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) 2018-2021 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];
136 if (elems->vht_cap_elem)
138 le32_to_cpu(elems->vht_cap_elem->vht_cap_info);
140 bss->vht_cap_info = 0;
143 struct ieee80211_bss *
144 ieee80211_bss_info_update(struct ieee80211_local *local,
145 struct ieee80211_rx_status *rx_status,
146 struct ieee80211_mgmt *mgmt, size_t len,
147 struct ieee80211_channel *channel)
149 bool beacon = ieee80211_is_beacon(mgmt->frame_control) ||
150 ieee80211_is_s1g_beacon(mgmt->frame_control);
151 struct cfg80211_bss *cbss, *non_tx_cbss;
152 struct ieee80211_bss *bss, *non_tx_bss;
153 struct cfg80211_inform_bss bss_meta = {
154 .boottime_ns = rx_status->boottime_ns,
157 struct ieee80211_sub_if_data *scan_sdata;
158 struct ieee802_11_elems *elems;
162 if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
163 bss_meta.signal = 0; /* invalid signal indication */
164 else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
165 bss_meta.signal = rx_status->signal * 100;
166 else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
167 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
169 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
170 if (rx_status->bw == RATE_INFO_BW_5)
171 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
172 else if (rx_status->bw == RATE_INFO_BW_10)
173 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
175 bss_meta.chan = channel;
178 scan_sdata = rcu_dereference(local->scan_sdata);
179 if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
180 scan_sdata->vif.bss_conf.assoc &&
181 ieee80211_have_rx_timestamp(rx_status)) {
182 bss_meta.parent_tsf =
183 ieee80211_calculate_rx_timestamp(local, rx_status,
185 ether_addr_copy(bss_meta.parent_bssid,
186 scan_sdata->vif.bss_conf.bssid);
190 cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
191 mgmt, len, GFP_ATOMIC);
195 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
196 elements = mgmt->u.probe_resp.variable;
197 baselen = offsetof(struct ieee80211_mgmt,
198 u.probe_resp.variable);
199 } else if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
200 struct ieee80211_ext *ext = (void *) mgmt;
202 baselen = offsetof(struct ieee80211_ext, u.s1g_beacon.variable);
203 elements = ext->u.s1g_beacon.variable;
205 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
206 elements = mgmt->u.beacon.variable;
212 elems = ieee802_11_parse_elems(elements, len - baselen, false,
213 mgmt->bssid, cbss->bssid);
217 /* In case the signal is invalid update the status */
218 signal_valid = channel == cbss->channel;
220 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
222 bss = (void *)cbss->priv;
223 ieee80211_update_bss_from_elems(local, bss, elems, rx_status, beacon);
225 list_for_each_entry(non_tx_cbss, &cbss->nontrans_list, nontrans_list) {
226 non_tx_bss = (void *)non_tx_cbss->priv;
228 ieee80211_update_bss_from_elems(local, non_tx_bss, elems,
237 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
238 u32 scan_flags, const u8 *da)
242 /* accept broadcast for OCE */
243 if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
244 is_broadcast_ether_addr(da))
246 if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
248 return ether_addr_equal(da, sdata->vif.addr);
251 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
253 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
254 struct ieee80211_sub_if_data *sdata1, *sdata2;
255 struct ieee80211_mgmt *mgmt = (void *)skb->data;
256 struct ieee80211_bss *bss;
257 struct ieee80211_channel *channel;
258 size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
259 u.probe_resp.variable);
261 if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
262 !ieee80211_is_beacon(mgmt->frame_control) &&
263 !ieee80211_is_s1g_beacon(mgmt->frame_control))
266 if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
267 if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
268 min_hdr_len = offsetof(struct ieee80211_ext,
269 u.s1g_short_beacon.variable);
271 min_hdr_len = offsetof(struct ieee80211_ext,
275 if (skb->len < min_hdr_len)
278 sdata1 = rcu_dereference(local->scan_sdata);
279 sdata2 = rcu_dereference(local->sched_scan_sdata);
281 if (likely(!sdata1 && !sdata2))
284 if (test_and_clear_bit(SCAN_BEACON_WAIT, &local->scanning)) {
286 * we were passive scanning because of radar/no-IR, but
287 * the beacon/proberesp rx gives us an opportunity to upgrade
290 set_bit(SCAN_BEACON_DONE, &local->scanning);
291 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
294 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
295 struct cfg80211_scan_request *scan_req;
296 struct cfg80211_sched_scan_request *sched_scan_req;
297 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
299 scan_req = rcu_dereference(local->scan_req);
300 sched_scan_req = rcu_dereference(local->sched_scan_req);
303 scan_req_flags = scan_req->flags;
306 sched_scan_req_flags = sched_scan_req->flags;
308 /* ignore ProbeResp to foreign address or non-bcast (OCE)
309 * unless scanning with randomised address
311 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
313 !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
318 channel = ieee80211_get_channel_khz(local->hw.wiphy,
319 ieee80211_rx_status_to_khz(rx_status));
321 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
324 bss = ieee80211_bss_info_update(local, rx_status,
328 ieee80211_rx_bss_put(local, bss);
332 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
333 enum nl80211_bss_scan_width scan_width)
335 memset(chandef, 0, sizeof(*chandef));
336 switch (scan_width) {
337 case NL80211_BSS_CHAN_WIDTH_5:
338 chandef->width = NL80211_CHAN_WIDTH_5;
340 case NL80211_BSS_CHAN_WIDTH_10:
341 chandef->width = NL80211_CHAN_WIDTH_10;
344 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
349 /* return false if no more work */
350 static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
352 struct ieee80211_local *local = sdata->local;
353 struct cfg80211_scan_request *req;
354 struct cfg80211_chan_def chandef;
356 int i, ielen, n_chans;
359 req = rcu_dereference_protected(local->scan_req,
360 lockdep_is_held(&local->mtx));
362 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
365 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
366 for (i = 0; i < req->n_channels; i++) {
367 local->hw_scan_req->req.channels[i] = req->channels[i];
368 bands_used |= BIT(req->channels[i]->band);
371 n_chans = req->n_channels;
374 if (local->hw_scan_band == NUM_NL80211_BANDS)
379 for (i = 0; i < req->n_channels; i++) {
380 if (req->channels[i]->band !=
383 local->hw_scan_req->req.channels[n_chans] =
386 bands_used |= BIT(req->channels[i]->band);
389 local->hw_scan_band++;
393 local->hw_scan_req->req.n_channels = n_chans;
394 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
396 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
397 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
399 ielen = ieee80211_build_preq_ies(sdata,
400 (u8 *)local->hw_scan_req->req.ie,
401 local->hw_scan_ies_bufsize,
402 &local->hw_scan_req->ies,
403 req->ie, req->ie_len,
404 bands_used, req->rates, &chandef,
406 local->hw_scan_req->req.ie_len = ielen;
407 local->hw_scan_req->req.no_cck = req->no_cck;
408 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
409 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
411 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
416 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
418 struct ieee80211_local *local = hw_to_local(hw);
419 bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
420 bool was_scanning = local->scanning;
421 struct cfg80211_scan_request *scan_req;
422 struct ieee80211_sub_if_data *scan_sdata;
423 struct ieee80211_sub_if_data *sdata;
425 lockdep_assert_held(&local->mtx);
428 * It's ok to abort a not-yet-running scan (that
429 * we have one at all will be verified by checking
430 * local->scan_req next), but not to complete it
433 if (WARN_ON(!local->scanning && !aborted))
436 if (WARN_ON(!local->scan_req))
439 scan_sdata = rcu_dereference_protected(local->scan_sdata,
440 lockdep_is_held(&local->mtx));
442 if (hw_scan && !aborted &&
443 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
444 ieee80211_prep_hw_scan(scan_sdata)) {
447 rc = drv_hw_scan(local,
448 rcu_dereference_protected(local->scan_sdata,
449 lockdep_is_held(&local->mtx)),
455 /* HW scan failed and is going to be reported as aborted,
456 * so clear old scan info.
458 memset(&local->scan_info, 0, sizeof(local->scan_info));
462 kfree(local->hw_scan_req);
463 local->hw_scan_req = NULL;
465 scan_req = rcu_dereference_protected(local->scan_req,
466 lockdep_is_held(&local->mtx));
468 if (scan_req != local->int_scan_req) {
469 local->scan_info.aborted = aborted;
470 cfg80211_scan_done(scan_req, &local->scan_info);
472 RCU_INIT_POINTER(local->scan_req, NULL);
473 RCU_INIT_POINTER(local->scan_sdata, NULL);
476 local->scan_chandef.chan = NULL;
478 /* Set power back to normal operating levels. */
479 ieee80211_hw_config(local, 0);
482 ieee80211_configure_filter(local);
483 drv_sw_scan_complete(local, scan_sdata);
484 ieee80211_offchannel_return(local);
487 ieee80211_recalc_idle(local);
489 ieee80211_mlme_notify_scan_completed(local);
490 ieee80211_ibss_notify_scan_completed(local);
492 /* Requeue all the work that might have been ignored while
493 * the scan was in progress; if there was none this will
494 * just be a no-op for the particular interface.
496 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
497 if (ieee80211_sdata_running(sdata))
498 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
502 ieee80211_start_next_roc(local);
505 void ieee80211_scan_completed(struct ieee80211_hw *hw,
506 struct cfg80211_scan_info *info)
508 struct ieee80211_local *local = hw_to_local(hw);
510 trace_api_scan_completed(local, info->aborted);
512 set_bit(SCAN_COMPLETED, &local->scanning);
514 set_bit(SCAN_ABORTED, &local->scanning);
516 memcpy(&local->scan_info, info, sizeof(*info));
518 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
520 EXPORT_SYMBOL(ieee80211_scan_completed);
522 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
523 struct ieee80211_sub_if_data *sdata)
525 /* Software scan is not supported in multi-channel cases */
526 if (local->use_chanctx)
530 * Hardware/driver doesn't support hw_scan, so use software
531 * scanning instead. First send a nullfunc frame with power save
532 * bit on so that AP will buffer the frames for us while we are not
533 * listening, then send probe requests to each channel and wait for
534 * the responses. After all channels are scanned, tune back to the
535 * original channel and send a nullfunc frame with power save bit
536 * off to trigger the AP to send us all the buffered frames.
538 * Note that while local->sw_scanning is true everything else but
539 * nullfunc frames and probe requests will be dropped in
540 * ieee80211_tx_h_check_assoc().
542 drv_sw_scan_start(local, sdata, local->scan_addr);
544 local->leave_oper_channel_time = jiffies;
545 local->next_scan_state = SCAN_DECISION;
546 local->scan_channel_idx = 0;
548 ieee80211_offchannel_stop_vifs(local);
550 /* ensure nullfunc is transmitted before leaving operating channel */
551 ieee80211_flush_queues(local, NULL, false);
553 ieee80211_configure_filter(local);
555 /* We need to set power level at maximum rate for scanning. */
556 ieee80211_hw_config(local, 0);
558 ieee80211_queue_delayed_work(&local->hw,
559 &local->scan_work, 0);
564 static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
566 struct ieee80211_local *local = sdata->local;
567 struct ieee80211_sub_if_data *sdata_iter;
569 if (!ieee80211_is_radar_required(local))
572 if (!regulatory_pre_cac_allowed(local->hw.wiphy))
575 mutex_lock(&local->iflist_mtx);
576 list_for_each_entry(sdata_iter, &local->interfaces, list) {
577 if (sdata_iter->wdev.cac_started) {
578 mutex_unlock(&local->iflist_mtx);
582 mutex_unlock(&local->iflist_mtx);
587 static bool ieee80211_can_scan(struct ieee80211_local *local,
588 struct ieee80211_sub_if_data *sdata)
590 if (!__ieee80211_can_leave_ch(sdata))
593 if (!list_empty(&local->roc_list))
596 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
597 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
603 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
605 lockdep_assert_held(&local->mtx);
607 if (!local->scan_req || local->scanning)
610 if (!ieee80211_can_scan(local,
611 rcu_dereference_protected(
613 lockdep_is_held(&local->mtx))))
616 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
617 round_jiffies_relative(0));
620 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
621 const u8 *src, const u8 *dst,
622 const u8 *ssid, size_t ssid_len,
623 const u8 *ie, size_t ie_len,
624 u32 ratemask, u32 flags, u32 tx_flags,
625 struct ieee80211_channel *channel)
629 skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
634 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
635 struct ieee80211_hdr *hdr = (void *)skb->data;
636 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
637 u16 sn = get_random_u32();
639 info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
641 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
643 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
644 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
648 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
649 unsigned long *next_delay)
652 struct ieee80211_sub_if_data *sdata;
653 struct cfg80211_scan_request *scan_req;
654 enum nl80211_band band = local->hw.conf.chandef.chan->band;
655 u32 flags = 0, tx_flags;
657 scan_req = rcu_dereference_protected(local->scan_req,
658 lockdep_is_held(&local->mtx));
660 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
661 if (scan_req->no_cck)
662 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
663 if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
664 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
665 if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
666 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
668 sdata = rcu_dereference_protected(local->scan_sdata,
669 lockdep_is_held(&local->mtx));
671 for (i = 0; i < scan_req->n_ssids; i++)
672 ieee80211_send_scan_probe_req(
673 sdata, local->scan_addr, scan_req->bssid,
674 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
675 scan_req->ie, scan_req->ie_len,
676 scan_req->rates[band], flags,
677 tx_flags, local->hw.conf.chandef.chan);
680 * After sending probe requests, wait for probe responses
683 *next_delay = IEEE80211_CHANNEL_TIME;
684 local->next_scan_state = SCAN_DECISION;
687 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
688 struct cfg80211_scan_request *req)
690 struct ieee80211_local *local = sdata->local;
691 bool hw_scan = local->ops->hw_scan;
694 lockdep_assert_held(&local->mtx);
699 if (!__ieee80211_can_leave_ch(sdata))
702 if (!ieee80211_can_scan(local, sdata)) {
703 /* wait for the work to finish/time out */
704 rcu_assign_pointer(local->scan_req, req);
705 rcu_assign_pointer(local->scan_sdata, sdata);
713 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
715 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
717 u8 bands_counted = 0;
719 for (i = 0; i < req->n_channels; i++) {
720 if (bands_counted & BIT(req->channels[i]->band))
722 bands_counted |= BIT(req->channels[i]->band);
726 local->hw_scan_ies_bufsize *= n_bands;
729 local->hw_scan_req = kmalloc(
730 sizeof(*local->hw_scan_req) +
731 req->n_channels * sizeof(req->channels[0]) +
732 local->hw_scan_ies_bufsize, GFP_KERNEL);
733 if (!local->hw_scan_req)
736 local->hw_scan_req->req.ssids = req->ssids;
737 local->hw_scan_req->req.n_ssids = req->n_ssids;
738 ies = (u8 *)local->hw_scan_req +
739 sizeof(*local->hw_scan_req) +
740 req->n_channels * sizeof(req->channels[0]);
741 local->hw_scan_req->req.ie = ies;
742 local->hw_scan_req->req.flags = req->flags;
743 eth_broadcast_addr(local->hw_scan_req->req.bssid);
744 local->hw_scan_req->req.duration = req->duration;
745 local->hw_scan_req->req.duration_mandatory =
746 req->duration_mandatory;
748 local->hw_scan_band = 0;
749 local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
750 local->hw_scan_req->req.scan_6ghz_params =
751 req->scan_6ghz_params;
752 local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
755 * After allocating local->hw_scan_req, we must
756 * go through until ieee80211_prep_hw_scan(), so
757 * anything that might be changed here and leave
758 * this function early must not go after this
763 rcu_assign_pointer(local->scan_req, req);
764 rcu_assign_pointer(local->scan_sdata, sdata);
766 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
767 get_random_mask_addr(local->scan_addr,
771 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
774 __set_bit(SCAN_HW_SCANNING, &local->scanning);
775 } else if ((req->n_channels == 1) &&
776 (req->channels[0] == local->_oper_chandef.chan)) {
778 * If we are scanning only on the operating channel
779 * then we do not need to stop normal activities
781 unsigned long next_delay;
783 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
785 ieee80211_recalc_idle(local);
787 /* Notify driver scan is starting, keep order of operations
788 * same as normal software scan, in case that matters. */
789 drv_sw_scan_start(local, sdata, local->scan_addr);
791 ieee80211_configure_filter(local); /* accept probe-responses */
793 /* We need to ensure power level is at max for scanning. */
794 ieee80211_hw_config(local, 0);
796 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
797 IEEE80211_CHAN_RADAR)) ||
799 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
801 set_bit(SCAN_BEACON_WAIT, &local->scanning);
803 ieee80211_scan_state_send_probe(local, &next_delay);
804 next_delay = IEEE80211_CHANNEL_TIME;
807 /* Now, just wait a bit and we are all done! */
808 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
812 /* Do normal software scan */
813 __set_bit(SCAN_SW_SCANNING, &local->scanning);
816 ieee80211_recalc_idle(local);
819 WARN_ON(!ieee80211_prep_hw_scan(sdata));
820 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
822 rc = ieee80211_start_sw_scan(local, sdata);
826 kfree(local->hw_scan_req);
827 local->hw_scan_req = NULL;
830 ieee80211_recalc_idle(local);
832 local->scan_req = NULL;
833 RCU_INIT_POINTER(local->scan_sdata, NULL);
836 if (hw_scan && rc == 1) {
838 * we can't fall back to software for P2P-GO
839 * as it must update NoA etc.
841 if (ieee80211_vif_type_p2p(&sdata->vif) ==
842 NL80211_IFTYPE_P2P_GO)
852 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
855 * TODO: channel switching also consumes quite some time,
856 * add that delay as well to get a better estimation
858 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
859 return IEEE80211_PASSIVE_CHANNEL_TIME;
860 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
863 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
864 unsigned long *next_delay)
866 bool associated = false;
867 bool tx_empty = true;
869 struct ieee80211_sub_if_data *sdata;
870 struct ieee80211_channel *next_chan;
871 enum mac80211_scan_state next_scan_state;
872 struct cfg80211_scan_request *scan_req;
875 * check if at least one STA interface is associated,
876 * check if at least one STA interface has pending tx frames
877 * and grab the lowest used beacon interval
879 mutex_lock(&local->iflist_mtx);
880 list_for_each_entry(sdata, &local->interfaces, list) {
881 if (!ieee80211_sdata_running(sdata))
884 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
885 if (sdata->u.mgd.associated) {
888 if (!qdisc_all_tx_empty(sdata->dev)) {
895 mutex_unlock(&local->iflist_mtx);
897 scan_req = rcu_dereference_protected(local->scan_req,
898 lockdep_is_held(&local->mtx));
900 next_chan = scan_req->channels[local->scan_channel_idx];
903 * we're currently scanning a different channel, let's
904 * see if we can scan another channel without interfering
905 * with the current traffic situation.
907 * Keep good latency, do not stay off-channel more than 125 ms.
910 bad_latency = time_after(jiffies +
911 ieee80211_scan_get_channel_time(next_chan),
912 local->leave_oper_channel_time + HZ / 8);
914 if (associated && !tx_empty) {
915 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
916 next_scan_state = SCAN_ABORT;
918 next_scan_state = SCAN_SUSPEND;
919 } else if (associated && bad_latency) {
920 next_scan_state = SCAN_SUSPEND;
922 next_scan_state = SCAN_SET_CHANNEL;
925 local->next_scan_state = next_scan_state;
930 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
931 unsigned long *next_delay)
934 struct ieee80211_channel *chan;
935 enum nl80211_bss_scan_width oper_scan_width;
936 struct cfg80211_scan_request *scan_req;
938 scan_req = rcu_dereference_protected(local->scan_req,
939 lockdep_is_held(&local->mtx));
942 chan = scan_req->channels[local->scan_channel_idx];
944 local->scan_chandef.chan = chan;
945 local->scan_chandef.center_freq1 = chan->center_freq;
946 local->scan_chandef.freq1_offset = chan->freq_offset;
947 local->scan_chandef.center_freq2 = 0;
949 /* For scanning on the S1G band, ignore scan_width (which is constant
950 * across all channels) for now since channel width is specific to each
951 * channel. Detect the required channel width here and likely revisit
952 * later. Maybe scan_width could be used to build the channel scan list?
954 if (chan->band == NL80211_BAND_S1GHZ) {
955 local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
959 switch (scan_req->scan_width) {
960 case NL80211_BSS_CHAN_WIDTH_5:
961 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
963 case NL80211_BSS_CHAN_WIDTH_10:
964 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
967 case NL80211_BSS_CHAN_WIDTH_20:
968 /* If scanning on oper channel, use whatever channel-type
969 * is currently in use.
971 oper_scan_width = cfg80211_chandef_to_scan_width(
972 &local->_oper_chandef);
973 if (chan == local->_oper_chandef.chan &&
974 oper_scan_width == scan_req->scan_width)
975 local->scan_chandef = local->_oper_chandef;
977 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
979 case NL80211_BSS_CHAN_WIDTH_1:
980 case NL80211_BSS_CHAN_WIDTH_2:
981 /* shouldn't get here, S1G handled above */
987 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
990 /* advance state machine to next channel/band */
991 local->scan_channel_idx++;
994 /* if we skip this channel return to the decision state */
995 local->next_scan_state = SCAN_DECISION;
1000 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
1001 * (which unfortunately doesn't say _why_ step a) is done,
1002 * but it waits for the probe delay or until a frame is
1003 * received - and the received frame would update the NAV).
1004 * For now, we do not support waiting until a frame is
1007 * In any case, it is not necessary for a passive scan.
1009 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
1010 !scan_req->n_ssids) {
1011 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
1012 local->next_scan_state = SCAN_DECISION;
1013 if (scan_req->n_ssids)
1014 set_bit(SCAN_BEACON_WAIT, &local->scanning);
1018 /* active scan, send probes */
1019 *next_delay = IEEE80211_PROBE_DELAY;
1020 local->next_scan_state = SCAN_SEND_PROBE;
1023 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1024 unsigned long *next_delay)
1026 /* switch back to the operating channel */
1027 local->scan_chandef.chan = NULL;
1028 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
1031 ieee80211_offchannel_return(local);
1033 *next_delay = HZ / 5;
1034 /* afterwards, resume scan & go to next channel */
1035 local->next_scan_state = SCAN_RESUME;
1038 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1039 unsigned long *next_delay)
1041 ieee80211_offchannel_stop_vifs(local);
1043 if (local->ops->flush) {
1044 ieee80211_flush_queues(local, NULL, false);
1047 *next_delay = HZ / 10;
1049 /* remember when we left the operating channel */
1050 local->leave_oper_channel_time = jiffies;
1052 /* advance to the next channel to be scanned */
1053 local->next_scan_state = SCAN_SET_CHANNEL;
1056 void ieee80211_scan_work(struct work_struct *work)
1058 struct ieee80211_local *local =
1059 container_of(work, struct ieee80211_local, scan_work.work);
1060 struct ieee80211_sub_if_data *sdata;
1061 struct cfg80211_scan_request *scan_req;
1062 unsigned long next_delay = 0;
1065 mutex_lock(&local->mtx);
1067 if (!ieee80211_can_run_worker(local)) {
1072 sdata = rcu_dereference_protected(local->scan_sdata,
1073 lockdep_is_held(&local->mtx));
1074 scan_req = rcu_dereference_protected(local->scan_req,
1075 lockdep_is_held(&local->mtx));
1077 /* When scanning on-channel, the first-callback means completed. */
1078 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1079 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1083 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1084 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1088 if (!sdata || !scan_req)
1091 if (!local->scanning) {
1094 RCU_INIT_POINTER(local->scan_req, NULL);
1095 RCU_INIT_POINTER(local->scan_sdata, NULL);
1097 rc = __ieee80211_start_scan(sdata, scan_req);
1099 /* need to complete scan in cfg80211 */
1100 rcu_assign_pointer(local->scan_req, scan_req);
1107 clear_bit(SCAN_BEACON_WAIT, &local->scanning);
1110 * as long as no delay is required advance immediately
1111 * without scheduling a new work
1114 if (!ieee80211_sdata_running(sdata)) {
1119 if (test_and_clear_bit(SCAN_BEACON_DONE, &local->scanning) &&
1120 local->next_scan_state == SCAN_DECISION)
1121 local->next_scan_state = SCAN_SEND_PROBE;
1123 switch (local->next_scan_state) {
1125 /* if no more bands/channels left, complete scan */
1126 if (local->scan_channel_idx >= scan_req->n_channels) {
1130 ieee80211_scan_state_decision(local, &next_delay);
1132 case SCAN_SET_CHANNEL:
1133 ieee80211_scan_state_set_channel(local, &next_delay);
1135 case SCAN_SEND_PROBE:
1136 ieee80211_scan_state_send_probe(local, &next_delay);
1139 ieee80211_scan_state_suspend(local, &next_delay);
1142 ieee80211_scan_state_resume(local, &next_delay);
1148 } while (next_delay == 0);
1150 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
1154 __ieee80211_scan_completed(&local->hw, aborted);
1156 mutex_unlock(&local->mtx);
1159 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1160 struct cfg80211_scan_request *req)
1164 mutex_lock(&sdata->local->mtx);
1165 res = __ieee80211_start_scan(sdata, req);
1166 mutex_unlock(&sdata->local->mtx);
1171 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1172 const u8 *ssid, u8 ssid_len,
1173 struct ieee80211_channel **channels,
1174 unsigned int n_channels,
1175 enum nl80211_bss_scan_width scan_width)
1177 struct ieee80211_local *local = sdata->local;
1178 int ret = -EBUSY, i, n_ch = 0;
1179 enum nl80211_band band;
1181 mutex_lock(&local->mtx);
1184 if (local->scan_req)
1187 /* fill internal scan request */
1191 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1192 if (!local->hw.wiphy->bands[band] ||
1193 band == NL80211_BAND_6GHZ)
1196 max_n = local->hw.wiphy->bands[band]->n_channels;
1197 for (i = 0; i < max_n; i++) {
1198 struct ieee80211_channel *tmp_ch =
1199 &local->hw.wiphy->bands[band]->channels[i];
1201 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1202 IEEE80211_CHAN_DISABLED))
1205 local->int_scan_req->channels[n_ch] = tmp_ch;
1210 if (WARN_ON_ONCE(n_ch == 0))
1213 local->int_scan_req->n_channels = n_ch;
1215 for (i = 0; i < n_channels; i++) {
1216 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1217 IEEE80211_CHAN_DISABLED))
1220 local->int_scan_req->channels[n_ch] = channels[i];
1224 if (WARN_ON_ONCE(n_ch == 0))
1227 local->int_scan_req->n_channels = n_ch;
1230 local->int_scan_req->ssids = &local->scan_ssid;
1231 local->int_scan_req->n_ssids = 1;
1232 local->int_scan_req->scan_width = scan_width;
1233 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1234 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1236 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1238 mutex_unlock(&local->mtx);
1243 * Only call this function when a scan can't be queued -- under RTNL.
1245 void ieee80211_scan_cancel(struct ieee80211_local *local)
1248 * We are canceling software scan, or deferred scan that was not
1249 * yet really started (see __ieee80211_start_scan ).
1251 * Regarding hardware scan:
1252 * - we can not call __ieee80211_scan_completed() as when
1253 * SCAN_HW_SCANNING bit is set this function change
1254 * local->hw_scan_req to operate on 5G band, what race with
1255 * driver which can use local->hw_scan_req
1257 * - we can not cancel scan_work since driver can schedule it
1258 * by ieee80211_scan_completed(..., true) to finish scan
1260 * Hence we only call the cancel_hw_scan() callback, but the low-level
1261 * driver is still responsible for calling ieee80211_scan_completed()
1262 * after the scan was completed/aborted.
1265 mutex_lock(&local->mtx);
1266 if (!local->scan_req)
1270 * We have a scan running and the driver already reported completion,
1271 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1274 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1275 test_bit(SCAN_COMPLETED, &local->scanning)) {
1276 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1280 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1282 * Make sure that __ieee80211_scan_completed doesn't trigger a
1283 * scan on another band.
1285 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1286 if (local->ops->cancel_hw_scan)
1287 drv_cancel_hw_scan(local,
1288 rcu_dereference_protected(local->scan_sdata,
1289 lockdep_is_held(&local->mtx)));
1294 * If the work is currently running, it must be blocked on
1295 * the mutex, but we'll set scan_sdata = NULL and it'll
1296 * simply exit once it acquires the mutex.
1298 cancel_delayed_work(&local->scan_work);
1300 memset(&local->scan_info, 0, sizeof(local->scan_info));
1301 __ieee80211_scan_completed(&local->hw, true);
1303 mutex_unlock(&local->mtx);
1306 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1307 struct cfg80211_sched_scan_request *req)
1309 struct ieee80211_local *local = sdata->local;
1310 struct ieee80211_scan_ies sched_scan_ies = {};
1311 struct cfg80211_chan_def chandef;
1312 int ret, i, iebufsz, num_bands = 0;
1313 u32 rate_masks[NUM_NL80211_BANDS] = {};
1318 iebufsz = local->scan_ies_len + req->ie_len;
1320 lockdep_assert_held(&local->mtx);
1322 if (!local->ops->sched_scan_start)
1325 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1326 if (local->hw.wiphy->bands[i]) {
1327 bands_used |= BIT(i);
1328 rate_masks[i] = (u32) -1;
1333 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1334 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1336 ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1342 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1344 ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1345 &sched_scan_ies, req->ie,
1346 req->ie_len, bands_used, rate_masks, &chandef,
1349 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1351 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1352 rcu_assign_pointer(local->sched_scan_req, req);
1359 /* Clean in case of failure after HW restart or upon resume. */
1360 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1361 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1367 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1368 struct cfg80211_sched_scan_request *req)
1370 struct ieee80211_local *local = sdata->local;
1373 mutex_lock(&local->mtx);
1375 if (rcu_access_pointer(local->sched_scan_sdata)) {
1376 mutex_unlock(&local->mtx);
1380 ret = __ieee80211_request_sched_scan_start(sdata, req);
1382 mutex_unlock(&local->mtx);
1386 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1388 struct ieee80211_sub_if_data *sched_scan_sdata;
1391 mutex_lock(&local->mtx);
1393 if (!local->ops->sched_scan_stop) {
1398 /* We don't want to restart sched scan anymore. */
1399 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1401 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1402 lockdep_is_held(&local->mtx));
1403 if (sched_scan_sdata) {
1404 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1406 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1409 mutex_unlock(&local->mtx);
1414 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1416 struct ieee80211_local *local = hw_to_local(hw);
1418 trace_api_sched_scan_results(local);
1420 cfg80211_sched_scan_results(hw->wiphy, 0);
1422 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1424 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1426 mutex_lock(&local->mtx);
1428 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1429 mutex_unlock(&local->mtx);
1433 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1435 /* If sched scan was aborted by the driver. */
1436 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1438 mutex_unlock(&local->mtx);
1440 cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1443 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1445 struct ieee80211_local *local =
1446 container_of(work, struct ieee80211_local,
1447 sched_scan_stopped_work);
1449 ieee80211_sched_scan_end(local);
1452 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1454 struct ieee80211_local *local = hw_to_local(hw);
1456 trace_api_sched_scan_stopped(local);
1459 * this shouldn't really happen, so for simplicity
1460 * simply ignore it, and let mac80211 reconfigure
1461 * the sched scan later on.
1463 if (local->in_reconfig)
1466 schedule_work(&local->sched_scan_stopped_work);
1468 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);