1 // SPDX-License-Identifier: GPL-2.0-only
3 * Scanning implementation
5 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
6 * Copyright 2004, Instant802 Networks, Inc.
7 * Copyright 2005, Devicescape Software, Inc.
8 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
9 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
10 * Copyright 2013-2015 Intel Mobile Communications GmbH
11 * Copyright 2016-2017 Intel Deutschland GmbH
12 * Copyright (C) 2018-2019 Intel Corporation
15 #include <linux/if_arp.h>
16 #include <linux/etherdevice.h>
17 #include <linux/rtnetlink.h>
18 #include <net/sch_generic.h>
19 #include <linux/slab.h>
20 #include <linux/export.h>
21 #include <linux/random.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;
59 ieee80211_update_bss_from_elems(struct ieee80211_local *local,
60 struct ieee80211_bss *bss,
61 struct ieee802_11_elems *elems,
62 struct ieee80211_rx_status *rx_status,
68 bss->device_ts_beacon = rx_status->device_timestamp;
70 bss->device_ts_presp = rx_status->device_timestamp;
72 if (elems->parse_error) {
74 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
76 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
79 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
81 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
84 /* save the ERP value so that it is available at association time */
85 if (elems->erp_info && (!elems->parse_error ||
86 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
87 bss->erp_value = elems->erp_info[0];
88 bss->has_erp_value = true;
89 if (!elems->parse_error)
90 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
93 /* replace old supported rates if we get new values */
94 if (!elems->parse_error ||
95 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
97 if (elems->supp_rates) {
98 clen = IEEE80211_MAX_SUPP_RATES;
99 if (clen > elems->supp_rates_len)
100 clen = elems->supp_rates_len;
101 memcpy(bss->supp_rates, elems->supp_rates, clen);
104 if (elems->ext_supp_rates) {
105 clen = IEEE80211_MAX_SUPP_RATES - srlen;
106 if (clen > elems->ext_supp_rates_len)
107 clen = elems->ext_supp_rates_len;
108 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
113 bss->supp_rates_len = srlen;
114 if (!elems->parse_error)
115 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
119 if (!elems->parse_error ||
120 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
121 bss->wmm_used = elems->wmm_param || elems->wmm_info;
122 bss->uapsd_supported = is_uapsd_supported(elems);
123 if (!elems->parse_error)
124 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
128 struct ieee80211_supported_band *sband =
129 local->hw.wiphy->bands[rx_status->band];
130 if (!(rx_status->encoding == RX_ENC_HT) &&
131 !(rx_status->encoding == RX_ENC_VHT))
133 &sband->bitrates[rx_status->rate_idx];
137 struct ieee80211_bss *
138 ieee80211_bss_info_update(struct ieee80211_local *local,
139 struct ieee80211_rx_status *rx_status,
140 struct ieee80211_mgmt *mgmt, size_t len,
141 struct ieee80211_channel *channel)
143 bool beacon = ieee80211_is_beacon(mgmt->frame_control);
144 struct cfg80211_bss *cbss, *non_tx_cbss;
145 struct ieee80211_bss *bss, *non_tx_bss;
146 struct cfg80211_inform_bss bss_meta = {
147 .boottime_ns = rx_status->boottime_ns,
150 struct ieee80211_sub_if_data *scan_sdata;
151 struct ieee802_11_elems elems;
155 if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
156 bss_meta.signal = 0; /* invalid signal indication */
157 else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
158 bss_meta.signal = rx_status->signal * 100;
159 else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
160 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
162 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
163 if (rx_status->bw == RATE_INFO_BW_5)
164 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
165 else if (rx_status->bw == RATE_INFO_BW_10)
166 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
168 bss_meta.chan = channel;
171 scan_sdata = rcu_dereference(local->scan_sdata);
172 if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
173 scan_sdata->vif.bss_conf.assoc &&
174 ieee80211_have_rx_timestamp(rx_status)) {
175 bss_meta.parent_tsf =
176 ieee80211_calculate_rx_timestamp(local, rx_status,
178 ether_addr_copy(bss_meta.parent_bssid,
179 scan_sdata->vif.bss_conf.bssid);
183 cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
184 mgmt, len, GFP_ATOMIC);
188 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
189 elements = mgmt->u.probe_resp.variable;
190 baselen = offsetof(struct ieee80211_mgmt,
191 u.probe_resp.variable);
193 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
194 elements = mgmt->u.beacon.variable;
200 ieee802_11_parse_elems(elements, len - baselen, false, &elems,
201 mgmt->bssid, cbss->bssid);
203 /* In case the signal is invalid update the status */
204 signal_valid = abs(channel->center_freq - cbss->channel->center_freq)
205 <= local->hw.wiphy->max_adj_channel_rssi_comp;
207 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
209 bss = (void *)cbss->priv;
210 ieee80211_update_bss_from_elems(local, bss, &elems, rx_status, beacon);
212 list_for_each_entry(non_tx_cbss, &cbss->nontrans_list, nontrans_list) {
213 non_tx_bss = (void *)non_tx_cbss->priv;
215 ieee80211_update_bss_from_elems(local, non_tx_bss, &elems,
222 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
223 u32 scan_flags, const u8 *da)
227 /* accept broadcast for OCE */
228 if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
229 is_broadcast_ether_addr(da))
231 if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
233 return ether_addr_equal(da, sdata->vif.addr);
236 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
238 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
239 struct ieee80211_sub_if_data *sdata1, *sdata2;
240 struct ieee80211_mgmt *mgmt = (void *)skb->data;
241 struct ieee80211_bss *bss;
242 struct ieee80211_channel *channel;
245 (!ieee80211_is_probe_resp(mgmt->frame_control) &&
246 !ieee80211_is_beacon(mgmt->frame_control)))
249 sdata1 = rcu_dereference(local->scan_sdata);
250 sdata2 = rcu_dereference(local->sched_scan_sdata);
252 if (likely(!sdata1 && !sdata2))
255 if (test_and_clear_bit(SCAN_BEACON_WAIT, &local->scanning)) {
257 * we were passive scanning because of radar/no-IR, but
258 * the beacon/proberesp rx gives us an opportunity to upgrade
261 set_bit(SCAN_BEACON_DONE, &local->scanning);
262 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
265 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
266 struct cfg80211_scan_request *scan_req;
267 struct cfg80211_sched_scan_request *sched_scan_req;
268 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
270 scan_req = rcu_dereference(local->scan_req);
271 sched_scan_req = rcu_dereference(local->sched_scan_req);
274 scan_req_flags = scan_req->flags;
277 sched_scan_req_flags = sched_scan_req->flags;
279 /* ignore ProbeResp to foreign address or non-bcast (OCE)
280 * unless scanning with randomised address
282 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
284 !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
289 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
291 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
294 bss = ieee80211_bss_info_update(local, rx_status,
298 ieee80211_rx_bss_put(local, bss);
302 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
303 enum nl80211_bss_scan_width scan_width)
305 memset(chandef, 0, sizeof(*chandef));
306 switch (scan_width) {
307 case NL80211_BSS_CHAN_WIDTH_5:
308 chandef->width = NL80211_CHAN_WIDTH_5;
310 case NL80211_BSS_CHAN_WIDTH_10:
311 chandef->width = NL80211_CHAN_WIDTH_10;
314 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
319 /* return false if no more work */
320 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
322 struct cfg80211_scan_request *req;
323 struct cfg80211_chan_def chandef;
325 int i, ielen, n_chans;
328 req = rcu_dereference_protected(local->scan_req,
329 lockdep_is_held(&local->mtx));
331 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
334 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
335 for (i = 0; i < req->n_channels; i++) {
336 local->hw_scan_req->req.channels[i] = req->channels[i];
337 bands_used |= BIT(req->channels[i]->band);
340 n_chans = req->n_channels;
343 if (local->hw_scan_band == NUM_NL80211_BANDS)
348 for (i = 0; i < req->n_channels; i++) {
349 if (req->channels[i]->band !=
352 local->hw_scan_req->req.channels[n_chans] =
355 bands_used |= BIT(req->channels[i]->band);
358 local->hw_scan_band++;
362 local->hw_scan_req->req.n_channels = n_chans;
363 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
365 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
366 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
368 ielen = ieee80211_build_preq_ies(local,
369 (u8 *)local->hw_scan_req->req.ie,
370 local->hw_scan_ies_bufsize,
371 &local->hw_scan_req->ies,
372 req->ie, req->ie_len,
373 bands_used, req->rates, &chandef,
375 local->hw_scan_req->req.ie_len = ielen;
376 local->hw_scan_req->req.no_cck = req->no_cck;
377 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
378 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
380 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
385 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
387 struct ieee80211_local *local = hw_to_local(hw);
388 bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
389 bool was_scanning = local->scanning;
390 struct cfg80211_scan_request *scan_req;
391 struct ieee80211_sub_if_data *scan_sdata;
392 struct ieee80211_sub_if_data *sdata;
394 lockdep_assert_held(&local->mtx);
397 * It's ok to abort a not-yet-running scan (that
398 * we have one at all will be verified by checking
399 * local->scan_req next), but not to complete it
402 if (WARN_ON(!local->scanning && !aborted))
405 if (WARN_ON(!local->scan_req))
408 if (hw_scan && !aborted &&
409 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
410 ieee80211_prep_hw_scan(local)) {
413 rc = drv_hw_scan(local,
414 rcu_dereference_protected(local->scan_sdata,
415 lockdep_is_held(&local->mtx)),
421 /* HW scan failed and is going to be reported as aborted,
422 * so clear old scan info.
424 memset(&local->scan_info, 0, sizeof(local->scan_info));
428 kfree(local->hw_scan_req);
429 local->hw_scan_req = NULL;
431 scan_req = rcu_dereference_protected(local->scan_req,
432 lockdep_is_held(&local->mtx));
434 if (scan_req != local->int_scan_req) {
435 local->scan_info.aborted = aborted;
436 cfg80211_scan_done(scan_req, &local->scan_info);
438 RCU_INIT_POINTER(local->scan_req, NULL);
440 scan_sdata = rcu_dereference_protected(local->scan_sdata,
441 lockdep_is_held(&local->mtx));
442 RCU_INIT_POINTER(local->scan_sdata, NULL);
445 local->scan_chandef.chan = NULL;
447 /* Set power back to normal operating levels. */
448 ieee80211_hw_config(local, 0);
451 ieee80211_configure_filter(local);
452 drv_sw_scan_complete(local, scan_sdata);
453 ieee80211_offchannel_return(local);
456 ieee80211_recalc_idle(local);
458 ieee80211_mlme_notify_scan_completed(local);
459 ieee80211_ibss_notify_scan_completed(local);
461 /* Requeue all the work that might have been ignored while
462 * the scan was in progress; if there was none this will
463 * just be a no-op for the particular interface.
465 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
466 if (ieee80211_sdata_running(sdata))
467 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
471 ieee80211_start_next_roc(local);
474 void ieee80211_scan_completed(struct ieee80211_hw *hw,
475 struct cfg80211_scan_info *info)
477 struct ieee80211_local *local = hw_to_local(hw);
479 trace_api_scan_completed(local, info->aborted);
481 set_bit(SCAN_COMPLETED, &local->scanning);
483 set_bit(SCAN_ABORTED, &local->scanning);
485 memcpy(&local->scan_info, info, sizeof(*info));
487 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
489 EXPORT_SYMBOL(ieee80211_scan_completed);
491 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
492 struct ieee80211_sub_if_data *sdata)
494 /* Software scan is not supported in multi-channel cases */
495 if (local->use_chanctx)
499 * Hardware/driver doesn't support hw_scan, so use software
500 * scanning instead. First send a nullfunc frame with power save
501 * bit on so that AP will buffer the frames for us while we are not
502 * listening, then send probe requests to each channel and wait for
503 * the responses. After all channels are scanned, tune back to the
504 * original channel and send a nullfunc frame with power save bit
505 * off to trigger the AP to send us all the buffered frames.
507 * Note that while local->sw_scanning is true everything else but
508 * nullfunc frames and probe requests will be dropped in
509 * ieee80211_tx_h_check_assoc().
511 drv_sw_scan_start(local, sdata, local->scan_addr);
513 local->leave_oper_channel_time = jiffies;
514 local->next_scan_state = SCAN_DECISION;
515 local->scan_channel_idx = 0;
517 ieee80211_offchannel_stop_vifs(local);
519 /* ensure nullfunc is transmitted before leaving operating channel */
520 ieee80211_flush_queues(local, NULL, false);
522 ieee80211_configure_filter(local);
524 /* We need to set power level at maximum rate for scanning. */
525 ieee80211_hw_config(local, 0);
527 ieee80211_queue_delayed_work(&local->hw,
528 &local->scan_work, 0);
533 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
535 struct ieee80211_local *local = sdata->local;
536 struct ieee80211_sub_if_data *sdata_iter;
538 if (!ieee80211_is_radar_required(local))
541 if (!regulatory_pre_cac_allowed(local->hw.wiphy))
544 mutex_lock(&local->iflist_mtx);
545 list_for_each_entry(sdata_iter, &local->interfaces, list) {
546 if (sdata_iter->wdev.cac_started) {
547 mutex_unlock(&local->iflist_mtx);
551 mutex_unlock(&local->iflist_mtx);
556 static bool ieee80211_can_scan(struct ieee80211_local *local,
557 struct ieee80211_sub_if_data *sdata)
559 if (!__ieee80211_can_leave_ch(sdata))
562 if (!list_empty(&local->roc_list))
565 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
566 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
572 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
574 lockdep_assert_held(&local->mtx);
576 if (!local->scan_req || local->scanning)
579 if (!ieee80211_can_scan(local,
580 rcu_dereference_protected(
582 lockdep_is_held(&local->mtx))))
585 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
586 round_jiffies_relative(0));
589 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
590 const u8 *src, const u8 *dst,
591 const u8 *ssid, size_t ssid_len,
592 const u8 *ie, size_t ie_len,
593 u32 ratemask, u32 flags, u32 tx_flags,
594 struct ieee80211_channel *channel)
597 u32 txdata_flags = 0;
599 skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
604 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
605 struct ieee80211_hdr *hdr = (void *)skb->data;
606 u16 sn = get_random_u32();
608 txdata_flags |= IEEE80211_TX_NO_SEQNO;
610 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
612 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
613 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band,
618 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
619 unsigned long *next_delay)
622 struct ieee80211_sub_if_data *sdata;
623 struct cfg80211_scan_request *scan_req;
624 enum nl80211_band band = local->hw.conf.chandef.chan->band;
625 u32 flags = 0, tx_flags;
627 scan_req = rcu_dereference_protected(local->scan_req,
628 lockdep_is_held(&local->mtx));
630 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
631 if (scan_req->no_cck)
632 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
633 if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
634 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
635 if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
636 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
638 sdata = rcu_dereference_protected(local->scan_sdata,
639 lockdep_is_held(&local->mtx));
641 for (i = 0; i < scan_req->n_ssids; i++)
642 ieee80211_send_scan_probe_req(
643 sdata, local->scan_addr, scan_req->bssid,
644 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
645 scan_req->ie, scan_req->ie_len,
646 scan_req->rates[band], flags,
647 tx_flags, local->hw.conf.chandef.chan);
650 * After sending probe requests, wait for probe responses
653 *next_delay = IEEE80211_CHANNEL_TIME;
654 local->next_scan_state = SCAN_DECISION;
657 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
658 struct cfg80211_scan_request *req)
660 struct ieee80211_local *local = sdata->local;
661 bool hw_scan = local->ops->hw_scan;
664 lockdep_assert_held(&local->mtx);
669 if (!__ieee80211_can_leave_ch(sdata))
672 if (!ieee80211_can_scan(local, sdata)) {
673 /* wait for the work to finish/time out */
674 rcu_assign_pointer(local->scan_req, req);
675 rcu_assign_pointer(local->scan_sdata, sdata);
683 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
685 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
687 u8 bands_counted = 0;
689 for (i = 0; i < req->n_channels; i++) {
690 if (bands_counted & BIT(req->channels[i]->band))
692 bands_counted |= BIT(req->channels[i]->band);
696 local->hw_scan_ies_bufsize *= n_bands;
699 local->hw_scan_req = kmalloc(
700 sizeof(*local->hw_scan_req) +
701 req->n_channels * sizeof(req->channels[0]) +
702 local->hw_scan_ies_bufsize, GFP_KERNEL);
703 if (!local->hw_scan_req)
706 local->hw_scan_req->req.ssids = req->ssids;
707 local->hw_scan_req->req.n_ssids = req->n_ssids;
708 ies = (u8 *)local->hw_scan_req +
709 sizeof(*local->hw_scan_req) +
710 req->n_channels * sizeof(req->channels[0]);
711 local->hw_scan_req->req.ie = ies;
712 local->hw_scan_req->req.flags = req->flags;
713 eth_broadcast_addr(local->hw_scan_req->req.bssid);
714 local->hw_scan_req->req.duration = req->duration;
715 local->hw_scan_req->req.duration_mandatory =
716 req->duration_mandatory;
718 local->hw_scan_band = 0;
721 * After allocating local->hw_scan_req, we must
722 * go through until ieee80211_prep_hw_scan(), so
723 * anything that might be changed here and leave
724 * this function early must not go after this
729 rcu_assign_pointer(local->scan_req, req);
730 rcu_assign_pointer(local->scan_sdata, sdata);
732 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
733 get_random_mask_addr(local->scan_addr,
737 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
740 __set_bit(SCAN_HW_SCANNING, &local->scanning);
741 } else if ((req->n_channels == 1) &&
742 (req->channels[0] == local->_oper_chandef.chan)) {
744 * If we are scanning only on the operating channel
745 * then we do not need to stop normal activities
747 unsigned long next_delay;
749 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
751 ieee80211_recalc_idle(local);
753 /* Notify driver scan is starting, keep order of operations
754 * same as normal software scan, in case that matters. */
755 drv_sw_scan_start(local, sdata, local->scan_addr);
757 ieee80211_configure_filter(local); /* accept probe-responses */
759 /* We need to ensure power level is at max for scanning. */
760 ieee80211_hw_config(local, 0);
762 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
763 IEEE80211_CHAN_RADAR)) ||
765 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
767 set_bit(SCAN_BEACON_WAIT, &local->scanning);
769 ieee80211_scan_state_send_probe(local, &next_delay);
770 next_delay = IEEE80211_CHANNEL_TIME;
773 /* Now, just wait a bit and we are all done! */
774 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
778 /* Do normal software scan */
779 __set_bit(SCAN_SW_SCANNING, &local->scanning);
782 ieee80211_recalc_idle(local);
785 WARN_ON(!ieee80211_prep_hw_scan(local));
786 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
788 rc = ieee80211_start_sw_scan(local, sdata);
792 kfree(local->hw_scan_req);
793 local->hw_scan_req = NULL;
796 ieee80211_recalc_idle(local);
798 local->scan_req = NULL;
799 RCU_INIT_POINTER(local->scan_sdata, NULL);
802 if (hw_scan && rc == 1) {
804 * we can't fall back to software for P2P-GO
805 * as it must update NoA etc.
807 if (ieee80211_vif_type_p2p(&sdata->vif) ==
808 NL80211_IFTYPE_P2P_GO)
818 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
821 * TODO: channel switching also consumes quite some time,
822 * add that delay as well to get a better estimation
824 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
825 return IEEE80211_PASSIVE_CHANNEL_TIME;
826 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
829 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
830 unsigned long *next_delay)
832 bool associated = false;
833 bool tx_empty = true;
835 struct ieee80211_sub_if_data *sdata;
836 struct ieee80211_channel *next_chan;
837 enum mac80211_scan_state next_scan_state;
838 struct cfg80211_scan_request *scan_req;
841 * check if at least one STA interface is associated,
842 * check if at least one STA interface has pending tx frames
843 * and grab the lowest used beacon interval
845 mutex_lock(&local->iflist_mtx);
846 list_for_each_entry(sdata, &local->interfaces, list) {
847 if (!ieee80211_sdata_running(sdata))
850 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
851 if (sdata->u.mgd.associated) {
854 if (!qdisc_all_tx_empty(sdata->dev)) {
861 mutex_unlock(&local->iflist_mtx);
863 scan_req = rcu_dereference_protected(local->scan_req,
864 lockdep_is_held(&local->mtx));
866 next_chan = scan_req->channels[local->scan_channel_idx];
869 * we're currently scanning a different channel, let's
870 * see if we can scan another channel without interfering
871 * with the current traffic situation.
873 * Keep good latency, do not stay off-channel more than 125 ms.
876 bad_latency = time_after(jiffies +
877 ieee80211_scan_get_channel_time(next_chan),
878 local->leave_oper_channel_time + HZ / 8);
880 if (associated && !tx_empty) {
881 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
882 next_scan_state = SCAN_ABORT;
884 next_scan_state = SCAN_SUSPEND;
885 } else if (associated && bad_latency) {
886 next_scan_state = SCAN_SUSPEND;
888 next_scan_state = SCAN_SET_CHANNEL;
891 local->next_scan_state = next_scan_state;
896 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
897 unsigned long *next_delay)
900 struct ieee80211_channel *chan;
901 enum nl80211_bss_scan_width oper_scan_width;
902 struct cfg80211_scan_request *scan_req;
904 scan_req = rcu_dereference_protected(local->scan_req,
905 lockdep_is_held(&local->mtx));
908 chan = scan_req->channels[local->scan_channel_idx];
910 local->scan_chandef.chan = chan;
911 local->scan_chandef.center_freq1 = chan->center_freq;
912 local->scan_chandef.center_freq2 = 0;
913 switch (scan_req->scan_width) {
914 case NL80211_BSS_CHAN_WIDTH_5:
915 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
917 case NL80211_BSS_CHAN_WIDTH_10:
918 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
920 case NL80211_BSS_CHAN_WIDTH_20:
921 /* If scanning on oper channel, use whatever channel-type
922 * is currently in use.
924 oper_scan_width = cfg80211_chandef_to_scan_width(
925 &local->_oper_chandef);
926 if (chan == local->_oper_chandef.chan &&
927 oper_scan_width == scan_req->scan_width)
928 local->scan_chandef = local->_oper_chandef;
930 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
934 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
937 /* advance state machine to next channel/band */
938 local->scan_channel_idx++;
941 /* if we skip this channel return to the decision state */
942 local->next_scan_state = SCAN_DECISION;
947 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
948 * (which unfortunately doesn't say _why_ step a) is done,
949 * but it waits for the probe delay or until a frame is
950 * received - and the received frame would update the NAV).
951 * For now, we do not support waiting until a frame is
954 * In any case, it is not necessary for a passive scan.
956 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
957 !scan_req->n_ssids) {
958 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
959 local->next_scan_state = SCAN_DECISION;
960 if (scan_req->n_ssids)
961 set_bit(SCAN_BEACON_WAIT, &local->scanning);
965 /* active scan, send probes */
966 *next_delay = IEEE80211_PROBE_DELAY;
967 local->next_scan_state = SCAN_SEND_PROBE;
970 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
971 unsigned long *next_delay)
973 /* switch back to the operating channel */
974 local->scan_chandef.chan = NULL;
975 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
978 ieee80211_offchannel_return(local);
980 *next_delay = HZ / 5;
981 /* afterwards, resume scan & go to next channel */
982 local->next_scan_state = SCAN_RESUME;
985 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
986 unsigned long *next_delay)
988 ieee80211_offchannel_stop_vifs(local);
990 if (local->ops->flush) {
991 ieee80211_flush_queues(local, NULL, false);
994 *next_delay = HZ / 10;
996 /* remember when we left the operating channel */
997 local->leave_oper_channel_time = jiffies;
999 /* advance to the next channel to be scanned */
1000 local->next_scan_state = SCAN_SET_CHANNEL;
1003 void ieee80211_scan_work(struct work_struct *work)
1005 struct ieee80211_local *local =
1006 container_of(work, struct ieee80211_local, scan_work.work);
1007 struct ieee80211_sub_if_data *sdata;
1008 struct cfg80211_scan_request *scan_req;
1009 unsigned long next_delay = 0;
1012 mutex_lock(&local->mtx);
1014 if (!ieee80211_can_run_worker(local)) {
1019 sdata = rcu_dereference_protected(local->scan_sdata,
1020 lockdep_is_held(&local->mtx));
1021 scan_req = rcu_dereference_protected(local->scan_req,
1022 lockdep_is_held(&local->mtx));
1024 /* When scanning on-channel, the first-callback means completed. */
1025 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1026 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1030 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1031 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1035 if (!sdata || !scan_req)
1038 if (!local->scanning) {
1041 RCU_INIT_POINTER(local->scan_req, NULL);
1042 RCU_INIT_POINTER(local->scan_sdata, NULL);
1044 rc = __ieee80211_start_scan(sdata, scan_req);
1046 /* need to complete scan in cfg80211 */
1047 rcu_assign_pointer(local->scan_req, scan_req);
1054 clear_bit(SCAN_BEACON_WAIT, &local->scanning);
1057 * as long as no delay is required advance immediately
1058 * without scheduling a new work
1061 if (!ieee80211_sdata_running(sdata)) {
1066 if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) &&
1067 local->next_scan_state == SCAN_DECISION)
1068 local->next_scan_state = SCAN_SEND_PROBE;
1070 switch (local->next_scan_state) {
1072 /* if no more bands/channels left, complete scan */
1073 if (local->scan_channel_idx >= scan_req->n_channels) {
1077 ieee80211_scan_state_decision(local, &next_delay);
1079 case SCAN_SET_CHANNEL:
1080 ieee80211_scan_state_set_channel(local, &next_delay);
1082 case SCAN_SEND_PROBE:
1083 ieee80211_scan_state_send_probe(local, &next_delay);
1086 ieee80211_scan_state_suspend(local, &next_delay);
1089 ieee80211_scan_state_resume(local, &next_delay);
1095 } while (next_delay == 0);
1097 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
1101 __ieee80211_scan_completed(&local->hw, aborted);
1103 mutex_unlock(&local->mtx);
1106 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1107 struct cfg80211_scan_request *req)
1111 mutex_lock(&sdata->local->mtx);
1112 res = __ieee80211_start_scan(sdata, req);
1113 mutex_unlock(&sdata->local->mtx);
1118 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1119 const u8 *ssid, u8 ssid_len,
1120 struct ieee80211_channel **channels,
1121 unsigned int n_channels,
1122 enum nl80211_bss_scan_width scan_width)
1124 struct ieee80211_local *local = sdata->local;
1125 int ret = -EBUSY, i, n_ch = 0;
1126 enum nl80211_band band;
1128 mutex_lock(&local->mtx);
1131 if (local->scan_req)
1134 /* fill internal scan request */
1138 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1139 if (!local->hw.wiphy->bands[band])
1142 max_n = local->hw.wiphy->bands[band]->n_channels;
1143 for (i = 0; i < max_n; i++) {
1144 struct ieee80211_channel *tmp_ch =
1145 &local->hw.wiphy->bands[band]->channels[i];
1147 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1148 IEEE80211_CHAN_DISABLED))
1151 local->int_scan_req->channels[n_ch] = tmp_ch;
1156 if (WARN_ON_ONCE(n_ch == 0))
1159 local->int_scan_req->n_channels = n_ch;
1161 for (i = 0; i < n_channels; i++) {
1162 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1163 IEEE80211_CHAN_DISABLED))
1166 local->int_scan_req->channels[n_ch] = channels[i];
1170 if (WARN_ON_ONCE(n_ch == 0))
1173 local->int_scan_req->n_channels = n_ch;
1176 local->int_scan_req->ssids = &local->scan_ssid;
1177 local->int_scan_req->n_ssids = 1;
1178 local->int_scan_req->scan_width = scan_width;
1179 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1180 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1182 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1184 mutex_unlock(&local->mtx);
1189 * Only call this function when a scan can't be queued -- under RTNL.
1191 void ieee80211_scan_cancel(struct ieee80211_local *local)
1194 * We are canceling software scan, or deferred scan that was not
1195 * yet really started (see __ieee80211_start_scan ).
1197 * Regarding hardware scan:
1198 * - we can not call __ieee80211_scan_completed() as when
1199 * SCAN_HW_SCANNING bit is set this function change
1200 * local->hw_scan_req to operate on 5G band, what race with
1201 * driver which can use local->hw_scan_req
1203 * - we can not cancel scan_work since driver can schedule it
1204 * by ieee80211_scan_completed(..., true) to finish scan
1206 * Hence we only call the cancel_hw_scan() callback, but the low-level
1207 * driver is still responsible for calling ieee80211_scan_completed()
1208 * after the scan was completed/aborted.
1211 mutex_lock(&local->mtx);
1212 if (!local->scan_req)
1216 * We have a scan running and the driver already reported completion,
1217 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1220 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1221 test_bit(SCAN_COMPLETED, &local->scanning)) {
1222 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1226 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1228 * Make sure that __ieee80211_scan_completed doesn't trigger a
1229 * scan on another band.
1231 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1232 if (local->ops->cancel_hw_scan)
1233 drv_cancel_hw_scan(local,
1234 rcu_dereference_protected(local->scan_sdata,
1235 lockdep_is_held(&local->mtx)));
1240 * If the work is currently running, it must be blocked on
1241 * the mutex, but we'll set scan_sdata = NULL and it'll
1242 * simply exit once it acquires the mutex.
1244 cancel_delayed_work(&local->scan_work);
1246 memset(&local->scan_info, 0, sizeof(local->scan_info));
1247 __ieee80211_scan_completed(&local->hw, true);
1249 mutex_unlock(&local->mtx);
1252 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1253 struct cfg80211_sched_scan_request *req)
1255 struct ieee80211_local *local = sdata->local;
1256 struct ieee80211_scan_ies sched_scan_ies = {};
1257 struct cfg80211_chan_def chandef;
1258 int ret, i, iebufsz, num_bands = 0;
1259 u32 rate_masks[NUM_NL80211_BANDS] = {};
1264 iebufsz = local->scan_ies_len + req->ie_len;
1266 lockdep_assert_held(&local->mtx);
1268 if (!local->ops->sched_scan_start)
1271 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1272 if (local->hw.wiphy->bands[i]) {
1273 bands_used |= BIT(i);
1274 rate_masks[i] = (u32) -1;
1279 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1280 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1282 ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1288 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1290 ieee80211_build_preq_ies(local, ie, num_bands * iebufsz,
1291 &sched_scan_ies, req->ie,
1292 req->ie_len, bands_used, rate_masks, &chandef,
1295 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1297 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1298 rcu_assign_pointer(local->sched_scan_req, req);
1305 /* Clean in case of failure after HW restart or upon resume. */
1306 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1307 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1313 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1314 struct cfg80211_sched_scan_request *req)
1316 struct ieee80211_local *local = sdata->local;
1319 mutex_lock(&local->mtx);
1321 if (rcu_access_pointer(local->sched_scan_sdata)) {
1322 mutex_unlock(&local->mtx);
1326 ret = __ieee80211_request_sched_scan_start(sdata, req);
1328 mutex_unlock(&local->mtx);
1332 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1334 struct ieee80211_sub_if_data *sched_scan_sdata;
1337 mutex_lock(&local->mtx);
1339 if (!local->ops->sched_scan_stop) {
1344 /* We don't want to restart sched scan anymore. */
1345 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1347 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1348 lockdep_is_held(&local->mtx));
1349 if (sched_scan_sdata) {
1350 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1352 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1355 mutex_unlock(&local->mtx);
1360 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1362 struct ieee80211_local *local = hw_to_local(hw);
1364 trace_api_sched_scan_results(local);
1366 cfg80211_sched_scan_results(hw->wiphy, 0);
1368 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1370 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1372 mutex_lock(&local->mtx);
1374 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1375 mutex_unlock(&local->mtx);
1379 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1381 /* If sched scan was aborted by the driver. */
1382 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1384 mutex_unlock(&local->mtx);
1386 cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1389 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1391 struct ieee80211_local *local =
1392 container_of(work, struct ieee80211_local,
1393 sched_scan_stopped_work);
1395 ieee80211_sched_scan_end(local);
1398 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1400 struct ieee80211_local *local = hw_to_local(hw);
1402 trace_api_sched_scan_stopped(local);
1405 * this shouldn't really happen, so for simplicity
1406 * simply ignore it, and let mac80211 reconfigure
1407 * the sched scan later on.
1409 if (local->in_reconfig)
1412 schedule_work(&local->sched_scan_stopped_work);
1414 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);