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>
9 * Copyright 2013-2015 Intel Mobile Communications GmbH
10 * Copyright 2016-2017 Intel Deutschland GmbH
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
17 #include <linux/if_arp.h>
18 #include <linux/etherdevice.h>
19 #include <linux/rtnetlink.h>
20 #include <net/sch_generic.h>
21 #include <linux/slab.h>
22 #include <linux/export.h>
23 #include <linux/random.h>
24 #include <net/mac80211.h>
26 #include "ieee80211_i.h"
27 #include "driver-ops.h"
30 #define IEEE80211_PROBE_DELAY (HZ / 33)
31 #define IEEE80211_CHANNEL_TIME (HZ / 33)
32 #define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
34 void ieee80211_rx_bss_put(struct ieee80211_local *local,
35 struct ieee80211_bss *bss)
39 cfg80211_put_bss(local->hw.wiphy,
40 container_of((void *)bss, struct cfg80211_bss, priv));
43 static bool is_uapsd_supported(struct ieee802_11_elems *elems)
47 if (elems->wmm_info && elems->wmm_info_len == 7
48 && elems->wmm_info[5] == 1)
49 qos_info = elems->wmm_info[6];
50 else if (elems->wmm_param && elems->wmm_param_len == 24
51 && elems->wmm_param[5] == 1)
52 qos_info = elems->wmm_param[6];
54 /* no valid wmm information or parameter element found */
57 return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
60 struct ieee80211_bss *
61 ieee80211_bss_info_update(struct ieee80211_local *local,
62 struct ieee80211_rx_status *rx_status,
63 struct ieee80211_mgmt *mgmt, size_t len,
64 struct ieee802_11_elems *elems,
65 struct ieee80211_channel *channel)
67 bool beacon = ieee80211_is_beacon(mgmt->frame_control);
68 struct cfg80211_bss *cbss;
69 struct ieee80211_bss *bss;
71 struct cfg80211_inform_bss bss_meta = {
72 .boottime_ns = rx_status->boottime_ns,
75 struct ieee80211_sub_if_data *scan_sdata;
77 if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
78 bss_meta.signal = 0; /* invalid signal indication */
79 else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
80 bss_meta.signal = rx_status->signal * 100;
81 else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
82 bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
84 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
85 if (rx_status->bw == RATE_INFO_BW_5)
86 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
87 else if (rx_status->bw == RATE_INFO_BW_10)
88 bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
90 bss_meta.chan = channel;
93 scan_sdata = rcu_dereference(local->scan_sdata);
94 if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
95 scan_sdata->vif.bss_conf.assoc &&
96 ieee80211_have_rx_timestamp(rx_status)) {
98 ieee80211_calculate_rx_timestamp(local, rx_status,
100 ether_addr_copy(bss_meta.parent_bssid,
101 scan_sdata->vif.bss_conf.bssid);
105 cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
106 mgmt, len, GFP_ATOMIC);
109 /* In case the signal is invalid update the status */
110 signal_valid = abs(channel->center_freq - cbss->channel->center_freq)
111 <= local->hw.wiphy->max_adj_channel_rssi_comp;
113 rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
115 bss = (void *)cbss->priv;
118 bss->device_ts_beacon = rx_status->device_timestamp;
120 bss->device_ts_presp = rx_status->device_timestamp;
122 if (elems->parse_error) {
124 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
126 bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
129 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
131 bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
134 /* save the ERP value so that it is available at association time */
135 if (elems->erp_info && (!elems->parse_error ||
136 !(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
137 bss->erp_value = elems->erp_info[0];
138 bss->has_erp_value = true;
139 if (!elems->parse_error)
140 bss->valid_data |= IEEE80211_BSS_VALID_ERP;
143 /* replace old supported rates if we get new values */
144 if (!elems->parse_error ||
145 !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
147 if (elems->supp_rates) {
148 clen = IEEE80211_MAX_SUPP_RATES;
149 if (clen > elems->supp_rates_len)
150 clen = elems->supp_rates_len;
151 memcpy(bss->supp_rates, elems->supp_rates, clen);
154 if (elems->ext_supp_rates) {
155 clen = IEEE80211_MAX_SUPP_RATES - srlen;
156 if (clen > elems->ext_supp_rates_len)
157 clen = elems->ext_supp_rates_len;
158 memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
163 bss->supp_rates_len = srlen;
164 if (!elems->parse_error)
165 bss->valid_data |= IEEE80211_BSS_VALID_RATES;
169 if (!elems->parse_error ||
170 !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
171 bss->wmm_used = elems->wmm_param || elems->wmm_info;
172 bss->uapsd_supported = is_uapsd_supported(elems);
173 if (!elems->parse_error)
174 bss->valid_data |= IEEE80211_BSS_VALID_WMM;
178 struct ieee80211_supported_band *sband =
179 local->hw.wiphy->bands[rx_status->band];
180 if (!(rx_status->encoding == RX_ENC_HT) &&
181 !(rx_status->encoding == RX_ENC_VHT))
183 &sband->bitrates[rx_status->rate_idx];
189 static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
190 u32 scan_flags, const u8 *da)
194 /* accept broadcast for OCE */
195 if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
196 is_broadcast_ether_addr(da))
198 if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
200 return ether_addr_equal(da, sdata->vif.addr);
203 void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
205 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
206 struct ieee80211_sub_if_data *sdata1, *sdata2;
207 struct ieee80211_mgmt *mgmt = (void *)skb->data;
208 struct ieee80211_bss *bss;
210 struct ieee80211_channel *channel;
212 struct ieee802_11_elems elems;
215 (!ieee80211_is_probe_resp(mgmt->frame_control) &&
216 !ieee80211_is_beacon(mgmt->frame_control)))
219 sdata1 = rcu_dereference(local->scan_sdata);
220 sdata2 = rcu_dereference(local->sched_scan_sdata);
222 if (likely(!sdata1 && !sdata2))
225 if (ieee80211_is_probe_resp(mgmt->frame_control)) {
226 struct cfg80211_scan_request *scan_req;
227 struct cfg80211_sched_scan_request *sched_scan_req;
228 u32 scan_req_flags = 0, sched_scan_req_flags = 0;
230 scan_req = rcu_dereference(local->scan_req);
231 sched_scan_req = rcu_dereference(local->sched_scan_req);
234 scan_req_flags = scan_req->flags;
237 sched_scan_req_flags = sched_scan_req->flags;
239 /* ignore ProbeResp to foreign address or non-bcast (OCE)
240 * unless scanning with randomised address
242 if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
244 !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
248 elements = mgmt->u.probe_resp.variable;
249 baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
251 baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
252 elements = mgmt->u.beacon.variable;
255 if (baselen > skb->len)
258 ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems);
260 channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
262 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
265 bss = ieee80211_bss_info_update(local, rx_status,
266 mgmt, skb->len, &elems,
269 ieee80211_rx_bss_put(local, bss);
273 ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
274 enum nl80211_bss_scan_width scan_width)
276 memset(chandef, 0, sizeof(*chandef));
277 switch (scan_width) {
278 case NL80211_BSS_CHAN_WIDTH_5:
279 chandef->width = NL80211_CHAN_WIDTH_5;
281 case NL80211_BSS_CHAN_WIDTH_10:
282 chandef->width = NL80211_CHAN_WIDTH_10;
285 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
290 /* return false if no more work */
291 static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
293 struct cfg80211_scan_request *req;
294 struct cfg80211_chan_def chandef;
296 int i, ielen, n_chans;
299 req = rcu_dereference_protected(local->scan_req,
300 lockdep_is_held(&local->mtx));
302 if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
305 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
306 for (i = 0; i < req->n_channels; i++) {
307 local->hw_scan_req->req.channels[i] = req->channels[i];
308 bands_used |= BIT(req->channels[i]->band);
311 n_chans = req->n_channels;
314 if (local->hw_scan_band == NUM_NL80211_BANDS)
319 for (i = 0; i < req->n_channels; i++) {
320 if (req->channels[i]->band !=
323 local->hw_scan_req->req.channels[n_chans] =
326 bands_used |= BIT(req->channels[i]->band);
329 local->hw_scan_band++;
333 local->hw_scan_req->req.n_channels = n_chans;
334 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
336 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
337 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
339 ielen = ieee80211_build_preq_ies(local,
340 (u8 *)local->hw_scan_req->req.ie,
341 local->hw_scan_ies_bufsize,
342 &local->hw_scan_req->ies,
343 req->ie, req->ie_len,
344 bands_used, req->rates, &chandef,
346 local->hw_scan_req->req.ie_len = ielen;
347 local->hw_scan_req->req.no_cck = req->no_cck;
348 ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
349 ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
351 ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
356 static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
358 struct ieee80211_local *local = hw_to_local(hw);
359 bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
360 bool was_scanning = local->scanning;
361 struct cfg80211_scan_request *scan_req;
362 struct ieee80211_sub_if_data *scan_sdata;
363 struct ieee80211_sub_if_data *sdata;
365 lockdep_assert_held(&local->mtx);
368 * It's ok to abort a not-yet-running scan (that
369 * we have one at all will be verified by checking
370 * local->scan_req next), but not to complete it
373 if (WARN_ON(!local->scanning && !aborted))
376 if (WARN_ON(!local->scan_req))
379 if (hw_scan && !aborted &&
380 !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
381 ieee80211_prep_hw_scan(local)) {
384 rc = drv_hw_scan(local,
385 rcu_dereference_protected(local->scan_sdata,
386 lockdep_is_held(&local->mtx)),
392 /* HW scan failed and is going to be reported as aborted,
393 * so clear old scan info.
395 memset(&local->scan_info, 0, sizeof(local->scan_info));
399 kfree(local->hw_scan_req);
400 local->hw_scan_req = NULL;
402 scan_req = rcu_dereference_protected(local->scan_req,
403 lockdep_is_held(&local->mtx));
405 if (scan_req != local->int_scan_req) {
406 local->scan_info.aborted = aborted;
407 cfg80211_scan_done(scan_req, &local->scan_info);
409 RCU_INIT_POINTER(local->scan_req, NULL);
411 scan_sdata = rcu_dereference_protected(local->scan_sdata,
412 lockdep_is_held(&local->mtx));
413 RCU_INIT_POINTER(local->scan_sdata, NULL);
416 local->scan_chandef.chan = NULL;
418 /* Set power back to normal operating levels. */
419 ieee80211_hw_config(local, 0);
422 ieee80211_configure_filter(local);
423 drv_sw_scan_complete(local, scan_sdata);
424 ieee80211_offchannel_return(local);
427 ieee80211_recalc_idle(local);
429 ieee80211_mlme_notify_scan_completed(local);
430 ieee80211_ibss_notify_scan_completed(local);
432 /* Requeue all the work that might have been ignored while
433 * the scan was in progress; if there was none this will
434 * just be a no-op for the particular interface.
436 list_for_each_entry_rcu(sdata, &local->interfaces, list) {
437 if (ieee80211_sdata_running(sdata))
438 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
442 ieee80211_start_next_roc(local);
445 void ieee80211_scan_completed(struct ieee80211_hw *hw,
446 struct cfg80211_scan_info *info)
448 struct ieee80211_local *local = hw_to_local(hw);
450 trace_api_scan_completed(local, info->aborted);
452 set_bit(SCAN_COMPLETED, &local->scanning);
454 set_bit(SCAN_ABORTED, &local->scanning);
456 memcpy(&local->scan_info, info, sizeof(*info));
458 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
460 EXPORT_SYMBOL(ieee80211_scan_completed);
462 static int ieee80211_start_sw_scan(struct ieee80211_local *local,
463 struct ieee80211_sub_if_data *sdata)
465 /* Software scan is not supported in multi-channel cases */
466 if (local->use_chanctx)
470 * Hardware/driver doesn't support hw_scan, so use software
471 * scanning instead. First send a nullfunc frame with power save
472 * bit on so that AP will buffer the frames for us while we are not
473 * listening, then send probe requests to each channel and wait for
474 * the responses. After all channels are scanned, tune back to the
475 * original channel and send a nullfunc frame with power save bit
476 * off to trigger the AP to send us all the buffered frames.
478 * Note that while local->sw_scanning is true everything else but
479 * nullfunc frames and probe requests will be dropped in
480 * ieee80211_tx_h_check_assoc().
482 drv_sw_scan_start(local, sdata, local->scan_addr);
484 local->leave_oper_channel_time = jiffies;
485 local->next_scan_state = SCAN_DECISION;
486 local->scan_channel_idx = 0;
488 ieee80211_offchannel_stop_vifs(local);
490 /* ensure nullfunc is transmitted before leaving operating channel */
491 ieee80211_flush_queues(local, NULL, false);
493 ieee80211_configure_filter(local);
495 /* We need to set power level at maximum rate for scanning. */
496 ieee80211_hw_config(local, 0);
498 ieee80211_queue_delayed_work(&local->hw,
499 &local->scan_work, 0);
504 static bool ieee80211_can_scan(struct ieee80211_local *local,
505 struct ieee80211_sub_if_data *sdata)
507 if (ieee80211_is_radar_required(local))
510 if (!list_empty(&local->roc_list))
513 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
514 sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
520 void ieee80211_run_deferred_scan(struct ieee80211_local *local)
522 lockdep_assert_held(&local->mtx);
524 if (!local->scan_req || local->scanning)
527 if (!ieee80211_can_scan(local,
528 rcu_dereference_protected(
530 lockdep_is_held(&local->mtx))))
533 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
534 round_jiffies_relative(0));
537 static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
538 const u8 *src, const u8 *dst,
539 const u8 *ssid, size_t ssid_len,
540 const u8 *ie, size_t ie_len,
541 u32 ratemask, u32 flags, u32 tx_flags,
542 struct ieee80211_channel *channel)
545 u32 txdata_flags = 0;
547 skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
552 if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
553 struct ieee80211_hdr *hdr = (void *)skb->data;
554 u16 sn = get_random_u32();
556 txdata_flags |= IEEE80211_TX_NO_SEQNO;
558 cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
560 IEEE80211_SKB_CB(skb)->flags |= tx_flags;
561 ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band,
566 static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
567 unsigned long *next_delay)
570 struct ieee80211_sub_if_data *sdata;
571 struct cfg80211_scan_request *scan_req;
572 enum nl80211_band band = local->hw.conf.chandef.chan->band;
573 u32 flags = 0, tx_flags;
575 scan_req = rcu_dereference_protected(local->scan_req,
576 lockdep_is_held(&local->mtx));
578 tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
579 if (scan_req->no_cck)
580 tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
581 if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
582 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
583 if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
584 flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
586 sdata = rcu_dereference_protected(local->scan_sdata,
587 lockdep_is_held(&local->mtx));
589 for (i = 0; i < scan_req->n_ssids; i++)
590 ieee80211_send_scan_probe_req(
591 sdata, local->scan_addr, scan_req->bssid,
592 scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
593 scan_req->ie, scan_req->ie_len,
594 scan_req->rates[band], flags,
595 tx_flags, local->hw.conf.chandef.chan);
598 * After sending probe requests, wait for probe responses
601 *next_delay = IEEE80211_CHANNEL_TIME;
602 local->next_scan_state = SCAN_DECISION;
605 static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
606 struct cfg80211_scan_request *req)
608 struct ieee80211_local *local = sdata->local;
609 bool hw_scan = local->ops->hw_scan;
612 lockdep_assert_held(&local->mtx);
614 if (local->scan_req || ieee80211_is_radar_required(local))
617 if (!ieee80211_can_scan(local, sdata)) {
618 /* wait for the work to finish/time out */
619 rcu_assign_pointer(local->scan_req, req);
620 rcu_assign_pointer(local->scan_sdata, sdata);
628 local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
630 if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
632 u8 bands_counted = 0;
634 for (i = 0; i < req->n_channels; i++) {
635 if (bands_counted & BIT(req->channels[i]->band))
637 bands_counted |= BIT(req->channels[i]->band);
641 local->hw_scan_ies_bufsize *= n_bands;
644 local->hw_scan_req = kmalloc(
645 sizeof(*local->hw_scan_req) +
646 req->n_channels * sizeof(req->channels[0]) +
647 local->hw_scan_ies_bufsize, GFP_KERNEL);
648 if (!local->hw_scan_req)
651 local->hw_scan_req->req.ssids = req->ssids;
652 local->hw_scan_req->req.n_ssids = req->n_ssids;
653 ies = (u8 *)local->hw_scan_req +
654 sizeof(*local->hw_scan_req) +
655 req->n_channels * sizeof(req->channels[0]);
656 local->hw_scan_req->req.ie = ies;
657 local->hw_scan_req->req.flags = req->flags;
658 eth_broadcast_addr(local->hw_scan_req->req.bssid);
659 local->hw_scan_req->req.duration = req->duration;
660 local->hw_scan_req->req.duration_mandatory =
661 req->duration_mandatory;
663 local->hw_scan_band = 0;
666 * After allocating local->hw_scan_req, we must
667 * go through until ieee80211_prep_hw_scan(), so
668 * anything that might be changed here and leave
669 * this function early must not go after this
674 rcu_assign_pointer(local->scan_req, req);
675 rcu_assign_pointer(local->scan_sdata, sdata);
677 if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
678 get_random_mask_addr(local->scan_addr,
682 memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
685 __set_bit(SCAN_HW_SCANNING, &local->scanning);
686 } else if ((req->n_channels == 1) &&
687 (req->channels[0] == local->_oper_chandef.chan)) {
689 * If we are scanning only on the operating channel
690 * then we do not need to stop normal activities
692 unsigned long next_delay;
694 __set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
696 ieee80211_recalc_idle(local);
698 /* Notify driver scan is starting, keep order of operations
699 * same as normal software scan, in case that matters. */
700 drv_sw_scan_start(local, sdata, local->scan_addr);
702 ieee80211_configure_filter(local); /* accept probe-responses */
704 /* We need to ensure power level is at max for scanning. */
705 ieee80211_hw_config(local, 0);
707 if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
708 IEEE80211_CHAN_RADAR)) ||
710 next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
712 ieee80211_scan_state_send_probe(local, &next_delay);
713 next_delay = IEEE80211_CHANNEL_TIME;
716 /* Now, just wait a bit and we are all done! */
717 ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
721 /* Do normal software scan */
722 __set_bit(SCAN_SW_SCANNING, &local->scanning);
725 ieee80211_recalc_idle(local);
728 WARN_ON(!ieee80211_prep_hw_scan(local));
729 rc = drv_hw_scan(local, sdata, local->hw_scan_req);
731 rc = ieee80211_start_sw_scan(local, sdata);
735 kfree(local->hw_scan_req);
736 local->hw_scan_req = NULL;
739 ieee80211_recalc_idle(local);
741 local->scan_req = NULL;
742 RCU_INIT_POINTER(local->scan_sdata, NULL);
745 if (hw_scan && rc == 1) {
747 * we can't fall back to software for P2P-GO
748 * as it must update NoA etc.
750 if (ieee80211_vif_type_p2p(&sdata->vif) ==
751 NL80211_IFTYPE_P2P_GO)
761 ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
764 * TODO: channel switching also consumes quite some time,
765 * add that delay as well to get a better estimation
767 if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
768 return IEEE80211_PASSIVE_CHANNEL_TIME;
769 return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
772 static void ieee80211_scan_state_decision(struct ieee80211_local *local,
773 unsigned long *next_delay)
775 bool associated = false;
776 bool tx_empty = true;
778 struct ieee80211_sub_if_data *sdata;
779 struct ieee80211_channel *next_chan;
780 enum mac80211_scan_state next_scan_state;
781 struct cfg80211_scan_request *scan_req;
784 * check if at least one STA interface is associated,
785 * check if at least one STA interface has pending tx frames
786 * and grab the lowest used beacon interval
788 mutex_lock(&local->iflist_mtx);
789 list_for_each_entry(sdata, &local->interfaces, list) {
790 if (!ieee80211_sdata_running(sdata))
793 if (sdata->vif.type == NL80211_IFTYPE_STATION) {
794 if (sdata->u.mgd.associated) {
797 if (!qdisc_all_tx_empty(sdata->dev)) {
804 mutex_unlock(&local->iflist_mtx);
806 scan_req = rcu_dereference_protected(local->scan_req,
807 lockdep_is_held(&local->mtx));
809 next_chan = scan_req->channels[local->scan_channel_idx];
812 * we're currently scanning a different channel, let's
813 * see if we can scan another channel without interfering
814 * with the current traffic situation.
816 * Keep good latency, do not stay off-channel more than 125 ms.
819 bad_latency = time_after(jiffies +
820 ieee80211_scan_get_channel_time(next_chan),
821 local->leave_oper_channel_time + HZ / 8);
823 if (associated && !tx_empty) {
824 if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
825 next_scan_state = SCAN_ABORT;
827 next_scan_state = SCAN_SUSPEND;
828 } else if (associated && bad_latency) {
829 next_scan_state = SCAN_SUSPEND;
831 next_scan_state = SCAN_SET_CHANNEL;
834 local->next_scan_state = next_scan_state;
839 static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
840 unsigned long *next_delay)
843 struct ieee80211_channel *chan;
844 enum nl80211_bss_scan_width oper_scan_width;
845 struct cfg80211_scan_request *scan_req;
847 scan_req = rcu_dereference_protected(local->scan_req,
848 lockdep_is_held(&local->mtx));
851 chan = scan_req->channels[local->scan_channel_idx];
853 local->scan_chandef.chan = chan;
854 local->scan_chandef.center_freq1 = chan->center_freq;
855 local->scan_chandef.center_freq2 = 0;
856 switch (scan_req->scan_width) {
857 case NL80211_BSS_CHAN_WIDTH_5:
858 local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
860 case NL80211_BSS_CHAN_WIDTH_10:
861 local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
863 case NL80211_BSS_CHAN_WIDTH_20:
864 /* If scanning on oper channel, use whatever channel-type
865 * is currently in use.
867 oper_scan_width = cfg80211_chandef_to_scan_width(
868 &local->_oper_chandef);
869 if (chan == local->_oper_chandef.chan &&
870 oper_scan_width == scan_req->scan_width)
871 local->scan_chandef = local->_oper_chandef;
873 local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
877 if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
880 /* advance state machine to next channel/band */
881 local->scan_channel_idx++;
884 /* if we skip this channel return to the decision state */
885 local->next_scan_state = SCAN_DECISION;
890 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
891 * (which unfortunately doesn't say _why_ step a) is done,
892 * but it waits for the probe delay or until a frame is
893 * received - and the received frame would update the NAV).
894 * For now, we do not support waiting until a frame is
897 * In any case, it is not necessary for a passive scan.
899 if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
900 !scan_req->n_ssids) {
901 *next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
902 local->next_scan_state = SCAN_DECISION;
906 /* active scan, send probes */
907 *next_delay = IEEE80211_PROBE_DELAY;
908 local->next_scan_state = SCAN_SEND_PROBE;
911 static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
912 unsigned long *next_delay)
914 /* switch back to the operating channel */
915 local->scan_chandef.chan = NULL;
916 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
919 ieee80211_offchannel_return(local);
921 *next_delay = HZ / 5;
922 /* afterwards, resume scan & go to next channel */
923 local->next_scan_state = SCAN_RESUME;
926 static void ieee80211_scan_state_resume(struct ieee80211_local *local,
927 unsigned long *next_delay)
929 ieee80211_offchannel_stop_vifs(local);
931 if (local->ops->flush) {
932 ieee80211_flush_queues(local, NULL, false);
935 *next_delay = HZ / 10;
937 /* remember when we left the operating channel */
938 local->leave_oper_channel_time = jiffies;
940 /* advance to the next channel to be scanned */
941 local->next_scan_state = SCAN_SET_CHANNEL;
944 void ieee80211_scan_work(struct work_struct *work)
946 struct ieee80211_local *local =
947 container_of(work, struct ieee80211_local, scan_work.work);
948 struct ieee80211_sub_if_data *sdata;
949 struct cfg80211_scan_request *scan_req;
950 unsigned long next_delay = 0;
953 mutex_lock(&local->mtx);
955 if (!ieee80211_can_run_worker(local)) {
960 sdata = rcu_dereference_protected(local->scan_sdata,
961 lockdep_is_held(&local->mtx));
962 scan_req = rcu_dereference_protected(local->scan_req,
963 lockdep_is_held(&local->mtx));
965 /* When scanning on-channel, the first-callback means completed. */
966 if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
967 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
971 if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
972 aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
976 if (!sdata || !scan_req)
979 if (!local->scanning) {
982 RCU_INIT_POINTER(local->scan_req, NULL);
983 RCU_INIT_POINTER(local->scan_sdata, NULL);
985 rc = __ieee80211_start_scan(sdata, scan_req);
987 /* need to complete scan in cfg80211 */
988 rcu_assign_pointer(local->scan_req, scan_req);
996 * as long as no delay is required advance immediately
997 * without scheduling a new work
1000 if (!ieee80211_sdata_running(sdata)) {
1005 switch (local->next_scan_state) {
1007 /* if no more bands/channels left, complete scan */
1008 if (local->scan_channel_idx >= scan_req->n_channels) {
1012 ieee80211_scan_state_decision(local, &next_delay);
1014 case SCAN_SET_CHANNEL:
1015 ieee80211_scan_state_set_channel(local, &next_delay);
1017 case SCAN_SEND_PROBE:
1018 ieee80211_scan_state_send_probe(local, &next_delay);
1021 ieee80211_scan_state_suspend(local, &next_delay);
1024 ieee80211_scan_state_resume(local, &next_delay);
1030 } while (next_delay == 0);
1032 ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
1036 __ieee80211_scan_completed(&local->hw, aborted);
1038 mutex_unlock(&local->mtx);
1041 int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1042 struct cfg80211_scan_request *req)
1046 mutex_lock(&sdata->local->mtx);
1047 res = __ieee80211_start_scan(sdata, req);
1048 mutex_unlock(&sdata->local->mtx);
1053 int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1054 const u8 *ssid, u8 ssid_len,
1055 struct ieee80211_channel **channels,
1056 unsigned int n_channels,
1057 enum nl80211_bss_scan_width scan_width)
1059 struct ieee80211_local *local = sdata->local;
1060 int ret = -EBUSY, i, n_ch = 0;
1061 enum nl80211_band band;
1063 mutex_lock(&local->mtx);
1066 if (local->scan_req)
1069 /* fill internal scan request */
1073 for (band = 0; band < NUM_NL80211_BANDS; band++) {
1074 if (!local->hw.wiphy->bands[band])
1077 max_n = local->hw.wiphy->bands[band]->n_channels;
1078 for (i = 0; i < max_n; i++) {
1079 struct ieee80211_channel *tmp_ch =
1080 &local->hw.wiphy->bands[band]->channels[i];
1082 if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1083 IEEE80211_CHAN_DISABLED))
1086 local->int_scan_req->channels[n_ch] = tmp_ch;
1091 if (WARN_ON_ONCE(n_ch == 0))
1094 local->int_scan_req->n_channels = n_ch;
1096 for (i = 0; i < n_channels; i++) {
1097 if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1098 IEEE80211_CHAN_DISABLED))
1101 local->int_scan_req->channels[n_ch] = channels[i];
1105 if (WARN_ON_ONCE(n_ch == 0))
1108 local->int_scan_req->n_channels = n_ch;
1111 local->int_scan_req->ssids = &local->scan_ssid;
1112 local->int_scan_req->n_ssids = 1;
1113 local->int_scan_req->scan_width = scan_width;
1114 memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1115 local->int_scan_req->ssids[0].ssid_len = ssid_len;
1117 ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1119 mutex_unlock(&local->mtx);
1124 * Only call this function when a scan can't be queued -- under RTNL.
1126 void ieee80211_scan_cancel(struct ieee80211_local *local)
1129 * We are canceling software scan, or deferred scan that was not
1130 * yet really started (see __ieee80211_start_scan ).
1132 * Regarding hardware scan:
1133 * - we can not call __ieee80211_scan_completed() as when
1134 * SCAN_HW_SCANNING bit is set this function change
1135 * local->hw_scan_req to operate on 5G band, what race with
1136 * driver which can use local->hw_scan_req
1138 * - we can not cancel scan_work since driver can schedule it
1139 * by ieee80211_scan_completed(..., true) to finish scan
1141 * Hence we only call the cancel_hw_scan() callback, but the low-level
1142 * driver is still responsible for calling ieee80211_scan_completed()
1143 * after the scan was completed/aborted.
1146 mutex_lock(&local->mtx);
1147 if (!local->scan_req)
1151 * We have a scan running and the driver already reported completion,
1152 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1155 if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1156 test_bit(SCAN_COMPLETED, &local->scanning)) {
1157 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1161 if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1163 * Make sure that __ieee80211_scan_completed doesn't trigger a
1164 * scan on another band.
1166 set_bit(SCAN_HW_CANCELLED, &local->scanning);
1167 if (local->ops->cancel_hw_scan)
1168 drv_cancel_hw_scan(local,
1169 rcu_dereference_protected(local->scan_sdata,
1170 lockdep_is_held(&local->mtx)));
1175 * If the work is currently running, it must be blocked on
1176 * the mutex, but we'll set scan_sdata = NULL and it'll
1177 * simply exit once it acquires the mutex.
1179 cancel_delayed_work(&local->scan_work);
1181 memset(&local->scan_info, 0, sizeof(local->scan_info));
1182 __ieee80211_scan_completed(&local->hw, true);
1184 mutex_unlock(&local->mtx);
1187 int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1188 struct cfg80211_sched_scan_request *req)
1190 struct ieee80211_local *local = sdata->local;
1191 struct ieee80211_scan_ies sched_scan_ies = {};
1192 struct cfg80211_chan_def chandef;
1193 int ret, i, iebufsz, num_bands = 0;
1194 u32 rate_masks[NUM_NL80211_BANDS] = {};
1199 iebufsz = local->scan_ies_len + req->ie_len;
1201 lockdep_assert_held(&local->mtx);
1203 if (!local->ops->sched_scan_start)
1206 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1207 if (local->hw.wiphy->bands[i]) {
1208 bands_used |= BIT(i);
1209 rate_masks[i] = (u32) -1;
1214 if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1215 flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1217 ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1223 ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1225 ieee80211_build_preq_ies(local, ie, num_bands * iebufsz,
1226 &sched_scan_ies, req->ie,
1227 req->ie_len, bands_used, rate_masks, &chandef,
1230 ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1232 rcu_assign_pointer(local->sched_scan_sdata, sdata);
1233 rcu_assign_pointer(local->sched_scan_req, req);
1240 /* Clean in case of failure after HW restart or upon resume. */
1241 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1242 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1248 int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1249 struct cfg80211_sched_scan_request *req)
1251 struct ieee80211_local *local = sdata->local;
1254 mutex_lock(&local->mtx);
1256 if (rcu_access_pointer(local->sched_scan_sdata)) {
1257 mutex_unlock(&local->mtx);
1261 ret = __ieee80211_request_sched_scan_start(sdata, req);
1263 mutex_unlock(&local->mtx);
1267 int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1269 struct ieee80211_sub_if_data *sched_scan_sdata;
1272 mutex_lock(&local->mtx);
1274 if (!local->ops->sched_scan_stop) {
1279 /* We don't want to restart sched scan anymore. */
1280 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1282 sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1283 lockdep_is_held(&local->mtx));
1284 if (sched_scan_sdata) {
1285 ret = drv_sched_scan_stop(local, sched_scan_sdata);
1287 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1290 mutex_unlock(&local->mtx);
1295 void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1297 struct ieee80211_local *local = hw_to_local(hw);
1299 trace_api_sched_scan_results(local);
1301 cfg80211_sched_scan_results(hw->wiphy, 0);
1303 EXPORT_SYMBOL(ieee80211_sched_scan_results);
1305 void ieee80211_sched_scan_end(struct ieee80211_local *local)
1307 mutex_lock(&local->mtx);
1309 if (!rcu_access_pointer(local->sched_scan_sdata)) {
1310 mutex_unlock(&local->mtx);
1314 RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1316 /* If sched scan was aborted by the driver. */
1317 RCU_INIT_POINTER(local->sched_scan_req, NULL);
1319 mutex_unlock(&local->mtx);
1321 cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1324 void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1326 struct ieee80211_local *local =
1327 container_of(work, struct ieee80211_local,
1328 sched_scan_stopped_work);
1330 ieee80211_sched_scan_end(local);
1333 void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1335 struct ieee80211_local *local = hw_to_local(hw);
1337 trace_api_sched_scan_stopped(local);
1340 * this shouldn't really happen, so for simplicity
1341 * simply ignore it, and let mac80211 reconfigure
1342 * the sched scan later on.
1344 if (local->in_reconfig)
1347 schedule_work(&local->sched_scan_stopped_work);
1349 EXPORT_SYMBOL(ieee80211_sched_scan_stopped);