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 if (elems->tim && (!elems->parse_error ||
117 !(bss->valid_data & IEEE80211_BSS_VALID_DTIM))) {
118 struct ieee80211_tim_ie *tim_ie = elems->tim;
119 bss->dtim_period = tim_ie->dtim_period;
120 if (!elems->parse_error)
121 bss->valid_data |= IEEE80211_BSS_VALID_DTIM;
124 /* If the beacon had no TIM IE, or it was invalid, use 1 */
125 if (beacon && !bss->dtim_period)
126 bss->dtim_period = 1;
128 /* replace old supported rates if we get new values */
129 if (!elems->parse_error ||
130 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
132 if (elems->supp_rates) {
133 clen = IEEE80211_MAX_SUPP_RATES;
134 if (clen > elems->supp_rates_len)
135 clen = elems->supp_rates_len;
136 memcpy(bss->supp_rates, elems->supp_rates, clen);
139 if (elems->ext_supp_rates) {
140 clen = IEEE80211_MAX_SUPP_RATES - srlen;
141 if (clen > elems->ext_supp_rates_len)
142 clen = elems->ext_supp_rates_len;
143 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
148 bss->supp_rates_len = srlen;
149 if (!elems->parse_error)
150 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
154 if (!elems->parse_error ||
155 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
156 bss->wmm_used = elems->wmm_param || elems->wmm_info;
157 bss->uapsd_supported = is_uapsd_supported(elems);
158 if (!elems->parse_error)
159 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
163 bss->last_probe_resp = jiffies;
168 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
170 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
171 struct ieee80211_sub_if_data *sdata1, *sdata2;
172 struct ieee80211_mgmt *mgmt = (void *)skb->data;
173 struct ieee80211_bss *bss;
175 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 /* ignore ProbeResp to foreign address */
194 if ((!sdata1 || !ether_addr_equal(mgmt->da, sdata1->vif.addr)) &&
195 (!sdata2 || !ether_addr_equal(mgmt->da, sdata2->vif.addr)))
198 elements = mgmt->u.probe_resp.variable;
199 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
202 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
203 elements = mgmt->u.beacon.variable;
207 if (baselen > skb->len)
210 ieee802_11_parse_elems(elements, skb->len - baselen, &elems);
212 if (elems.ds_params && elems.ds_params_len == 1)
213 freq = ieee80211_channel_to_frequency(elems.ds_params[0],
216 freq = rx_status->freq;
218 channel = ieee80211_get_channel(local->hw.wiphy, freq);
220 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
223 bss = ieee80211_bss_info_update(local, rx_status,
224 mgmt, skb->len, &elems,
227 ieee80211_rx_bss_put(local, bss);
230 /* return false if no more work */
231 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
233 struct cfg80211_scan_request *req = local->scan_req;
234 enum ieee80211_band band;
235 int i, ielen, n_chans;
238 if (local->hw_scan_band == IEEE80211_NUM_BANDS)
241 band = local->hw_scan_band;
243 for (i = 0; i < req->n_channels; i++) {
244 if (req->channels[i]->band == band) {
245 local->hw_scan_req->channels[n_chans] =
251 local->hw_scan_band++;
254 local->hw_scan_req->n_channels = n_chans;
256 ielen = ieee80211_build_preq_ies(local, (u8 *)local->hw_scan_req->ie,
257 req->ie, req->ie_len, band,
258 req->rates[band], 0);
259 local->hw_scan_req->ie_len = ielen;
260 local->hw_scan_req->no_cck = req->no_cck;
265 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted,
268 struct ieee80211_local *local = hw_to_local(hw);
270 lockdep_assert_held(&local->mtx);
273 * It's ok to abort a not-yet-running scan (that
274 * we have one at all will be verified by checking
275 * local->scan_req next), but not to complete it
278 if (WARN_ON(!local->scanning && !aborted))
281 if (WARN_ON(!local->scan_req))
284 if (was_hw_scan && !aborted && ieee80211_prep_hw_scan(local)) {
287 rc = drv_hw_scan(local,
288 rcu_dereference_protected(local->scan_sdata,
289 lockdep_is_held(&local->mtx)),
296 kfree(local->hw_scan_req);
297 local->hw_scan_req = NULL;
299 if (local->scan_req != local->int_scan_req)
300 cfg80211_scan_done(local->scan_req, aborted);
301 local->scan_req = NULL;
302 rcu_assign_pointer(local->scan_sdata, NULL);
305 local->scan_channel = NULL;
307 /* Set power back to normal operating levels. */
308 ieee80211_hw_config(local, 0);
311 ieee80211_configure_filter(local);
312 drv_sw_scan_complete(local);
313 ieee80211_offchannel_return(local, true);
316 ieee80211_recalc_idle(local);
318 ieee80211_mlme_notify_scan_completed(local);
319 ieee80211_ibss_notify_scan_completed(local);
320 ieee80211_mesh_notify_scan_completed(local);
321 ieee80211_start_next_roc(local);
324 void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
326 struct ieee80211_local *local = hw_to_local(hw);
328 trace_api_scan_completed(local, aborted);
330 set_bit(SCAN_COMPLETED, &local->scanning);
332 set_bit(SCAN_ABORTED, &local->scanning);
333 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
335 EXPORT_SYMBOL(ieee80211_scan_completed);
337 static int ieee80211_start_sw_scan(struct ieee80211_local *local)
340 * Hardware/driver doesn't support hw_scan, so use software
341 * scanning instead. First send a nullfunc frame with power save
342 * bit on so that AP will buffer the frames for us while we are not
343 * listening, then send probe requests to each channel and wait for
344 * the responses. After all channels are scanned, tune back to the
345 * original channel and send a nullfunc frame with power save bit
346 * off to trigger the AP to send us all the buffered frames.
348 * Note that while local->sw_scanning is true everything else but
349 * nullfunc frames and probe requests will be dropped in
350 * ieee80211_tx_h_check_assoc().
352 drv_sw_scan_start(local);
354 local->leave_oper_channel_time = jiffies;
355 local->next_scan_state = SCAN_DECISION;
356 local->scan_channel_idx = 0;
358 ieee80211_offchannel_stop_vifs(local, true);
360 ieee80211_configure_filter(local);
362 /* We need to set power level at maximum rate for scanning. */
363 ieee80211_hw_config(local, 0);
365 ieee80211_queue_delayed_work(&local->hw,
366 &local->scan_work, 0);
371 static bool ieee80211_can_scan(struct ieee80211_local *local,
372 struct ieee80211_sub_if_data *sdata)
374 if (!list_empty(&local->roc_list))
377 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
378 sdata->u.mgd.flags & (IEEE80211_STA_BEACON_POLL |
379 IEEE80211_STA_CONNECTION_POLL))
385 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
387 lockdep_assert_held(&local->mtx);
389 if (!local->scan_req || local->scanning)
392 if (!ieee80211_can_scan(local,
393 rcu_dereference_protected(
395 lockdep_is_held(&local->mtx))))
398 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
399 round_jiffies_relative(0));
402 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
403 unsigned long *next_delay)
406 struct ieee80211_sub_if_data *sdata;
407 enum ieee80211_band band = local->hw.conf.channel->band;
409 sdata = rcu_dereference_protected(local->scan_sdata,
410 lockdep_is_held(&local->mtx));
412 for (i = 0; i < local->scan_req->n_ssids; i++)
413 ieee80211_send_probe_req(
415 local->scan_req->ssids[i].ssid,
416 local->scan_req->ssids[i].ssid_len,
417 local->scan_req->ie, local->scan_req->ie_len,
418 local->scan_req->rates[band], false,
419 local->scan_req->no_cck,
420 local->hw.conf.channel);
423 * After sending probe requests, wait for probe responses
426 *next_delay = IEEE80211_CHANNEL_TIME;
427 local->next_scan_state = SCAN_DECISION;
430 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
431 struct cfg80211_scan_request *req)
433 struct ieee80211_local *local = sdata->local;
436 lockdep_assert_held(&local->mtx);
441 if (!ieee80211_can_scan(local, sdata)) {
442 /* wait for the work to finish/time out */
443 local->scan_req = req;
444 rcu_assign_pointer(local->scan_sdata, sdata);
448 if (local->ops->hw_scan) {
451 local->hw_scan_req = kmalloc(
452 sizeof(*local->hw_scan_req) +
453 req->n_channels * sizeof(req->channels[0]) +
454 2 + IEEE80211_MAX_SSID_LEN + local->scan_ies_len +
455 req->ie_len, GFP_KERNEL);
456 if (!local->hw_scan_req)
459 local->hw_scan_req->ssids = req->ssids;
460 local->hw_scan_req->n_ssids = req->n_ssids;
461 ies = (u8 *)local->hw_scan_req +
462 sizeof(*local->hw_scan_req) +
463 req->n_channels * sizeof(req->channels[0]);
464 local->hw_scan_req->ie = ies;
466 local->hw_scan_band = 0;
469 * After allocating local->hw_scan_req, we must
470 * go through until ieee80211_prep_hw_scan(), so
471 * anything that might be changed here and leave
472 * this function early must not go after this
477 local->scan_req = req;
478 rcu_assign_pointer(local->scan_sdata, sdata);
480 if (local->ops->hw_scan) {
481 __set_bit(SCAN_HW_SCANNING, &local->scanning);
482 } else if ((req->n_channels == 1) &&
483 (req->channels[0] == local->oper_channel)) {
485 * If we are scanning only on the operating channel
486 * then we do not need to stop normal activities
488 unsigned long next_delay;
490 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
492 ieee80211_recalc_idle(local);
494 /* Notify driver scan is starting, keep order of operations
495 * same as normal software scan, in case that matters. */
496 drv_sw_scan_start(local);
498 ieee80211_configure_filter(local); /* accept probe-responses */
500 /* We need to ensure power level is at max for scanning. */
501 ieee80211_hw_config(local, 0);
503 if ((req->channels[0]->flags &
504 IEEE80211_CHAN_PASSIVE_SCAN) ||
505 !local->scan_req->n_ssids) {
506 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
508 ieee80211_scan_state_send_probe(local, &next_delay);
509 next_delay = IEEE80211_CHANNEL_TIME;
512 /* Now, just wait a bit and we are all done! */
513 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
517 /* Do normal software scan */
518 __set_bit(SCAN_SW_SCANNING, &local->scanning);
521 ieee80211_recalc_idle(local);
523 if (local->ops->hw_scan) {
524 WARN_ON(!ieee80211_prep_hw_scan(local));
525 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
527 rc = ieee80211_start_sw_scan(local);
530 kfree(local->hw_scan_req);
531 local->hw_scan_req = NULL;
534 ieee80211_recalc_idle(local);
536 local->scan_req = NULL;
537 rcu_assign_pointer(local->scan_sdata, NULL);
544 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
547 * TODO: channel switching also consumes quite some time,
548 * add that delay as well to get a better estimation
550 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN)
551 return IEEE80211_PASSIVE_CHANNEL_TIME;
552 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
555 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
556 unsigned long *next_delay)
558 bool associated = false;
559 bool tx_empty = true;
561 bool listen_int_exceeded;
562 unsigned long min_beacon_int = 0;
563 struct ieee80211_sub_if_data *sdata;
564 struct ieee80211_channel *next_chan;
567 * check if at least one STA interface is associated,
568 * check if at least one STA interface has pending tx frames
569 * and grab the lowest used beacon interval
571 mutex_lock(&local->iflist_mtx);
572 list_for_each_entry(sdata, &local->interfaces, list) {
573 if (!ieee80211_sdata_running(sdata))
576 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
577 if (sdata->u.mgd.associated) {
580 if (sdata->vif.bss_conf.beacon_int <
581 min_beacon_int || min_beacon_int == 0)
583 sdata->vif.bss_conf.beacon_int;
585 if (!qdisc_all_tx_empty(sdata->dev)) {
592 mutex_unlock(&local->iflist_mtx);
594 next_chan = local->scan_req->channels[local->scan_channel_idx];
597 * we're currently scanning a different channel, let's
598 * see if we can scan another channel without interfering
599 * with the current traffic situation.
601 * Since we don't know if the AP has pending frames for us
602 * we can only check for our tx queues and use the current
603 * pm_qos requirements for rx. Hence, if no tx traffic occurs
604 * at all we will scan as many channels in a row as the pm_qos
605 * latency allows us to. Additionally we also check for the
606 * currently negotiated listen interval to prevent losing
607 * frames unnecessarily.
609 * Otherwise switch back to the operating channel.
612 bad_latency = time_after(jiffies +
613 ieee80211_scan_get_channel_time(next_chan),
614 local->leave_oper_channel_time +
615 usecs_to_jiffies(pm_qos_request(PM_QOS_NETWORK_LATENCY)));
617 listen_int_exceeded = time_after(jiffies +
618 ieee80211_scan_get_channel_time(next_chan),
619 local->leave_oper_channel_time +
620 usecs_to_jiffies(min_beacon_int * 1024) *
621 local->hw.conf.listen_interval);
623 if (associated && (!tx_empty || bad_latency || listen_int_exceeded))
624 local->next_scan_state = SCAN_SUSPEND;
626 local->next_scan_state = SCAN_SET_CHANNEL;
631 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
632 unsigned long *next_delay)
635 struct ieee80211_channel *chan;
638 chan = local->scan_req->channels[local->scan_channel_idx];
640 local->scan_channel = chan;
642 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
645 /* advance state machine to next channel/band */
646 local->scan_channel_idx++;
649 /* if we skip this channel return to the decision state */
650 local->next_scan_state = SCAN_DECISION;
655 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
656 * (which unfortunately doesn't say _why_ step a) is done,
657 * but it waits for the probe delay or until a frame is
658 * received - and the received frame would update the NAV).
659 * For now, we do not support waiting until a frame is
662 * In any case, it is not necessary for a passive scan.
664 if (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN ||
665 !local->scan_req->n_ssids) {
666 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
667 local->next_scan_state = SCAN_DECISION;
671 /* active scan, send probes */
672 *next_delay = IEEE80211_PROBE_DELAY;
673 local->next_scan_state = SCAN_SEND_PROBE;
676 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
677 unsigned long *next_delay)
679 /* switch back to the operating channel */
680 local->scan_channel = NULL;
681 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
684 * Re-enable vifs and beaconing. Leave PS
685 * in off-channel state..will put that back
686 * on-channel at the end of scanning.
688 ieee80211_offchannel_return(local, false);
690 *next_delay = HZ / 5;
691 /* afterwards, resume scan & go to next channel */
692 local->next_scan_state = SCAN_RESUME;
695 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
696 unsigned long *next_delay)
698 /* PS already is in off-channel mode */
699 ieee80211_offchannel_stop_vifs(local, false);
701 if (local->ops->flush) {
702 drv_flush(local, false);
705 *next_delay = HZ / 10;
707 /* remember when we left the operating channel */
708 local->leave_oper_channel_time = jiffies;
710 /* advance to the next channel to be scanned */
711 local->next_scan_state = SCAN_SET_CHANNEL;
714 void ieee80211_scan_work(struct work_struct *work)
716 struct ieee80211_local *local =
717 container_of(work, struct ieee80211_local, scan_work.work);
718 struct ieee80211_sub_if_data *sdata;
719 unsigned long next_delay = 0;
720 bool aborted, hw_scan;
722 mutex_lock(&local->mtx);
724 sdata = rcu_dereference_protected(local->scan_sdata,
725 lockdep_is_held(&local->mtx));
727 /* When scanning on-channel, the first-callback means completed. */
728 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
729 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
733 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
734 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
738 if (!sdata || !local->scan_req)
741 if (local->scan_req && !local->scanning) {
742 struct cfg80211_scan_request *req = local->scan_req;
745 local->scan_req = NULL;
746 rcu_assign_pointer(local->scan_sdata, NULL);
748 rc = __ieee80211_start_scan(sdata, req);
750 /* need to complete scan in cfg80211 */
751 local->scan_req = req;
759 * Avoid re-scheduling when the sdata is going away.
761 if (!ieee80211_sdata_running(sdata)) {
767 * as long as no delay is required advance immediately
768 * without scheduling a new work
771 if (!ieee80211_sdata_running(sdata)) {
776 switch (local->next_scan_state) {
778 /* if no more bands/channels left, complete scan */
779 if (local->scan_channel_idx >= local->scan_req->n_channels) {
783 ieee80211_scan_state_decision(local, &next_delay);
785 case SCAN_SET_CHANNEL:
786 ieee80211_scan_state_set_channel(local, &next_delay);
788 case SCAN_SEND_PROBE:
789 ieee80211_scan_state_send_probe(local, &next_delay);
792 ieee80211_scan_state_suspend(local, &next_delay);
795 ieee80211_scan_state_resume(local, &next_delay);
798 } while (next_delay == 0);
800 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
804 hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
805 __ieee80211_scan_completed(&local->hw, aborted, hw_scan);
807 mutex_unlock(&local->mtx);
810 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
811 struct cfg80211_scan_request *req)
815 mutex_lock(&sdata->local->mtx);
816 res = __ieee80211_start_scan(sdata, req);
817 mutex_unlock(&sdata->local->mtx);
822 int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata,
823 const u8 *ssid, u8 ssid_len,
824 struct ieee80211_channel *chan)
826 struct ieee80211_local *local = sdata->local;
828 enum ieee80211_band band;
830 mutex_lock(&local->mtx);
836 /* fill internal scan request */
840 for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
841 if (!local->hw.wiphy->bands[band])
844 i < local->hw.wiphy->bands[band]->n_channels;
846 local->int_scan_req->channels[nchan] =
847 &local->hw.wiphy->bands[band]->channels[i];
852 local->int_scan_req->n_channels = nchan;
854 local->int_scan_req->channels[0] = chan;
855 local->int_scan_req->n_channels = 1;
858 local->int_scan_req->ssids = &local->scan_ssid;
859 local->int_scan_req->n_ssids = 1;
860 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
861 local->int_scan_req->ssids[0].ssid_len = ssid_len;
863 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
865 mutex_unlock(&local->mtx);
870 * Only call this function when a scan can't be queued -- under RTNL.
872 void ieee80211_scan_cancel(struct ieee80211_local *local)
875 * We are canceling software scan, or deferred scan that was not
876 * yet really started (see __ieee80211_start_scan ).
878 * Regarding hardware scan:
879 * - we can not call __ieee80211_scan_completed() as when
880 * SCAN_HW_SCANNING bit is set this function change
881 * local->hw_scan_req to operate on 5G band, what race with
882 * driver which can use local->hw_scan_req
884 * - we can not cancel scan_work since driver can schedule it
885 * by ieee80211_scan_completed(..., true) to finish scan
887 * Hence we only call the cancel_hw_scan() callback, but the low-level
888 * driver is still responsible for calling ieee80211_scan_completed()
889 * after the scan was completed/aborted.
892 mutex_lock(&local->mtx);
893 if (!local->scan_req)
896 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
897 if (local->ops->cancel_hw_scan)
898 drv_cancel_hw_scan(local,
899 rcu_dereference_protected(local->scan_sdata,
900 lockdep_is_held(&local->mtx)));
905 * If the work is currently running, it must be blocked on
906 * the mutex, but we'll set scan_sdata = NULL and it'll
907 * simply exit once it acquires the mutex.
909 cancel_delayed_work(&local->scan_work);
911 __ieee80211_scan_completed(&local->hw, true, false);
913 mutex_unlock(&local->mtx);
916 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
917 struct cfg80211_sched_scan_request *req)
919 struct ieee80211_local *local = sdata->local;
920 struct ieee80211_sched_scan_ies sched_scan_ies;
923 mutex_lock(&local->mtx);
925 if (rcu_access_pointer(local->sched_scan_sdata)) {
930 if (!local->ops->sched_scan_start) {
935 for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
936 if (!local->hw.wiphy->bands[i])
939 sched_scan_ies.ie[i] = kzalloc(2 + IEEE80211_MAX_SSID_LEN +
940 local->scan_ies_len +
943 if (!sched_scan_ies.ie[i]) {
948 sched_scan_ies.len[i] =
949 ieee80211_build_preq_ies(local, sched_scan_ies.ie[i],
950 req->ie, req->ie_len, i,
954 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
956 rcu_assign_pointer(local->sched_scan_sdata, sdata);
960 kfree(sched_scan_ies.ie[--i]);
962 mutex_unlock(&local->mtx);
966 int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata)
968 struct ieee80211_local *local = sdata->local;
971 mutex_lock(&local->mtx);
973 if (!local->ops->sched_scan_stop) {
978 if (rcu_access_pointer(local->sched_scan_sdata))
979 drv_sched_scan_stop(local, sdata);
982 mutex_unlock(&local->mtx);
987 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
989 struct ieee80211_local *local = hw_to_local(hw);
991 trace_api_sched_scan_results(local);
993 cfg80211_sched_scan_results(hw->wiphy);
995 EXPORT_SYMBOL(ieee80211_sched_scan_results);
997 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
999 struct ieee80211_local *local =
1000 container_of(work, struct ieee80211_local,
1001 sched_scan_stopped_work);
1003 mutex_lock(&local->mtx);
1005 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1006 mutex_unlock(&local->mtx);
1010 rcu_assign_pointer(local->sched_scan_sdata, NULL);
1012 mutex_unlock(&local->mtx);
1014 cfg80211_sched_scan_stopped(local->hw.wiphy);
1017 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1019 struct ieee80211_local *local = hw_to_local(hw);
1021 trace_api_sched_scan_stopped(local);
1023 ieee80211_queue_work(&local->hw, &local->sched_scan_stopped_work);
1025 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);