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>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
15 #include <linux/if_arp.h>
16 #include <linux/etherdevice.h>
17 #include <linux/rtnetlink.h>
18 #include <linux/pm_qos.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;
71 if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
72 signal = rx_status->signal * 100;
73 else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC)
74 signal = (rx_status->signal * 100) / local->hw.max_signal;
76 cbss = cfg80211_inform_bss_frame(local->hw.wiphy, channel,
77 mgmt, len, signal, GFP_ATOMIC);
81 bss = (void *)cbss->priv;
84 bss->device_ts_beacon = rx_status->device_timestamp;
86 bss->device_ts_presp = rx_status->device_timestamp;
88 if (elems->parse_error) {
90 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
92 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
95 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
97 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
100 /* save the ERP value so that it is available at association time */
101 if (elems->erp_info && (!elems->parse_error ||
102 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
103 bss->erp_value = elems->erp_info[0];
104 bss->has_erp_value = true;
105 if (!elems->parse_error)
106 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
109 /* replace old supported rates if we get new values */
110 if (!elems->parse_error ||
111 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
113 if (elems->supp_rates) {
114 clen = IEEE80211_MAX_SUPP_RATES;
115 if (clen > elems->supp_rates_len)
116 clen = elems->supp_rates_len;
117 memcpy(bss->supp_rates, elems->supp_rates, clen);
120 if (elems->ext_supp_rates) {
121 clen = IEEE80211_MAX_SUPP_RATES - srlen;
122 if (clen > elems->ext_supp_rates_len)
123 clen = elems->ext_supp_rates_len;
124 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
129 bss->supp_rates_len = srlen;
130 if (!elems->parse_error)
131 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
135 if (!elems->parse_error ||
136 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
137 bss->wmm_used = elems->wmm_param || elems->wmm_info;
138 bss->uapsd_supported = is_uapsd_supported(elems);
139 if (!elems->parse_error)
140 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
146 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
148 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
149 struct ieee80211_sub_if_data *sdata1, *sdata2;
150 struct ieee80211_mgmt *mgmt = (void *)skb->data;
151 struct ieee80211_bss *bss;
153 struct ieee80211_channel *channel;
155 struct ieee802_11_elems elems;
158 (!ieee80211_is_probe_resp(mgmt->frame_control) &&
159 !ieee80211_is_beacon(mgmt->frame_control)))
162 sdata1 = rcu_dereference(local->scan_sdata);
163 sdata2 = rcu_dereference(local->sched_scan_sdata);
165 if (likely(!sdata1 && !sdata2))
168 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
169 /* ignore ProbeResp to foreign address */
170 if ((!sdata1 || !ether_addr_equal(mgmt->da, sdata1->vif.addr)) &&
171 (!sdata2 || !ether_addr_equal(mgmt->da, sdata2->vif.addr)))
174 elements = mgmt->u.probe_resp.variable;
175 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
177 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
178 elements = mgmt->u.beacon.variable;
181 if (baselen > skb->len)
184 ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems);
186 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
188 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
191 bss = ieee80211_bss_info_update(local, rx_status,
192 mgmt, skb->len, &elems,
195 ieee80211_rx_bss_put(local, bss);
198 /* return false if no more work */
199 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
201 struct cfg80211_scan_request *req = local->scan_req;
202 enum ieee80211_band band;
203 int i, ielen, n_chans;
205 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
209 if (local->hw_scan_band == IEEE80211_NUM_BANDS)
212 band = local->hw_scan_band;
214 for (i = 0; i < req->n_channels; i++) {
215 if (req->channels[i]->band == band) {
216 local->hw_scan_req->channels[n_chans] =
222 local->hw_scan_band++;
225 local->hw_scan_req->n_channels = n_chans;
227 ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie,
228 local->hw_scan_ies_bufsize,
229 req->ie, req->ie_len, band,
230 req->rates[band], 0);
231 local->hw_scan_req->ie_len = ielen;
232 local->hw_scan_req->no_cck = req->no_cck;
237 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted,
240 struct ieee80211_local *local = hw_to_local(hw);
242 lockdep_assert_held(&local->mtx);
245 * It's ok to abort a not-yet-running scan (that
246 * we have one at all will be verified by checking
247 * local->scan_req next), but not to complete it
250 if (WARN_ON(!local->scanning && !aborted))
253 if (WARN_ON(!local->scan_req))
256 if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) {
259 rc = drv_hw_scan(local,
260 rcu_dereference_protected(local->scan_sdata,
261 lockdep_is_held(&local->mtx)),
268 kfree(local->hw_scan_req);
269 local->hw_scan_req = NULL;
271 if (local->scan_req != local->int_scan_req)
272 cfg80211_scan_done(local->scan_req, aborted);
273 local->scan_req = NULL;
274 rcu_assign_pointer(local->scan_sdata, NULL);
277 local->scan_channel = NULL;
279 /* Set power back to normal operating levels. */
280 ieee80211_hw_config(local, 0);
283 ieee80211_configure_filter(local);
284 drv_sw_scan_complete(local);
285 ieee80211_offchannel_return(local);
288 ieee80211_recalc_idle(local);
290 ieee80211_mlme_notify_scan_completed(local);
291 ieee80211_ibss_notify_scan_completed(local);
292 ieee80211_mesh_notify_scan_completed(local);
293 ieee80211_start_next_roc(local);
296 void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
298 struct ieee80211_local *local = hw_to_local(hw);
300 trace_api_scan_completed(local, aborted);
302 set_bit(SCAN_COMPLETED, &local->scanning);
304 set_bit(SCAN_ABORTED, &local->scanning);
305 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
307 EXPORT_SYMBOL(ieee80211_scan_completed);
309 static int ieee80211_start_sw_scan(struct ieee80211_local *local)
311 /* Software scan is not supported in multi-channel cases */
312 if (local->use_chanctx)
316 * Hardware/driver doesn't support hw_scan, so use software
317 * scanning instead. First send a nullfunc frame with power save
318 * bit on so that AP will buffer the frames for us while we are not
319 * listening, then send probe requests to each channel and wait for
320 * the responses. After all channels are scanned, tune back to the
321 * original channel and send a nullfunc frame with power save bit
322 * off to trigger the AP to send us all the buffered frames.
324 * Note that while local->sw_scanning is true everything else but
325 * nullfunc frames and probe requests will be dropped in
326 * ieee80211_tx_h_check_assoc().
328 drv_sw_scan_start(local);
330 local->leave_oper_channel_time = jiffies;
331 local->next_scan_state = SCAN_DECISION;
332 local->scan_channel_idx = 0;
334 ieee80211_offchannel_stop_vifs(local);
336 /* ensure nullfunc is transmitted before leaving operating channel */
337 ieee80211_flush_queues(local, NULL);
339 ieee80211_configure_filter(local);
341 /* We need to set power level at maximum rate for scanning. */
342 ieee80211_hw_config(local, 0);
344 ieee80211_queue_delayed_work(&local->hw,
345 &local->scan_work, 0);
350 static bool ieee80211_can_scan(struct ieee80211_local *local,
351 struct ieee80211_sub_if_data *sdata)
353 if (local->radar_detect_enabled)
356 if (!list_empty(&local->roc_list))
359 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
360 sdata->u.mgd.flags & (IEEE80211_STA_BEACON_POLL |
361 IEEE80211_STA_CONNECTION_POLL))
367 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
369 lockdep_assert_held(&local->mtx);
371 if (!local->scan_req || local->scanning)
374 if (!ieee80211_can_scan(local,
375 rcu_dereference_protected(
377 lockdep_is_held(&local->mtx))))
380 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
381 round_jiffies_relative(0));
384 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
385 unsigned long *next_delay)
388 struct ieee80211_sub_if_data *sdata;
389 enum ieee80211_band band = local->hw.conf.chandef.chan->band;
392 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
393 if (local->scan_req->no_cck)
394 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
396 sdata = rcu_dereference_protected(local->scan_sdata,
397 lockdep_is_held(&local->mtx));
399 for (i = 0; i < local->scan_req->n_ssids; i++)
400 ieee80211_send_probe_req(
402 local->scan_req->ssids[i].ssid,
403 local->scan_req->ssids[i].ssid_len,
404 local->scan_req->ie, local->scan_req->ie_len,
405 local->scan_req->rates[band], false,
406 tx_flags, local->hw.conf.chandef.chan, true);
409 * After sending probe requests, wait for probe responses
412 *next_delay = IEEE80211_CHANNEL_TIME;
413 local->next_scan_state = SCAN_DECISION;
416 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
417 struct cfg80211_scan_request *req)
419 struct ieee80211_local *local = sdata->local;
422 lockdep_assert_held(&local->mtx);
427 if (!ieee80211_can_scan(local, sdata)) {
428 /* wait for the work to finish/time out */
429 local->scan_req = req;
430 rcu_assign_pointer(local->scan_sdata, sdata);
434 if (local->ops->hw_scan) {
437 local->hw_scan_ies_bufsize = 2 + IEEE80211_MAX_SSID_LEN +
438 local->scan_ies_len +
440 local->hw_scan_req = kmalloc(
441 sizeof(*local->hw_scan_req) +
442 req->n_channels * sizeof(req->channels[0]) +
443 local->hw_scan_ies_bufsize, GFP_KERNEL);
444 if (!local->hw_scan_req)
447 local->hw_scan_req->ssids = req->ssids;
448 local->hw_scan_req->n_ssids = req->n_ssids;
449 ies = (u8 *)local->hw_scan_req +
450 sizeof(*local->hw_scan_req) +
451 req->n_channels * sizeof(req->channels[0]);
452 local->hw_scan_req->ie = ies;
453 local->hw_scan_req->flags = req->flags;
455 local->hw_scan_band = 0;
458 * After allocating local->hw_scan_req, we must
459 * go through until ieee80211_prep_hw_scan(), so
460 * anything that might be changed here and leave
461 * this function early must not go after this
466 local->scan_req = req;
467 rcu_assign_pointer(local->scan_sdata, sdata);
469 if (local->ops->hw_scan) {
470 __set_bit(SCAN_HW_SCANNING, &local->scanning);
471 } else if ((req->n_channels == 1) &&
472 (req->channels[0] == local->_oper_chandef.chan)) {
474 * If we are scanning only on the operating channel
475 * then we do not need to stop normal activities
477 unsigned long next_delay;
479 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
481 ieee80211_recalc_idle(local);
483 /* Notify driver scan is starting, keep order of operations
484 * same as normal software scan, in case that matters. */
485 drv_sw_scan_start(local);
487 ieee80211_configure_filter(local); /* accept probe-responses */
489 /* We need to ensure power level is at max for scanning. */
490 ieee80211_hw_config(local, 0);
492 if ((req->channels[0]->flags &
493 IEEE80211_CHAN_PASSIVE_SCAN) ||
494 !local->scan_req->n_ssids) {
495 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
497 ieee80211_scan_state_send_probe(local, &next_delay);
498 next_delay = IEEE80211_CHANNEL_TIME;
501 /* Now, just wait a bit and we are all done! */
502 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
506 /* Do normal software scan */
507 __set_bit(SCAN_SW_SCANNING, &local->scanning);
510 ieee80211_recalc_idle(local);
512 if (local->ops->hw_scan) {
513 WARN_ON(!ieee80211_prep_hw_scan(local));
514 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
516 rc = ieee80211_start_sw_scan(local);
519 kfree(local->hw_scan_req);
520 local->hw_scan_req = NULL;
523 ieee80211_recalc_idle(local);
525 local->scan_req = NULL;
526 rcu_assign_pointer(local->scan_sdata, NULL);
533 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
536 * TODO: channel switching also consumes quite some time,
537 * add that delay as well to get a better estimation
539 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN)
540 return IEEE80211_PASSIVE_CHANNEL_TIME;
541 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
544 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
545 unsigned long *next_delay)
547 bool associated = false;
548 bool tx_empty = true;
550 struct ieee80211_sub_if_data *sdata;
551 struct ieee80211_channel *next_chan;
552 enum mac80211_scan_state next_scan_state;
555 * check if at least one STA interface is associated,
556 * check if at least one STA interface has pending tx frames
557 * and grab the lowest used beacon interval
559 mutex_lock(&local->iflist_mtx);
560 list_for_each_entry(sdata, &local->interfaces, list) {
561 if (!ieee80211_sdata_running(sdata))
564 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
565 if (sdata->u.mgd.associated) {
568 if (!qdisc_all_tx_empty(sdata->dev)) {
575 mutex_unlock(&local->iflist_mtx);
577 next_chan = local->scan_req->channels[local->scan_channel_idx];
580 * we're currently scanning a different channel, let's
581 * see if we can scan another channel without interfering
582 * with the current traffic situation.
584 * Keep good latency, do not stay off-channel more than 125 ms.
587 bad_latency = time_after(jiffies +
588 ieee80211_scan_get_channel_time(next_chan),
589 local->leave_oper_channel_time + HZ / 8);
591 if (associated && !tx_empty) {
592 if (local->scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
593 next_scan_state = SCAN_ABORT;
595 next_scan_state = SCAN_SUSPEND;
596 } else if (associated && bad_latency) {
597 next_scan_state = SCAN_SUSPEND;
599 next_scan_state = SCAN_SET_CHANNEL;
602 local->next_scan_state = next_scan_state;
607 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
608 unsigned long *next_delay)
611 struct ieee80211_channel *chan;
614 chan = local->scan_req->channels[local->scan_channel_idx];
616 local->scan_channel = chan;
618 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
621 /* advance state machine to next channel/band */
622 local->scan_channel_idx++;
625 /* if we skip this channel return to the decision state */
626 local->next_scan_state = SCAN_DECISION;
631 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
632 * (which unfortunately doesn't say _why_ step a) is done,
633 * but it waits for the probe delay or until a frame is
634 * received - and the received frame would update the NAV).
635 * For now, we do not support waiting until a frame is
638 * In any case, it is not necessary for a passive scan.
640 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN ||
641 !local->scan_req->n_ssids) {
642 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
643 local->next_scan_state = SCAN_DECISION;
647 /* active scan, send probes */
648 *next_delay = IEEE80211_PROBE_DELAY;
649 local->next_scan_state = SCAN_SEND_PROBE;
652 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
653 unsigned long *next_delay)
655 /* switch back to the operating channel */
656 local->scan_channel = NULL;
657 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
660 ieee80211_offchannel_return(local);
662 *next_delay = HZ / 5;
663 /* afterwards, resume scan & go to next channel */
664 local->next_scan_state = SCAN_RESUME;
667 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
668 unsigned long *next_delay)
670 ieee80211_offchannel_stop_vifs(local);
672 if (local->ops->flush) {
673 ieee80211_flush_queues(local, NULL);
676 *next_delay = HZ / 10;
678 /* remember when we left the operating channel */
679 local->leave_oper_channel_time = jiffies;
681 /* advance to the next channel to be scanned */
682 local->next_scan_state = SCAN_SET_CHANNEL;
685 void ieee80211_scan_work(struct work_struct *work)
687 struct ieee80211_local *local =
688 container_of(work, struct ieee80211_local, scan_work.work);
689 struct ieee80211_sub_if_data *sdata;
690 unsigned long next_delay = 0;
691 bool aborted, hw_scan;
693 mutex_lock(&local->mtx);
695 sdata = rcu_dereference_protected(local->scan_sdata,
696 lockdep_is_held(&local->mtx));
698 /* When scanning on-channel, the first-callback means completed. */
699 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
700 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
704 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
705 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
709 if (!sdata || !local->scan_req)
712 if (local->scan_req && !local->scanning) {
713 struct cfg80211_scan_request *req = local->scan_req;
716 local->scan_req = NULL;
717 rcu_assign_pointer(local->scan_sdata, NULL);
719 rc = __ieee80211_start_scan(sdata, req);
721 /* need to complete scan in cfg80211 */
722 local->scan_req = req;
730 * Avoid re-scheduling when the sdata is going away.
732 if (!ieee80211_sdata_running(sdata)) {
738 * as long as no delay is required advance immediately
739 * without scheduling a new work
742 if (!ieee80211_sdata_running(sdata)) {
747 switch (local->next_scan_state) {
749 /* if no more bands/channels left, complete scan */
750 if (local->scan_channel_idx >= local->scan_req->n_channels) {
754 ieee80211_scan_state_decision(local, &next_delay);
756 case SCAN_SET_CHANNEL:
757 ieee80211_scan_state_set_channel(local, &next_delay);
759 case SCAN_SEND_PROBE:
760 ieee80211_scan_state_send_probe(local, &next_delay);
763 ieee80211_scan_state_suspend(local, &next_delay);
766 ieee80211_scan_state_resume(local, &next_delay);
772 } while (next_delay == 0);
774 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
778 hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
779 __ieee80211_scan_completed(&local->hw, aborted, hw_scan);
781 mutex_unlock(&local->mtx);
784 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
785 struct cfg80211_scan_request *req)
789 mutex_lock(&sdata->local->mtx);
790 res = __ieee80211_start_scan(sdata, req);
791 mutex_unlock(&sdata->local->mtx);
796 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
797 const u8 *ssid, u8 ssid_len,
798 struct ieee80211_channel *chan)
800 struct ieee80211_local *local = sdata->local;
802 enum ieee80211_band band;
804 mutex_lock(&local->mtx);
810 /* fill internal scan request */
815 for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
816 if (!local->hw.wiphy->bands[band])
819 max_n = local->hw.wiphy->bands[band]->n_channels;
820 for (i = 0; i < max_n; i++) {
821 struct ieee80211_channel *tmp_ch =
822 &local->hw.wiphy->bands[band]->channels[i];
824 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IBSS |
825 IEEE80211_CHAN_DISABLED))
828 local->int_scan_req->channels[n_ch] = tmp_ch;
833 if (WARN_ON_ONCE(n_ch == 0))
836 local->int_scan_req->n_channels = n_ch;
838 if (WARN_ON_ONCE(chan->flags & (IEEE80211_CHAN_NO_IBSS |
839 IEEE80211_CHAN_DISABLED)))
842 local->int_scan_req->channels[0] = chan;
843 local->int_scan_req->n_channels = 1;
846 local->int_scan_req->ssids = &local->scan_ssid;
847 local->int_scan_req->n_ssids = 1;
848 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
849 local->int_scan_req->ssids[0].ssid_len = ssid_len;
851 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
853 mutex_unlock(&local->mtx);
858 * Only call this function when a scan can't be queued -- under RTNL.
860 void ieee80211_scan_cancel(struct ieee80211_local *local)
863 * We are canceling software scan, or deferred scan that was not
864 * yet really started (see __ieee80211_start_scan ).
866 * Regarding hardware scan:
867 * - we can not call __ieee80211_scan_completed() as when
868 * SCAN_HW_SCANNING bit is set this function change
869 * local->hw_scan_req to operate on 5G band, what race with
870 * driver which can use local->hw_scan_req
872 * - we can not cancel scan_work since driver can schedule it
873 * by ieee80211_scan_completed(..., true) to finish scan
875 * Hence we only call the cancel_hw_scan() callback, but the low-level
876 * driver is still responsible for calling ieee80211_scan_completed()
877 * after the scan was completed/aborted.
880 mutex_lock(&local->mtx);
881 if (!local->scan_req)
885 * We have a scan running and the driver already reported completion,
886 * but the worker hasn't run yet or is stuck on the mutex - mark it as
889 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
890 test_bit(SCAN_COMPLETED, &local->scanning)) {
891 set_bit(SCAN_HW_CANCELLED, &local->scanning);
895 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
897 * Make sure that __ieee80211_scan_completed doesn't trigger a
898 * scan on another band.
900 set_bit(SCAN_HW_CANCELLED, &local->scanning);
901 if (local->ops->cancel_hw_scan)
902 drv_cancel_hw_scan(local,
903 rcu_dereference_protected(local->scan_sdata,
904 lockdep_is_held(&local->mtx)));
909 * If the work is currently running, it must be blocked on
910 * the mutex, but we'll set scan_sdata = NULL and it'll
911 * simply exit once it acquires the mutex.
913 cancel_delayed_work(&local->scan_work);
915 __ieee80211_scan_completed(&local->hw, true, false);
917 mutex_unlock(&local->mtx);
920 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
921 struct cfg80211_sched_scan_request *req)
923 struct ieee80211_local *local = sdata->local;
924 struct ieee80211_sched_scan_ies sched_scan_ies = {};
927 iebufsz = 2 + IEEE80211_MAX_SSID_LEN +
928 local->scan_ies_len + req->ie_len;
930 mutex_lock(&local->mtx);
932 if (rcu_access_pointer(local->sched_scan_sdata)) {
937 if (!local->ops->sched_scan_start) {
942 for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
943 if (!local->hw.wiphy->bands[i])
946 sched_scan_ies.ie[i] = kzalloc(iebufsz, GFP_KERNEL);
947 if (!sched_scan_ies.ie[i]) {
952 sched_scan_ies.len[i] =
953 ieee80211_build_preq_ies(local, sched_scan_ies.ie[i],
954 iebufsz, req->ie, req->ie_len,
958 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
960 rcu_assign_pointer(local->sched_scan_sdata, sdata);
964 kfree(sched_scan_ies.ie[--i]);
966 mutex_unlock(&local->mtx);
970 int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata)
972 struct ieee80211_local *local = sdata->local;
975 mutex_lock(&local->mtx);
977 if (!local->ops->sched_scan_stop) {
982 if (rcu_access_pointer(local->sched_scan_sdata))
983 drv_sched_scan_stop(local, sdata);
986 mutex_unlock(&local->mtx);
991 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
993 struct ieee80211_local *local = hw_to_local(hw);
995 trace_api_sched_scan_results(local);
997 cfg80211_sched_scan_results(hw->wiphy);
999 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1001 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1003 struct ieee80211_local *local =
1004 container_of(work, struct ieee80211_local,
1005 sched_scan_stopped_work);
1007 mutex_lock(&local->mtx);
1009 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1010 mutex_unlock(&local->mtx);
1014 rcu_assign_pointer(local->sched_scan_sdata, NULL);
1016 mutex_unlock(&local->mtx);
1018 cfg80211_sched_scan_stopped(local->hw.wiphy);
1021 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1023 struct ieee80211_local *local = hw_to_local(hw);
1025 trace_api_sched_scan_stopped(local);
1027 ieee80211_queue_work(&local->hw, &local->sched_scan_stopped_work);
1029 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);