CHAN_DISABLED))
994 local->int_scan_req->channels[n_ch] = channels[i];
998 if (WARN_ON_ONCE(n_ch == 0))
1001 local->int_scan_req->n_channels = n_ch;
1004 local->int_scan_req->ssids = &local->scan_ssid;
1005 local->int_scan_req->n_ssids = 1;
1006 local->int_scan_req->scan_width = scan_width;
1007 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1008 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1010 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1012 mutex_unlock(&local->mtx);
1017 * Only call this function when a scan can't be queued -- under RTNL.
1019 void ieee80211_scan_cancel(struct ieee80211_local *local)
1022 * We are canceling software scan, or deferred scan that was not
1023 * yet really started (see __ieee80211_start_scan ).
1025 * Regarding hardware scan:
1026 * - we can not call __ieee80211_scan_completed() as when
1027 * SCAN_HW_SCANNING bit is set this function change
1028 * local->hw_scan_req to operate on 5G band, what race with
1029 * driver which can use local->hw_scan_req
1031 * - we can not cancel scan_work since driver can schedule it
1032 * by ieee80211_scan_completed(..., true) to finish scan
1034 * Hence we only call the cancel_hw_scan() callback, but the low-level
1035 * driver is still responsible for calling ieee80211_scan_completed()
1036 * after the scan was completed/aborted.
1039 mutex_lock(&local->mtx);
1040 if (!local->scan_req)
1044 * We have a scan running and the driver already reported completion,
1045 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1048 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1049 test_bit(SCAN_COMPLETED, &local->scanning)) {
1050 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1054 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1056 * Make sure that __ieee80211_scan_completed doesn't trigger a
1057 * scan on another band.
1059 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1060 if (local->ops->cancel_hw_scan)
1061 drv_cancel_hw_scan(local,
1062 rcu_dereference_protected(local->scan_sdata,
1063 lockdep_is_held(&local->mtx)));
1068 * If the work is currently running, it must be blocked on
1069 * the mutex, but we'll set scan_sdata = NULL and it'll
1070 * simply exit once it acquires the mutex.
1072 cancel_delayed_work(&local->scan_work);
1074 __ieee80211_scan_completed(&local->hw, true);
1076 mutex_unlock(&local->mtx);
1079 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1080 struct cfg80211_sched_scan_request *req)
1082 struct ieee80211_local *local = sdata->local;
1083 struct ieee80211_scan_ies sched_scan_ies = {};
1084 struct cfg80211_chan_def chandef;
1085 int ret, i, iebufsz, num_bands = 0;
1086 u32 rate_masks[IEEE80211_NUM_BANDS] = {};
1091 iebufsz = local->scan_ies_len + req->ie_len;
1093 lockdep_assert_held(&local->mtx);
1095 if (!local->ops->sched_scan_start)
1098 for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
1099 if (local->hw.wiphy->bands[i]) {
1100 bands_used |= BIT(i);
1101 rate_masks[i] = (u32) -1;
1106 ie = kzalloc(num_bands * iebufsz, GFP_KERNEL);
1112 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1114 len = ieee80211_build_preq_ies(local, ie, num_bands * iebufsz,
1115 &sched_scan_ies, req->ie,
1116 req->ie_len, bands_used,
1117 rate_masks, &chandef);
1119 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1121 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1122 rcu_assign_pointer(local->sched_scan_req, req);
1129 /* Clean in case of failure after HW restart or upon resume. */
1130 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1131 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1137 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1138 struct cfg80211_sched_scan_request *req)
1140 struct ieee80211_local *local = sdata->local;
1143 mutex_lock(&local->mtx);
1145 if (rcu_access_pointer(local->sched_scan_sdata)) {
1146 mutex_unlock(&local->mtx);
1150 ret = __ieee80211_request_sched_scan_start(sdata, req);
1152 mutex_unlock(&local->mtx);
1156 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1158 struct ieee80211_sub_if_data *sched_scan_sdata;
1161 mutex_lock(&local->mtx);
1163 if (!local->ops->sched_scan_stop) {
1168 /* We don't want to restart sched scan anymore. */
1169 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1171 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1172 lockdep_is_held(&local->mtx));
1173 if (sched_scan_sdata) {
1174 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1176 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1179 mutex_unlock(&local->mtx);
1184 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1186 struct ieee80211_local *local = hw_to_local(hw);
1188 trace_api_sched_scan_results(local);
1190 cfg80211_sched_scan_results(hw->wiphy);
1192 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1194 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1196 mutex_lock(&local->mtx);
1198 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1199 mutex_unlock(&local->mtx);
1203 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1205 /* If sched scan was aborted by the driver. */
1206 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1208 mutex_unlock(&local->mtx);
1210 cfg80211_sched_scan_stopped(local->hw.wiphy);
1213 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1215 struct ieee80211_local *local =
1216 container_of(work, struct ieee80211_local,
1217 sched_scan_stopped_work);
1219 ieee80211_sched_scan_end(local);
1222 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1224 struct ieee80211_local *local = hw_to_local(hw);
1226 trace_api_sched_scan_stopped(local);
1229 * this shouldn't really happen, so for simplicity
1230 * simply ignore it, and let mac80211 reconfigure
1231 * the sched scan later on.
1233 if (local->in_reconfig)
1236 schedule_work(&local->sched_scan_stopped_work);
1238 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);