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 / 8)
32 static void ieee80211_rx_bss_free(struct cfg80211_bss *cbss)
34 struct ieee80211_bss *bss = (void *)cbss->priv;
36 kfree(bss_mesh_id(bss));
37 kfree(bss_mesh_cfg(bss));
40 void ieee80211_rx_bss_put(struct ieee80211_local *local,
41 struct ieee80211_bss *bss)
45 cfg80211_put_bss(container_of((void *)bss, struct cfg80211_bss, priv));
48 static bool is_uapsd_supported(struct ieee802_11_elems *elems)
52 if (elems->wmm_info && elems->wmm_info_len == 7
53 && elems->wmm_info[5] == 1)
54 qos_info = elems->wmm_info[6];
55 else if (elems->wmm_param && elems->wmm_param_len == 24
56 && elems->wmm_param[5] == 1)
57 qos_info = elems->wmm_param[6];
59 /* no valid wmm information or parameter element found */
62 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
65 struct ieee80211_bss *
66 ieee80211_bss_info_update(struct ieee80211_local *local,
67 struct ieee80211_rx_status *rx_status,
68 struct ieee80211_mgmt *mgmt,
70 struct ieee802_11_elems *elems,
71 struct ieee80211_channel *channel,
74 struct cfg80211_bss *cbss;
75 struct ieee80211_bss *bss;
79 if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
80 signal = rx_status->signal * 100;
81 else if (local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC)
82 signal = (rx_status->signal * 100) / local->hw.max_signal;
84 cbss = cfg80211_inform_bss_frame(local->hw.wiphy, channel,
85 mgmt, len, signal, GFP_ATOMIC);
89 cbss->free_priv = ieee80211_rx_bss_free;
90 bss = (void *)cbss->priv;
92 bss->device_ts = rx_status->device_timestamp;
94 if (elems->parse_error) {
96 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
98 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
101 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
103 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
106 /* save the ERP value so that it is available at association time */
107 if (elems->erp_info && elems->erp_info_len >= 1 &&
108 (!elems->parse_error ||
109 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
110 bss->erp_value = elems->erp_info[0];
111 bss->has_erp_value = true;
112 if (!elems->parse_error)
113 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
116 /* replace old supported rates if we get new values */
117 if (!elems->parse_error ||
118 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
120 if (elems->supp_rates) {
121 clen = IEEE80211_MAX_SUPP_RATES;
122 if (clen > elems->supp_rates_len)
123 clen = elems->supp_rates_len;
124 memcpy(bss->supp_rates, elems->supp_rates, clen);
127 if (elems->ext_supp_rates) {
128 clen = IEEE80211_MAX_SUPP_RATES - srlen;
129 if (clen > elems->ext_supp_rates_len)
130 clen = elems->ext_supp_rates_len;
131 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
136 bss->supp_rates_len = srlen;
137 if (!elems->parse_error)
138 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
142 if (!elems->parse_error ||
143 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
144 bss->wmm_used = elems->wmm_param || elems->wmm_info;
145 bss->uapsd_supported = is_uapsd_supported(elems);
146 if (!elems->parse_error)
147 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
151 bss->last_probe_resp = jiffies;
156 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
158 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
159 struct ieee80211_sub_if_data *sdata1, *sdata2;
160 struct ieee80211_mgmt *mgmt = (void *)skb->data;
161 struct ieee80211_bss *bss;
163 struct ieee80211_channel *channel;
166 struct ieee802_11_elems elems;
169 (!ieee80211_is_probe_resp(mgmt->frame_control) &&
170 !ieee80211_is_beacon(mgmt->frame_control)))
173 sdata1 = rcu_dereference(local->scan_sdata);
174 sdata2 = rcu_dereference(local->sched_scan_sdata);
176 if (likely(!sdata1 && !sdata2))
179 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
180 /* ignore ProbeResp to foreign address */
181 if ((!sdata1 || !ether_addr_equal(mgmt->da, sdata1->vif.addr)) &&
182 (!sdata2 || !ether_addr_equal(mgmt->da, sdata2->vif.addr)))
185 elements = mgmt->u.probe_resp.variable;
186 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
189 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
190 elements = mgmt->u.beacon.variable;
194 if (baselen > skb->len)
197 ieee802_11_parse_elems(elements, skb->len - baselen, &elems);
199 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
201 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
204 bss = ieee80211_bss_info_update(local, rx_status,
205 mgmt, skb->len, &elems,
208 ieee80211_rx_bss_put(local, bss);
211 /* return false if no more work */
212 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
214 struct cfg80211_scan_request *req = local->scan_req;
215 enum ieee80211_band band;
216 int i, ielen, n_chans;
219 if (local->hw_scan_band == IEEE80211_NUM_BANDS)
222 band = local->hw_scan_band;
224 for (i = 0; i < req->n_channels; i++) {
225 if (req->channels[i]->band == band) {
226 local->hw_scan_req->channels[n_chans] =
232 local->hw_scan_band++;
235 local->hw_scan_req->n_channels = n_chans;
237 ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie,
238 local->hw_scan_ies_bufsize,
239 req->ie, req->ie_len, band,
240 req->rates[band], 0);
241 local->hw_scan_req->ie_len = ielen;
242 local->hw_scan_req->no_cck = req->no_cck;
247 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted,
250 struct ieee80211_local *local = hw_to_local(hw);
252 lockdep_assert_held(&local->mtx);
255 * It's ok to abort a not-yet-running scan (that
256 * we have one at all will be verified by checking
257 * local->scan_req next), but not to complete it
260 if (WARN_ON(!local->scanning && !aborted))
263 if (WARN_ON(!local->scan_req))
266 if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) {
269 rc = drv_hw_scan(local,
270 rcu_dereference_protected(local->scan_sdata,
271 lockdep_is_held(&local->mtx)),
278 kfree(local->hw_scan_req);
279 local->hw_scan_req = NULL;
281 if (local->scan_req != local->int_scan_req)
282 cfg80211_scan_done(local->scan_req, aborted);
283 local->scan_req = NULL;
284 rcu_assign_pointer(local->scan_sdata, NULL);
287 local->scan_channel = NULL;
289 /* Set power back to normal operating levels. */
290 ieee80211_hw_config(local, 0);
293 ieee80211_configure_filter(local);
294 drv_sw_scan_complete(local);
295 ieee80211_offchannel_return(local, true);
298 ieee80211_recalc_idle(local);
300 ieee80211_mlme_notify_scan_completed(local);
301 ieee80211_ibss_notify_scan_completed(local);
302 ieee80211_mesh_notify_scan_completed(local);
303 ieee80211_start_next_roc(local);
306 void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
308 struct ieee80211_local *local = hw_to_local(hw);
310 trace_api_scan_completed(local, aborted);
312 set_bit(SCAN_COMPLETED, &local->scanning);
314 set_bit(SCAN_ABORTED, &local->scanning);
315 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
317 EXPORT_SYMBOL(ieee80211_scan_completed);
319 static int ieee80211_start_sw_scan(struct ieee80211_local *local)
321 /* Software scan is not supported in multi-channel cases */
322 if (local->use_chanctx)
326 * Hardware/driver doesn't support hw_scan, so use software
327 * scanning instead. First send a nullfunc frame with power save
328 * bit on so that AP will buffer the frames for us while we are not
329 * listening, then send probe requests to each channel and wait for
330 * the responses. After all channels are scanned, tune back to the
331 * original channel and send a nullfunc frame with power save bit
332 * off to trigger the AP to send us all the buffered frames.
334 * Note that while local->sw_scanning is true everything else but
335 * nullfunc frames and probe requests will be dropped in
336 * ieee80211_tx_h_check_assoc().
338 drv_sw_scan_start(local);
340 local->leave_oper_channel_time = jiffies;
341 local->next_scan_state = SCAN_DECISION;
342 local->scan_channel_idx = 0;
344 ieee80211_offchannel_stop_vifs(local, true);
346 ieee80211_configure_filter(local);
348 /* We need to set power level at maximum rate for scanning. */
349 ieee80211_hw_config(local, 0);
351 ieee80211_queue_delayed_work(&local->hw,
352 &local->scan_work, 0);
357 static bool ieee80211_can_scan(struct ieee80211_local *local,
358 struct ieee80211_sub_if_data *sdata)
360 if (!list_empty(&local->roc_list))
363 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
364 sdata->u.mgd.flags & (IEEE80211_STA_BEACON_POLL |
365 IEEE80211_STA_CONNECTION_POLL))
371 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
373 lockdep_assert_held(&local->mtx);
375 if (!local->scan_req || local->scanning)
378 if (!ieee80211_can_scan(local,
379 rcu_dereference_protected(
381 lockdep_is_held(&local->mtx))))
384 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
385 round_jiffies_relative(0));
388 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
389 unsigned long *next_delay)
392 struct ieee80211_sub_if_data *sdata;
393 enum ieee80211_band band = local->hw.conf.channel->band;
395 sdata = rcu_dereference_protected(local->scan_sdata,
396 lockdep_is_held(&local->mtx));
398 for (i = 0; i < local->scan_req->n_ssids; i++)
399 ieee80211_send_probe_req(
401 local->scan_req->ssids[i].ssid,
402 local->scan_req->ssids[i].ssid_len,
403 local->scan_req->ie, local->scan_req->ie_len,
404 local->scan_req->rates[band], false,
405 local->scan_req->no_cck,
406 local->hw.conf.channel, 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_channel)) {
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 bool listen_int_exceeded;
551 unsigned long min_beacon_int = 0;
552 struct ieee80211_sub_if_data *sdata;
553 struct ieee80211_channel *next_chan;
554 enum mac80211_scan_state next_scan_state;
557 * check if at least one STA interface is associated,
558 * check if at least one STA interface has pending tx frames
559 * and grab the lowest used beacon interval
561 mutex_lock(&local->iflist_mtx);
562 list_for_each_entry(sdata, &local->interfaces, list) {
563 if (!ieee80211_sdata_running(sdata))
566 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
567 if (sdata->u.mgd.associated) {
570 if (sdata->vif.bss_conf.beacon_int <
571 min_beacon_int || min_beacon_int == 0)
573 sdata->vif.bss_conf.beacon_int;
575 if (!qdisc_all_tx_empty(sdata->dev)) {
582 mutex_unlock(&local->iflist_mtx);
584 next_chan = local->scan_req->channels[local->scan_channel_idx];
587 * we're currently scanning a different channel, let's
588 * see if we can scan another channel without interfering
589 * with the current traffic situation.
591 * Since we don't know if the AP has pending frames for us
592 * we can only check for our tx queues and use the current
593 * pm_qos requirements for rx. Hence, if no tx traffic occurs
594 * at all we will scan as many channels in a row as the pm_qos
595 * latency allows us to. Additionally we also check for the
596 * currently negotiated listen interval to prevent losing
597 * frames unnecessarily.
599 * Otherwise switch back to the operating channel.
602 bad_latency = time_after(jiffies +
603 ieee80211_scan_get_channel_time(next_chan),
604 local->leave_oper_channel_time +
605 usecs_to_jiffies(pm_qos_request(PM_QOS_NETWORK_LATENCY)));
607 listen_int_exceeded = time_after(jiffies +
608 ieee80211_scan_get_channel_time(next_chan),
609 local->leave_oper_channel_time +
610 usecs_to_jiffies(min_beacon_int * 1024) *
611 local->hw.conf.listen_interval);
613 if (associated && !tx_empty) {
614 if (local->scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
615 next_scan_state = SCAN_ABORT;
617 next_scan_state = SCAN_SUSPEND;
618 } else if (associated && (bad_latency || listen_int_exceeded)) {
619 next_scan_state = SCAN_SUSPEND;
621 next_scan_state = SCAN_SET_CHANNEL;
624 local->next_scan_state = next_scan_state;
629 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
630 unsigned long *next_delay)
633 struct ieee80211_channel *chan;
636 chan = local->scan_req->channels[local->scan_channel_idx];
638 local->scan_channel = chan;
640 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
643 /* advance state machine to next channel/band */
644 local->scan_channel_idx++;
647 /* if we skip this channel return to the decision state */
648 local->next_scan_state = SCAN_DECISION;
653 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
654 * (which unfortunately doesn't say _why_ step a) is done,
655 * but it waits for the probe delay or until a frame is
656 * received - and the received frame would update the NAV).
657 * For now, we do not support waiting until a frame is
660 * In any case, it is not necessary for a passive scan.
662 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN ||
663 !local->scan_req->n_ssids) {
664 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
665 local->next_scan_state = SCAN_DECISION;
669 /* active scan, send probes */
670 *next_delay = IEEE80211_PROBE_DELAY;
671 local->next_scan_state = SCAN_SEND_PROBE;
674 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
675 unsigned long *next_delay)
677 /* switch back to the operating channel */
678 local->scan_channel = NULL;
679 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
682 * Re-enable vifs and beaconing. Leave PS
683 * in off-channel state..will put that back
684 * on-channel at the end of scanning.
686 ieee80211_offchannel_return(local, false);
688 *next_delay = HZ / 5;
689 /* afterwards, resume scan & go to next channel */
690 local->next_scan_state = SCAN_RESUME;
693 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
694 unsigned long *next_delay)
696 /* PS already is in off-channel mode */
697 ieee80211_offchannel_stop_vifs(local, false);
699 if (local->ops->flush) {
700 drv_flush(local, false);
703 *next_delay = HZ / 10;
705 /* remember when we left the operating channel */
706 local->leave_oper_channel_time = jiffies;
708 /* advance to the next channel to be scanned */
709 local->next_scan_state = SCAN_SET_CHANNEL;
712 void ieee80211_scan_work(struct work_struct *work)
714 struct ieee80211_local *local =
715 container_of(work, struct ieee80211_local, scan_work.work);
716 struct ieee80211_sub_if_data *sdata;
717 unsigned long next_delay = 0;
718 bool aborted, hw_scan;
720 mutex_lock(&local->mtx);
722 sdata = rcu_dereference_protected(local->scan_sdata,
723 lockdep_is_held(&local->mtx));
725 /* When scanning on-channel, the first-callback means completed. */
726 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
727 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
731 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
732 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
736 if (!sdata || !local->scan_req)
739 if (local->scan_req && !local->scanning) {
740 struct cfg80211_scan_request *req = local->scan_req;
743 local->scan_req = NULL;
744 rcu_assign_pointer(local->scan_sdata, NULL);
746 rc = __ieee80211_start_scan(sdata, req);
748 /* need to complete scan in cfg80211 */
749 local->scan_req = req;
757 * Avoid re-scheduling when the sdata is going away.
759 if (!ieee80211_sdata_running(sdata)) {
765 * as long as no delay is required advance immediately
766 * without scheduling a new work
769 if (!ieee80211_sdata_running(sdata)) {
774 switch (local->next_scan_state) {
776 /* if no more bands/channels left, complete scan */
777 if (local->scan_channel_idx >= local->scan_req->n_channels) {
781 ieee80211_scan_state_decision(local, &next_delay);
783 case SCAN_SET_CHANNEL:
784 ieee80211_scan_state_set_channel(local, &next_delay);
786 case SCAN_SEND_PROBE:
787 ieee80211_scan_state_send_probe(local, &next_delay);
790 ieee80211_scan_state_suspend(local, &next_delay);
793 ieee80211_scan_state_resume(local, &next_delay);
799 } while (next_delay == 0);
801 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
805 hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
806 __ieee80211_scan_completed(&local->hw, aborted, hw_scan);
808 mutex_unlock(&local->mtx);
811 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
812 struct cfg80211_scan_request *req)
816 mutex_lock(&sdata->local->mtx);
817 res = __ieee80211_start_scan(sdata, req);
818 mutex_unlock(&sdata->local->mtx);
823 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
824 const u8 *ssid, u8 ssid_len,
825 struct ieee80211_channel *chan)
827 struct ieee80211_local *local = sdata->local;
829 enum ieee80211_band band;
831 mutex_lock(&local->mtx);
837 /* fill internal scan request */
842 for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
843 if (!local->hw.wiphy->bands[band])
846 max_n = local->hw.wiphy->bands[band]->n_channels;
847 for (i = 0; i < max_n; i++) {
848 struct ieee80211_channel *tmp_ch =
849 &local->hw.wiphy->bands[band]->channels[i];
851 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IBSS |
852 IEEE80211_CHAN_DISABLED))
855 local->int_scan_req->channels[n_ch] = tmp_ch;
860 if (WARN_ON_ONCE(n_ch == 0))
863 local->int_scan_req->n_channels = n_ch;
865 if (WARN_ON_ONCE(chan->flags & (IEEE80211_CHAN_NO_IBSS |
866 IEEE80211_CHAN_DISABLED)))
869 local->int_scan_req->channels[0] = chan;
870 local->int_scan_req->n_channels = 1;
873 local->int_scan_req->ssids = &local->scan_ssid;
874 local->int_scan_req->n_ssids = 1;
875 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
876 local->int_scan_req->ssids[0].ssid_len = ssid_len;
878 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
880 mutex_unlock(&local->mtx);
885 * Only call this function when a scan can't be queued -- under RTNL.
887 void ieee80211_scan_cancel(struct ieee80211_local *local)
890 * We are canceling software scan, or deferred scan that was not
891 * yet really started (see __ieee80211_start_scan ).
893 * Regarding hardware scan:
894 * - we can not call __ieee80211_scan_completed() as when
895 * SCAN_HW_SCANNING bit is set this function change
896 * local->hw_scan_req to operate on 5G band, what race with
897 * driver which can use local->hw_scan_req
899 * - we can not cancel scan_work since driver can schedule it
900 * by ieee80211_scan_completed(..., true) to finish scan
902 * Hence we only call the cancel_hw_scan() callback, but the low-level
903 * driver is still responsible for calling ieee80211_scan_completed()
904 * after the scan was completed/aborted.
907 mutex_lock(&local->mtx);
908 if (!local->scan_req)
911 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
912 if (local->ops->cancel_hw_scan)
913 drv_cancel_hw_scan(local,
914 rcu_dereference_protected(local->scan_sdata,
915 lockdep_is_held(&local->mtx)));
920 * If the work is currently running, it must be blocked on
921 * the mutex, but we'll set scan_sdata = NULL and it'll
922 * simply exit once it acquires the mutex.
924 cancel_delayed_work(&local->scan_work);
926 __ieee80211_scan_completed(&local->hw, true, false);
928 mutex_unlock(&local->mtx);
931 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
932 struct cfg80211_sched_scan_request *req)
934 struct ieee80211_local *local = sdata->local;
935 struct ieee80211_sched_scan_ies sched_scan_ies = {};
938 iebufsz = 2 + IEEE80211_MAX_SSID_LEN +
939 local->scan_ies_len + req->ie_len;
941 mutex_lock(&local->mtx);
943 if (rcu_access_pointer(local->sched_scan_sdata)) {
948 if (!local->ops->sched_scan_start) {
953 for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
954 if (!local->hw.wiphy->bands[i])
957 sched_scan_ies.ie[i] = kzalloc(iebufsz, GFP_KERNEL);
958 if (!sched_scan_ies.ie[i]) {
963 sched_scan_ies.len[i] =
964 ieee80211_build_preq_ies(local, sched_scan_ies.ie[i],
965 iebufsz, req->ie, req->ie_len,
969 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
971 rcu_assign_pointer(local->sched_scan_sdata, sdata);
975 kfree(sched_scan_ies.ie[--i]);
977 mutex_unlock(&local->mtx);
981 int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata)
983 struct ieee80211_local *local = sdata->local;
986 mutex_lock(&local->mtx);
988 if (!local->ops->sched_scan_stop) {
993 if (rcu_access_pointer(local->sched_scan_sdata))
994 drv_sched_scan_stop(local, sdata);
997 mutex_unlock(&local->mtx);
1002 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1004 struct ieee80211_local *local = hw_to_local(hw);
1006 trace_api_sched_scan_results(local);
1008 cfg80211_sched_scan_results(hw->wiphy);
1010 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1012 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1014 struct ieee80211_local *local =
1015 container_of(work, struct ieee80211_local,
1016 sched_scan_stopped_work);
1018 mutex_lock(&local->mtx);
1020 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1021 mutex_unlock(&local->mtx);
1025 rcu_assign_pointer(local->sched_scan_sdata, NULL);
1027 mutex_unlock(&local->mtx);
1029 cfg80211_sched_scan_stopped(local->hw.wiphy);
1032 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1034 struct ieee80211_local *local = hw_to_local(hw);
1036 trace_api_sched_scan_stopped(local);
1038 ieee80211_queue_work(&local->hw, &local->sched_scan_stopped_work);
1040 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);