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v5.14.15
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Scanning implementation
   4 *
   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) 2018-2020 Intel Corporation
 
 
 
  13 */
  14
  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>
  23
  24#include "ieee80211_i.h"
  25#include "driver-ops.h"
  26#include "mesh.h"
  27
  28#define IEEE80211_PROBE_DELAY (HZ / 33)
  29#define IEEE80211_CHANNEL_TIME (HZ / 33)
  30#define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
  31
  32void ieee80211_rx_bss_put(struct ieee80211_local *local,
  33			  struct ieee80211_bss *bss)
  34{
  35	if (!bss)
  36		return;
  37	cfg80211_put_bss(local->hw.wiphy,
  38			 container_of((void *)bss, struct cfg80211_bss, priv));
  39}
  40
  41static bool is_uapsd_supported(struct ieee802_11_elems *elems)
  42{
  43	u8 qos_info;
  44
  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];
  51	else
  52		/* no valid wmm information or parameter element found */
  53		return false;
  54
  55	return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
  56}
  57
  58static void
  59ieee80211_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,
  63				bool beacon)
  64{
 
 
 
  65	int clen, srlen;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  66
  67	if (beacon)
  68		bss->device_ts_beacon = rx_status->device_timestamp;
  69	else
  70		bss->device_ts_presp = rx_status->device_timestamp;
  71
  72	if (elems->parse_error) {
  73		if (beacon)
  74			bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
  75		else
  76			bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
  77	} else {
  78		if (beacon)
  79			bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
  80		else
  81			bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
  82	}
  83
  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;
  91	}
  92
  93	/* replace old supported rates if we get new values */
  94	if (!elems->parse_error ||
  95	    !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
  96		srlen = 0;
  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);
 102			srlen += clen;
 103		}
 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,
 109			       clen);
 110			srlen += clen;
 111		}
 112		if (srlen) {
 113			bss->supp_rates_len = srlen;
 114			if (!elems->parse_error)
 115				bss->valid_data |= IEEE80211_BSS_VALID_RATES;
 116		}
 117	}
 118
 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;
 125	}
 126
 127	if (beacon) {
 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))
 132			bss->beacon_rate =
 133				&sband->bitrates[rx_status->rate_idx];
 134	}
 135
 136	if (elems->vht_cap_elem)
 137		bss->vht_cap_info =
 138			le32_to_cpu(elems->vht_cap_elem->vht_cap_info);
 139	else
 140		bss->vht_cap_info = 0;
 141}
 142
 143struct ieee80211_bss *
 144ieee80211_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)
 148{
 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,
 155	};
 156	bool signal_valid;
 157	struct ieee80211_sub_if_data *scan_sdata;
 158	struct ieee802_11_elems elems;
 159	size_t baselen;
 160	u8 *elements;
 161
 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;
 168
 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;
 174
 175	bss_meta.chan = channel;
 176
 177	rcu_read_lock();
 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,
 184							 len + FCS_LEN, 24);
 185		ether_addr_copy(bss_meta.parent_bssid,
 186				scan_sdata->vif.bss_conf.bssid);
 187	}
 188	rcu_read_unlock();
 189
 190	cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
 191					      mgmt, len, GFP_ATOMIC);
 192	if (!cbss)
 193		return NULL;
 194
 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;
 201
 202		baselen = offsetof(struct ieee80211_ext, u.s1g_beacon.variable);
 203		elements = ext->u.s1g_beacon.variable;
 204	} else {
 205		baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
 206		elements = mgmt->u.beacon.variable;
 207	}
 208
 209	if (baselen > len)
 210		return NULL;
 211
 212	ieee802_11_parse_elems(elements, len - baselen, false, &elems,
 213			       mgmt->bssid, cbss->bssid);
 214
 215	/* In case the signal is invalid update the status */
 216	signal_valid = channel == cbss->channel;
 217	if (!signal_valid)
 218		rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
 219
 220	bss = (void *)cbss->priv;
 221	ieee80211_update_bss_from_elems(local, bss, &elems, rx_status, beacon);
 222
 223	list_for_each_entry(non_tx_cbss, &cbss->nontrans_list, nontrans_list) {
 224		non_tx_bss = (void *)non_tx_cbss->priv;
 225
 226		ieee80211_update_bss_from_elems(local, non_tx_bss, &elems,
 227						rx_status, beacon);
 228	}
 229
 230	return bss;
 231}
 232
 233static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
 234					u32 scan_flags, const u8 *da)
 235{
 236	if (!sdata)
 237		return false;
 238	/* accept broadcast for OCE */
 239	if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
 240	    is_broadcast_ether_addr(da))
 241		return true;
 242	if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
 243		return true;
 244	return ether_addr_equal(da, sdata->vif.addr);
 245}
 246
 247void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
 248{
 249	struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
 250	struct ieee80211_sub_if_data *sdata1, *sdata2;
 251	struct ieee80211_mgmt *mgmt = (void *)skb->data;
 252	struct ieee80211_bss *bss;
 
 253	struct ieee80211_channel *channel;
 254	size_t min_hdr_len = offsetof(struct ieee80211_mgmt,
 255				      u.probe_resp.variable);
 256
 257	if (!ieee80211_is_probe_resp(mgmt->frame_control) &&
 258	    !ieee80211_is_beacon(mgmt->frame_control) &&
 259	    !ieee80211_is_s1g_beacon(mgmt->frame_control))
 260		return;
 261
 262	if (ieee80211_is_s1g_beacon(mgmt->frame_control)) {
 263		if (ieee80211_is_s1g_short_beacon(mgmt->frame_control))
 264			min_hdr_len = offsetof(struct ieee80211_ext,
 265					       u.s1g_short_beacon.variable);
 266		else
 267			min_hdr_len = offsetof(struct ieee80211_ext,
 268					       u.s1g_beacon);
 269	}
 270
 271	if (skb->len < min_hdr_len)
 
 
 272		return;
 273
 274	sdata1 = rcu_dereference(local->scan_sdata);
 275	sdata2 = rcu_dereference(local->sched_scan_sdata);
 276
 277	if (likely(!sdata1 && !sdata2))
 278		return;
 279
 280	if (ieee80211_is_probe_resp(mgmt->frame_control)) {
 281		struct cfg80211_scan_request *scan_req;
 282		struct cfg80211_sched_scan_request *sched_scan_req;
 283		u32 scan_req_flags = 0, sched_scan_req_flags = 0;
 284
 285		scan_req = rcu_dereference(local->scan_req);
 286		sched_scan_req = rcu_dereference(local->sched_scan_req);
 287
 288		if (scan_req)
 289			scan_req_flags = scan_req->flags;
 290
 291		if (sched_scan_req)
 292			sched_scan_req_flags = sched_scan_req->flags;
 293
 294		/* ignore ProbeResp to foreign address or non-bcast (OCE)
 295		 * unless scanning with randomised address
 296		 */
 297		if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
 298						 mgmt->da) &&
 299		    !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
 300						 mgmt->da))
 301			return;
 
 
 
 
 
 
 302	}
 303
 304	channel = ieee80211_get_channel_khz(local->hw.wiphy,
 305					ieee80211_rx_status_to_khz(rx_status));
 
 
 
 
 306
 307	if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 308		return;
 309
 310	bss = ieee80211_bss_info_update(local, rx_status,
 311					mgmt, skb->len,
 312					channel);
 313	if (bss)
 314		ieee80211_rx_bss_put(local, bss);
 315}
 316
 317static void
 318ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
 319			       enum nl80211_bss_scan_width scan_width)
 320{
 321	memset(chandef, 0, sizeof(*chandef));
 322	switch (scan_width) {
 323	case NL80211_BSS_CHAN_WIDTH_5:
 324		chandef->width = NL80211_CHAN_WIDTH_5;
 325		break;
 326	case NL80211_BSS_CHAN_WIDTH_10:
 327		chandef->width = NL80211_CHAN_WIDTH_10;
 328		break;
 329	default:
 330		chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
 331		break;
 332	}
 333}
 334
 335/* return false if no more work */
 336static bool ieee80211_prep_hw_scan(struct ieee80211_sub_if_data *sdata)
 337{
 338	struct ieee80211_local *local = sdata->local;
 339	struct cfg80211_scan_request *req;
 340	struct cfg80211_chan_def chandef;
 341	u8 bands_used = 0;
 342	int i, ielen, n_chans;
 343	u32 flags = 0;
 344
 345	req = rcu_dereference_protected(local->scan_req,
 346					lockdep_is_held(&local->mtx));
 347
 348	if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
 349		return false;
 350
 351	if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
 352		for (i = 0; i < req->n_channels; i++) {
 353			local->hw_scan_req->req.channels[i] = req->channels[i];
 354			bands_used |= BIT(req->channels[i]->band);
 355		}
 356
 357		n_chans = req->n_channels;
 358	} else {
 359		do {
 360			if (local->hw_scan_band == NUM_NL80211_BANDS)
 361				return false;
 362
 363			n_chans = 0;
 364
 365			for (i = 0; i < req->n_channels; i++) {
 366				if (req->channels[i]->band !=
 367				    local->hw_scan_band)
 368					continue;
 369				local->hw_scan_req->req.channels[n_chans] =
 370							req->channels[i];
 371				n_chans++;
 372				bands_used |= BIT(req->channels[i]->band);
 373			}
 374
 375			local->hw_scan_band++;
 376		} while (!n_chans);
 377	}
 378
 379	local->hw_scan_req->req.n_channels = n_chans;
 380	ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
 381
 382	if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
 383		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
 384
 385	ielen = ieee80211_build_preq_ies(sdata,
 386					 (u8 *)local->hw_scan_req->req.ie,
 387					 local->hw_scan_ies_bufsize,
 388					 &local->hw_scan_req->ies,
 389					 req->ie, req->ie_len,
 390					 bands_used, req->rates, &chandef,
 391					 flags);
 392	local->hw_scan_req->req.ie_len = ielen;
 393	local->hw_scan_req->req.no_cck = req->no_cck;
 394	ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
 395	ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
 396			req->mac_addr_mask);
 397	ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
 398
 399	return true;
 400}
 401
 402static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
 403{
 404	struct ieee80211_local *local = hw_to_local(hw);
 405	bool hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning);
 406	bool was_scanning = local->scanning;
 407	struct cfg80211_scan_request *scan_req;
 408	struct ieee80211_sub_if_data *scan_sdata;
 409	struct ieee80211_sub_if_data *sdata;
 410
 411	lockdep_assert_held(&local->mtx);
 412
 413	/*
 414	 * It's ok to abort a not-yet-running scan (that
 415	 * we have one at all will be verified by checking
 416	 * local->scan_req next), but not to complete it
 417	 * successfully.
 418	 */
 419	if (WARN_ON(!local->scanning && !aborted))
 420		aborted = true;
 421
 422	if (WARN_ON(!local->scan_req))
 423		return;
 424
 425	scan_sdata = rcu_dereference_protected(local->scan_sdata,
 426					       lockdep_is_held(&local->mtx));
 427
 428	if (hw_scan && !aborted &&
 429	    !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
 430	    ieee80211_prep_hw_scan(scan_sdata)) {
 431		int rc;
 432
 433		rc = drv_hw_scan(local,
 434			rcu_dereference_protected(local->scan_sdata,
 435						  lockdep_is_held(&local->mtx)),
 436			local->hw_scan_req);
 437
 438		if (rc == 0)
 439			return;
 440
 441		/* HW scan failed and is going to be reported as aborted,
 442		 * so clear old scan info.
 443		 */
 444		memset(&local->scan_info, 0, sizeof(local->scan_info));
 445		aborted = true;
 446	}
 447
 448	kfree(local->hw_scan_req);
 449	local->hw_scan_req = NULL;
 450
 451	scan_req = rcu_dereference_protected(local->scan_req,
 452					     lockdep_is_held(&local->mtx));
 453
 454	if (scan_req != local->int_scan_req) {
 455		local->scan_info.aborted = aborted;
 456		cfg80211_scan_done(scan_req, &local->scan_info);
 457	}
 458	RCU_INIT_POINTER(local->scan_req, NULL);
 
 
 
 459	RCU_INIT_POINTER(local->scan_sdata, NULL);
 460
 461	local->scanning = 0;
 462	local->scan_chandef.chan = NULL;
 463
 464	/* Set power back to normal operating levels. */
 465	ieee80211_hw_config(local, 0);
 466
 467	if (!hw_scan) {
 468		ieee80211_configure_filter(local);
 469		drv_sw_scan_complete(local, scan_sdata);
 470		ieee80211_offchannel_return(local);
 471	}
 472
 473	ieee80211_recalc_idle(local);
 474
 475	ieee80211_mlme_notify_scan_completed(local);
 476	ieee80211_ibss_notify_scan_completed(local);
 477
 478	/* Requeue all the work that might have been ignored while
 479	 * the scan was in progress; if there was none this will
 480	 * just be a no-op for the particular interface.
 481	 */
 482	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 483		if (ieee80211_sdata_running(sdata))
 484			ieee80211_queue_work(&sdata->local->hw, &sdata->work);
 485	}
 486
 487	if (was_scanning)
 488		ieee80211_start_next_roc(local);
 489}
 490
 491void ieee80211_scan_completed(struct ieee80211_hw *hw,
 492			      struct cfg80211_scan_info *info)
 493{
 494	struct ieee80211_local *local = hw_to_local(hw);
 495
 496	trace_api_scan_completed(local, info->aborted);
 497
 498	set_bit(SCAN_COMPLETED, &local->scanning);
 499	if (info->aborted)
 500		set_bit(SCAN_ABORTED, &local->scanning);
 501
 502	memcpy(&local->scan_info, info, sizeof(*info));
 503
 504	ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
 505}
 506EXPORT_SYMBOL(ieee80211_scan_completed);
 507
 508static int ieee80211_start_sw_scan(struct ieee80211_local *local,
 509				   struct ieee80211_sub_if_data *sdata)
 510{
 511	/* Software scan is not supported in multi-channel cases */
 512	if (local->use_chanctx)
 513		return -EOPNOTSUPP;
 514
 515	/*
 516	 * Hardware/driver doesn't support hw_scan, so use software
 517	 * scanning instead. First send a nullfunc frame with power save
 518	 * bit on so that AP will buffer the frames for us while we are not
 519	 * listening, then send probe requests to each channel and wait for
 520	 * the responses. After all channels are scanned, tune back to the
 521	 * original channel and send a nullfunc frame with power save bit
 522	 * off to trigger the AP to send us all the buffered frames.
 523	 *
 524	 * Note that while local->sw_scanning is true everything else but
 525	 * nullfunc frames and probe requests will be dropped in
 526	 * ieee80211_tx_h_check_assoc().
 527	 */
 528	drv_sw_scan_start(local, sdata, local->scan_addr);
 529
 530	local->leave_oper_channel_time = jiffies;
 531	local->next_scan_state = SCAN_DECISION;
 532	local->scan_channel_idx = 0;
 533
 534	ieee80211_offchannel_stop_vifs(local);
 535
 536	/* ensure nullfunc is transmitted before leaving operating channel */
 537	ieee80211_flush_queues(local, NULL, false);
 538
 539	ieee80211_configure_filter(local);
 540
 541	/* We need to set power level at maximum rate for scanning. */
 542	ieee80211_hw_config(local, 0);
 543
 544	ieee80211_queue_delayed_work(&local->hw,
 545				     &local->scan_work, 0);
 546
 547	return 0;
 548}
 549
 550static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
 551{
 552	struct ieee80211_local *local = sdata->local;
 553	struct ieee80211_sub_if_data *sdata_iter;
 554
 555	if (!ieee80211_is_radar_required(local))
 556		return true;
 557
 558	if (!regulatory_pre_cac_allowed(local->hw.wiphy))
 559		return false;
 560
 561	mutex_lock(&local->iflist_mtx);
 562	list_for_each_entry(sdata_iter, &local->interfaces, list) {
 563		if (sdata_iter->wdev.cac_started) {
 564			mutex_unlock(&local->iflist_mtx);
 565			return false;
 566		}
 567	}
 568	mutex_unlock(&local->iflist_mtx);
 569
 570	return true;
 571}
 572
 573static bool ieee80211_can_scan(struct ieee80211_local *local,
 574			       struct ieee80211_sub_if_data *sdata)
 575{
 576	if (!__ieee80211_can_leave_ch(sdata))
 577		return false;
 578
 579	if (!list_empty(&local->roc_list))
 580		return false;
 581
 582	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
 583	    sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
 584		return false;
 585
 586	return true;
 587}
 588
 589void ieee80211_run_deferred_scan(struct ieee80211_local *local)
 590{
 591	lockdep_assert_held(&local->mtx);
 592
 593	if (!local->scan_req || local->scanning)
 594		return;
 595
 596	if (!ieee80211_can_scan(local,
 597				rcu_dereference_protected(
 598					local->scan_sdata,
 599					lockdep_is_held(&local->mtx))))
 600		return;
 601
 602	ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
 603				     round_jiffies_relative(0));
 604}
 605
 606static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
 607					  const u8 *src, const u8 *dst,
 608					  const u8 *ssid, size_t ssid_len,
 609					  const u8 *ie, size_t ie_len,
 610					  u32 ratemask, u32 flags, u32 tx_flags,
 611					  struct ieee80211_channel *channel)
 612{
 613	struct sk_buff *skb;
 614
 615	skb = ieee80211_build_probe_req(sdata, src, dst, ratemask, channel,
 616					ssid, ssid_len,
 617					ie, ie_len, flags);
 618
 619	if (skb) {
 620		if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
 621			struct ieee80211_hdr *hdr = (void *)skb->data;
 622			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 623			u16 sn = get_random_u32();
 624
 625			info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
 626			hdr->seq_ctrl =
 627				cpu_to_le16(IEEE80211_SN_TO_SEQ(sn));
 628		}
 629		IEEE80211_SKB_CB(skb)->flags |= tx_flags;
 630		ieee80211_tx_skb_tid_band(sdata, skb, 7, channel->band);
 631	}
 632}
 633
 634static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
 635					    unsigned long *next_delay)
 636{
 637	int i;
 638	struct ieee80211_sub_if_data *sdata;
 639	struct cfg80211_scan_request *scan_req;
 640	enum nl80211_band band = local->hw.conf.chandef.chan->band;
 641	u32 flags = 0, tx_flags;
 642
 643	scan_req = rcu_dereference_protected(local->scan_req,
 644					     lockdep_is_held(&local->mtx));
 645
 646	tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
 647	if (scan_req->no_cck)
 648		tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
 649	if (scan_req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
 650		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
 651	if (scan_req->flags & NL80211_SCAN_FLAG_RANDOM_SN)
 652		flags |= IEEE80211_PROBE_FLAG_RANDOM_SN;
 653
 654	sdata = rcu_dereference_protected(local->scan_sdata,
 655					  lockdep_is_held(&local->mtx));
 656
 657	for (i = 0; i < scan_req->n_ssids; i++)
 658		ieee80211_send_scan_probe_req(
 659			sdata, local->scan_addr, scan_req->bssid,
 660			scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
 661			scan_req->ie, scan_req->ie_len,
 662			scan_req->rates[band], flags,
 663			tx_flags, local->hw.conf.chandef.chan);
 664
 665	/*
 666	 * After sending probe requests, wait for probe responses
 667	 * on the channel.
 668	 */
 669	*next_delay = IEEE80211_CHANNEL_TIME;
 670	local->next_scan_state = SCAN_DECISION;
 671}
 672
 673static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
 674				  struct cfg80211_scan_request *req)
 675{
 676	struct ieee80211_local *local = sdata->local;
 677	bool hw_scan = local->ops->hw_scan;
 678	int rc;
 679
 680	lockdep_assert_held(&local->mtx);
 681
 682	if (local->scan_req)
 683		return -EBUSY;
 684
 685	if (!__ieee80211_can_leave_ch(sdata))
 686		return -EBUSY;
 687
 688	if (!ieee80211_can_scan(local, sdata)) {
 689		/* wait for the work to finish/time out */
 690		rcu_assign_pointer(local->scan_req, req);
 691		rcu_assign_pointer(local->scan_sdata, sdata);
 692		return 0;
 693	}
 694
 695 again:
 696	if (hw_scan) {
 697		u8 *ies;
 698
 699		local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
 700
 701		if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
 702			int i, n_bands = 0;
 703			u8 bands_counted = 0;
 704
 705			for (i = 0; i < req->n_channels; i++) {
 706				if (bands_counted & BIT(req->channels[i]->band))
 707					continue;
 708				bands_counted |= BIT(req->channels[i]->band);
 709				n_bands++;
 710			}
 711
 712			local->hw_scan_ies_bufsize *= n_bands;
 713		}
 714
 715		local->hw_scan_req = kmalloc(
 716				sizeof(*local->hw_scan_req) +
 717				req->n_channels * sizeof(req->channels[0]) +
 718				local->hw_scan_ies_bufsize, GFP_KERNEL);
 719		if (!local->hw_scan_req)
 720			return -ENOMEM;
 721
 722		local->hw_scan_req->req.ssids = req->ssids;
 723		local->hw_scan_req->req.n_ssids = req->n_ssids;
 724		ies = (u8 *)local->hw_scan_req +
 725			sizeof(*local->hw_scan_req) +
 726			req->n_channels * sizeof(req->channels[0]);
 727		local->hw_scan_req->req.ie = ies;
 728		local->hw_scan_req->req.flags = req->flags;
 729		eth_broadcast_addr(local->hw_scan_req->req.bssid);
 730		local->hw_scan_req->req.duration = req->duration;
 731		local->hw_scan_req->req.duration_mandatory =
 732			req->duration_mandatory;
 733
 734		local->hw_scan_band = 0;
 735		local->hw_scan_req->req.n_6ghz_params = req->n_6ghz_params;
 736		local->hw_scan_req->req.scan_6ghz_params =
 737			req->scan_6ghz_params;
 738		local->hw_scan_req->req.scan_6ghz = req->scan_6ghz;
 739
 740		/*
 741		 * After allocating local->hw_scan_req, we must
 742		 * go through until ieee80211_prep_hw_scan(), so
 743		 * anything that might be changed here and leave
 744		 * this function early must not go after this
 745		 * allocation.
 746		 */
 747	}
 748
 749	rcu_assign_pointer(local->scan_req, req);
 750	rcu_assign_pointer(local->scan_sdata, sdata);
 751
 752	if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
 753		get_random_mask_addr(local->scan_addr,
 754				     req->mac_addr,
 755				     req->mac_addr_mask);
 756	else
 757		memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
 758
 759	if (hw_scan) {
 760		__set_bit(SCAN_HW_SCANNING, &local->scanning);
 761	} else if ((req->n_channels == 1) &&
 762		   (req->channels[0] == local->_oper_chandef.chan)) {
 763		/*
 764		 * If we are scanning only on the operating channel
 765		 * then we do not need to stop normal activities
 766		 */
 767		unsigned long next_delay;
 768
 769		__set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
 770
 771		ieee80211_recalc_idle(local);
 772
 773		/* Notify driver scan is starting, keep order of operations
 774		 * same as normal software scan, in case that matters. */
 775		drv_sw_scan_start(local, sdata, local->scan_addr);
 776
 777		ieee80211_configure_filter(local); /* accept probe-responses */
 778
 779		/* We need to ensure power level is at max for scanning. */
 780		ieee80211_hw_config(local, 0);
 781
 782		if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
 783						IEEE80211_CHAN_RADAR)) ||
 784		    !req->n_ssids) {
 785			next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
 786		} else {
 787			ieee80211_scan_state_send_probe(local, &next_delay);
 788			next_delay = IEEE80211_CHANNEL_TIME;
 789		}
 790
 791		/* Now, just wait a bit and we are all done! */
 792		ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
 793					     next_delay);
 794		return 0;
 795	} else {
 796		/* Do normal software scan */
 797		__set_bit(SCAN_SW_SCANNING, &local->scanning);
 798	}
 799
 800	ieee80211_recalc_idle(local);
 801
 802	if (hw_scan) {
 803		WARN_ON(!ieee80211_prep_hw_scan(sdata));
 804		rc = drv_hw_scan(local, sdata, local->hw_scan_req);
 805	} else {
 806		rc = ieee80211_start_sw_scan(local, sdata);
 807	}
 808
 809	if (rc) {
 810		kfree(local->hw_scan_req);
 811		local->hw_scan_req = NULL;
 812		local->scanning = 0;
 813
 814		ieee80211_recalc_idle(local);
 815
 816		local->scan_req = NULL;
 817		RCU_INIT_POINTER(local->scan_sdata, NULL);
 818	}
 819
 820	if (hw_scan && rc == 1) {
 821		/*
 822		 * we can't fall back to software for P2P-GO
 823		 * as it must update NoA etc.
 824		 */
 825		if (ieee80211_vif_type_p2p(&sdata->vif) ==
 826				NL80211_IFTYPE_P2P_GO)
 827			return -EOPNOTSUPP;
 828		hw_scan = false;
 829		goto again;
 830	}
 831
 832	return rc;
 833}
 834
 835static unsigned long
 836ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
 837{
 838	/*
 839	 * TODO: channel switching also consumes quite some time,
 840	 * add that delay as well to get a better estimation
 841	 */
 842	if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
 843		return IEEE80211_PASSIVE_CHANNEL_TIME;
 844	return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
 845}
 846
 847static void ieee80211_scan_state_decision(struct ieee80211_local *local,
 848					  unsigned long *next_delay)
 849{
 850	bool associated = false;
 851	bool tx_empty = true;
 852	bool bad_latency;
 853	struct ieee80211_sub_if_data *sdata;
 854	struct ieee80211_channel *next_chan;
 855	enum mac80211_scan_state next_scan_state;
 856	struct cfg80211_scan_request *scan_req;
 857
 858	/*
 859	 * check if at least one STA interface is associated,
 860	 * check if at least one STA interface has pending tx frames
 861	 * and grab the lowest used beacon interval
 862	 */
 863	mutex_lock(&local->iflist_mtx);
 864	list_for_each_entry(sdata, &local->interfaces, list) {
 865		if (!ieee80211_sdata_running(sdata))
 866			continue;
 867
 868		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 869			if (sdata->u.mgd.associated) {
 870				associated = true;
 871
 872				if (!qdisc_all_tx_empty(sdata->dev)) {
 873					tx_empty = false;
 874					break;
 875				}
 876			}
 877		}
 878	}
 879	mutex_unlock(&local->iflist_mtx);
 880
 881	scan_req = rcu_dereference_protected(local->scan_req,
 882					     lockdep_is_held(&local->mtx));
 883
 884	next_chan = scan_req->channels[local->scan_channel_idx];
 885
 886	/*
 887	 * we're currently scanning a different channel, let's
 888	 * see if we can scan another channel without interfering
 889	 * with the current traffic situation.
 890	 *
 891	 * Keep good latency, do not stay off-channel more than 125 ms.
 892	 */
 893
 894	bad_latency = time_after(jiffies +
 895				 ieee80211_scan_get_channel_time(next_chan),
 896				 local->leave_oper_channel_time + HZ / 8);
 897
 898	if (associated && !tx_empty) {
 899		if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
 900			next_scan_state = SCAN_ABORT;
 901		else
 902			next_scan_state = SCAN_SUSPEND;
 903	} else if (associated && bad_latency) {
 904		next_scan_state = SCAN_SUSPEND;
 905	} else {
 906		next_scan_state = SCAN_SET_CHANNEL;
 907	}
 908
 909	local->next_scan_state = next_scan_state;
 910
 911	*next_delay = 0;
 912}
 913
 914static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
 915					     unsigned long *next_delay)
 916{
 917	int skip;
 918	struct ieee80211_channel *chan;
 919	enum nl80211_bss_scan_width oper_scan_width;
 920	struct cfg80211_scan_request *scan_req;
 921
 922	scan_req = rcu_dereference_protected(local->scan_req,
 923					     lockdep_is_held(&local->mtx));
 924
 925	skip = 0;
 926	chan = scan_req->channels[local->scan_channel_idx];
 927
 928	local->scan_chandef.chan = chan;
 929	local->scan_chandef.center_freq1 = chan->center_freq;
 930	local->scan_chandef.freq1_offset = chan->freq_offset;
 931	local->scan_chandef.center_freq2 = 0;
 932
 933	/* For scanning on the S1G band, ignore scan_width (which is constant
 934	 * across all channels) for now since channel width is specific to each
 935	 * channel. Detect the required channel width here and likely revisit
 936	 * later. Maybe scan_width could be used to build the channel scan list?
 937	 */
 938	if (chan->band == NL80211_BAND_S1GHZ) {
 939		local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
 940		goto set_channel;
 941	}
 942
 943	switch (scan_req->scan_width) {
 944	case NL80211_BSS_CHAN_WIDTH_5:
 945		local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
 946		break;
 947	case NL80211_BSS_CHAN_WIDTH_10:
 948		local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
 949		break;
 950	default:
 951	case NL80211_BSS_CHAN_WIDTH_20:
 952		/* If scanning on oper channel, use whatever channel-type
 953		 * is currently in use.
 954		 */
 955		oper_scan_width = cfg80211_chandef_to_scan_width(
 956					&local->_oper_chandef);
 957		if (chan == local->_oper_chandef.chan &&
 958		    oper_scan_width == scan_req->scan_width)
 959			local->scan_chandef = local->_oper_chandef;
 960		else
 961			local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
 962		break;
 963	case NL80211_BSS_CHAN_WIDTH_1:
 964	case NL80211_BSS_CHAN_WIDTH_2:
 965		/* shouldn't get here, S1G handled above */
 966		WARN_ON(1);
 967		break;
 968	}
 969
 970set_channel:
 971	if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
 972		skip = 1;
 973
 974	/* advance state machine to next channel/band */
 975	local->scan_channel_idx++;
 976
 977	if (skip) {
 978		/* if we skip this channel return to the decision state */
 979		local->next_scan_state = SCAN_DECISION;
 980		return;
 981	}
 982
 983	/*
 984	 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
 985	 * (which unfortunately doesn't say _why_ step a) is done,
 986	 * but it waits for the probe delay or until a frame is
 987	 * received - and the received frame would update the NAV).
 988	 * For now, we do not support waiting until a frame is
 989	 * received.
 990	 *
 991	 * In any case, it is not necessary for a passive scan.
 992	 */
 993	if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
 994	    !scan_req->n_ssids) {
 995		*next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
 996		local->next_scan_state = SCAN_DECISION;
 997		return;
 998	}
 999
1000	/* active scan, send probes */
1001	*next_delay = IEEE80211_PROBE_DELAY;
1002	local->next_scan_state = SCAN_SEND_PROBE;
1003}
1004
1005static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
1006					 unsigned long *next_delay)
1007{
1008	/* switch back to the operating channel */
1009	local->scan_chandef.chan = NULL;
1010	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
1011
1012	/* disable PS */
1013	ieee80211_offchannel_return(local);
1014
1015	*next_delay = HZ / 5;
1016	/* afterwards, resume scan & go to next channel */
1017	local->next_scan_state = SCAN_RESUME;
1018}
1019
1020static void ieee80211_scan_state_resume(struct ieee80211_local *local,
1021					unsigned long *next_delay)
1022{
1023	ieee80211_offchannel_stop_vifs(local);
1024
1025	if (local->ops->flush) {
1026		ieee80211_flush_queues(local, NULL, false);
1027		*next_delay = 0;
1028	} else
1029		*next_delay = HZ / 10;
1030
1031	/* remember when we left the operating channel */
1032	local->leave_oper_channel_time = jiffies;
1033
1034	/* advance to the next channel to be scanned */
1035	local->next_scan_state = SCAN_SET_CHANNEL;
1036}
1037
1038void ieee80211_scan_work(struct work_struct *work)
1039{
1040	struct ieee80211_local *local =
1041		container_of(work, struct ieee80211_local, scan_work.work);
1042	struct ieee80211_sub_if_data *sdata;
1043	struct cfg80211_scan_request *scan_req;
1044	unsigned long next_delay = 0;
1045	bool aborted;
1046
1047	mutex_lock(&local->mtx);
1048
1049	if (!ieee80211_can_run_worker(local)) {
1050		aborted = true;
1051		goto out_complete;
1052	}
1053
1054	sdata = rcu_dereference_protected(local->scan_sdata,
1055					  lockdep_is_held(&local->mtx));
1056	scan_req = rcu_dereference_protected(local->scan_req,
1057					     lockdep_is_held(&local->mtx));
1058
1059	/* When scanning on-channel, the first-callback means completed. */
1060	if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
1061		aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1062		goto out_complete;
1063	}
1064
1065	if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
1066		aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
1067		goto out_complete;
1068	}
1069
1070	if (!sdata || !scan_req)
1071		goto out;
1072
1073	if (!local->scanning) {
1074		int rc;
1075
1076		RCU_INIT_POINTER(local->scan_req, NULL);
1077		RCU_INIT_POINTER(local->scan_sdata, NULL);
1078
1079		rc = __ieee80211_start_scan(sdata, scan_req);
1080		if (rc) {
1081			/* need to complete scan in cfg80211 */
1082			rcu_assign_pointer(local->scan_req, scan_req);
1083			aborted = true;
1084			goto out_complete;
1085		} else
1086			goto out;
1087	}
1088
1089	/*
1090	 * as long as no delay is required advance immediately
1091	 * without scheduling a new work
1092	 */
1093	do {
1094		if (!ieee80211_sdata_running(sdata)) {
1095			aborted = true;
1096			goto out_complete;
1097		}
1098
1099		switch (local->next_scan_state) {
1100		case SCAN_DECISION:
1101			/* if no more bands/channels left, complete scan */
1102			if (local->scan_channel_idx >= scan_req->n_channels) {
1103				aborted = false;
1104				goto out_complete;
1105			}
1106			ieee80211_scan_state_decision(local, &next_delay);
1107			break;
1108		case SCAN_SET_CHANNEL:
1109			ieee80211_scan_state_set_channel(local, &next_delay);
1110			break;
1111		case SCAN_SEND_PROBE:
1112			ieee80211_scan_state_send_probe(local, &next_delay);
1113			break;
1114		case SCAN_SUSPEND:
1115			ieee80211_scan_state_suspend(local, &next_delay);
1116			break;
1117		case SCAN_RESUME:
1118			ieee80211_scan_state_resume(local, &next_delay);
1119			break;
1120		case SCAN_ABORT:
1121			aborted = true;
1122			goto out_complete;
1123		}
1124	} while (next_delay == 0);
1125
1126	ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
1127	goto out;
1128
1129out_complete:
1130	__ieee80211_scan_completed(&local->hw, aborted);
1131out:
1132	mutex_unlock(&local->mtx);
1133}
1134
1135int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
1136			   struct cfg80211_scan_request *req)
1137{
1138	int res;
1139
1140	mutex_lock(&sdata->local->mtx);
1141	res = __ieee80211_start_scan(sdata, req);
1142	mutex_unlock(&sdata->local->mtx);
1143
1144	return res;
1145}
1146
1147int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1148				const u8 *ssid, u8 ssid_len,
1149				struct ieee80211_channel **channels,
1150				unsigned int n_channels,
1151				enum nl80211_bss_scan_width scan_width)
1152{
1153	struct ieee80211_local *local = sdata->local;
1154	int ret = -EBUSY, i, n_ch = 0;
1155	enum nl80211_band band;
1156
1157	mutex_lock(&local->mtx);
1158
1159	/* busy scanning */
1160	if (local->scan_req)
1161		goto unlock;
1162
1163	/* fill internal scan request */
1164	if (!channels) {
1165		int max_n;
1166
1167		for (band = 0; band < NUM_NL80211_BANDS; band++) {
1168			if (!local->hw.wiphy->bands[band] ||
1169			    band == NL80211_BAND_6GHZ)
1170				continue;
1171
1172			max_n = local->hw.wiphy->bands[band]->n_channels;
1173			for (i = 0; i < max_n; i++) {
1174				struct ieee80211_channel *tmp_ch =
1175				    &local->hw.wiphy->bands[band]->channels[i];
1176
1177				if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1178						     IEEE80211_CHAN_DISABLED))
1179					continue;
1180
1181				local->int_scan_req->channels[n_ch] = tmp_ch;
1182				n_ch++;
1183			}
1184		}
1185
1186		if (WARN_ON_ONCE(n_ch == 0))
1187			goto unlock;
1188
1189		local->int_scan_req->n_channels = n_ch;
1190	} else {
1191		for (i = 0; i < n_channels; i++) {
1192			if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1193						  IEEE80211_CHAN_DISABLED))
1194				continue;
1195
1196			local->int_scan_req->channels[n_ch] = channels[i];
1197			n_ch++;
1198		}
1199
1200		if (WARN_ON_ONCE(n_ch == 0))
1201			goto unlock;
1202
1203		local->int_scan_req->n_channels = n_ch;
1204	}
1205
1206	local->int_scan_req->ssids = &local->scan_ssid;
1207	local->int_scan_req->n_ssids = 1;
1208	local->int_scan_req->scan_width = scan_width;
1209	memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1210	local->int_scan_req->ssids[0].ssid_len = ssid_len;
1211
1212	ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1213 unlock:
1214	mutex_unlock(&local->mtx);
1215	return ret;
1216}
1217
1218/*
1219 * Only call this function when a scan can't be queued -- under RTNL.
1220 */
1221void ieee80211_scan_cancel(struct ieee80211_local *local)
1222{
1223	/*
1224	 * We are canceling software scan, or deferred scan that was not
1225	 * yet really started (see __ieee80211_start_scan ).
1226	 *
1227	 * Regarding hardware scan:
1228	 * - we can not call  __ieee80211_scan_completed() as when
1229	 *   SCAN_HW_SCANNING bit is set this function change
1230	 *   local->hw_scan_req to operate on 5G band, what race with
1231	 *   driver which can use local->hw_scan_req
1232	 *
1233	 * - we can not cancel scan_work since driver can schedule it
1234	 *   by ieee80211_scan_completed(..., true) to finish scan
1235	 *
1236	 * Hence we only call the cancel_hw_scan() callback, but the low-level
1237	 * driver is still responsible for calling ieee80211_scan_completed()
1238	 * after the scan was completed/aborted.
1239	 */
1240
1241	mutex_lock(&local->mtx);
1242	if (!local->scan_req)
1243		goto out;
1244
1245	/*
1246	 * We have a scan running and the driver already reported completion,
1247	 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1248	 * cancelled.
1249	 */
1250	if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1251	    test_bit(SCAN_COMPLETED, &local->scanning)) {
1252		set_bit(SCAN_HW_CANCELLED, &local->scanning);
1253		goto out;
1254	}
1255
1256	if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1257		/*
1258		 * Make sure that __ieee80211_scan_completed doesn't trigger a
1259		 * scan on another band.
1260		 */
1261		set_bit(SCAN_HW_CANCELLED, &local->scanning);
1262		if (local->ops->cancel_hw_scan)
1263			drv_cancel_hw_scan(local,
1264				rcu_dereference_protected(local->scan_sdata,
1265						lockdep_is_held(&local->mtx)));
1266		goto out;
1267	}
1268
1269	/*
1270	 * If the work is currently running, it must be blocked on
1271	 * the mutex, but we'll set scan_sdata = NULL and it'll
1272	 * simply exit once it acquires the mutex.
1273	 */
1274	cancel_delayed_work(&local->scan_work);
1275	/* and clean up */
1276	memset(&local->scan_info, 0, sizeof(local->scan_info));
1277	__ieee80211_scan_completed(&local->hw, true);
1278out:
1279	mutex_unlock(&local->mtx);
1280}
1281
1282int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1283					struct cfg80211_sched_scan_request *req)
1284{
1285	struct ieee80211_local *local = sdata->local;
1286	struct ieee80211_scan_ies sched_scan_ies = {};
1287	struct cfg80211_chan_def chandef;
1288	int ret, i, iebufsz, num_bands = 0;
1289	u32 rate_masks[NUM_NL80211_BANDS] = {};
1290	u8 bands_used = 0;
1291	u8 *ie;
1292	u32 flags = 0;
1293
1294	iebufsz = local->scan_ies_len + req->ie_len;
1295
1296	lockdep_assert_held(&local->mtx);
1297
1298	if (!local->ops->sched_scan_start)
1299		return -ENOTSUPP;
1300
1301	for (i = 0; i < NUM_NL80211_BANDS; i++) {
1302		if (local->hw.wiphy->bands[i]) {
1303			bands_used |= BIT(i);
1304			rate_masks[i] = (u32) -1;
1305			num_bands++;
1306		}
1307	}
1308
1309	if (req->flags & NL80211_SCAN_FLAG_MIN_PREQ_CONTENT)
1310		flags |= IEEE80211_PROBE_FLAG_MIN_CONTENT;
1311
1312	ie = kcalloc(iebufsz, num_bands, GFP_KERNEL);
1313	if (!ie) {
1314		ret = -ENOMEM;
1315		goto out;
1316	}
1317
1318	ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1319
1320	ieee80211_build_preq_ies(sdata, ie, num_bands * iebufsz,
1321				 &sched_scan_ies, req->ie,
1322				 req->ie_len, bands_used, rate_masks, &chandef,
1323				 flags);
1324
1325	ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1326	if (ret == 0) {
1327		rcu_assign_pointer(local->sched_scan_sdata, sdata);
1328		rcu_assign_pointer(local->sched_scan_req, req);
1329	}
1330
1331	kfree(ie);
1332
1333out:
1334	if (ret) {
1335		/* Clean in case of failure after HW restart or upon resume. */
1336		RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1337		RCU_INIT_POINTER(local->sched_scan_req, NULL);
1338	}
1339
1340	return ret;
1341}
1342
1343int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1344				       struct cfg80211_sched_scan_request *req)
1345{
1346	struct ieee80211_local *local = sdata->local;
1347	int ret;
1348
1349	mutex_lock(&local->mtx);
1350
1351	if (rcu_access_pointer(local->sched_scan_sdata)) {
1352		mutex_unlock(&local->mtx);
1353		return -EBUSY;
1354	}
1355
1356	ret = __ieee80211_request_sched_scan_start(sdata, req);
1357
1358	mutex_unlock(&local->mtx);
1359	return ret;
1360}
1361
1362int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1363{
1364	struct ieee80211_sub_if_data *sched_scan_sdata;
1365	int ret = -ENOENT;
1366
1367	mutex_lock(&local->mtx);
1368
1369	if (!local->ops->sched_scan_stop) {
1370		ret = -ENOTSUPP;
1371		goto out;
1372	}
1373
1374	/* We don't want to restart sched scan anymore. */
1375	RCU_INIT_POINTER(local->sched_scan_req, NULL);
1376
1377	sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1378						lockdep_is_held(&local->mtx));
1379	if (sched_scan_sdata) {
1380		ret = drv_sched_scan_stop(local, sched_scan_sdata);
1381		if (!ret)
1382			RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1383	}
1384out:
1385	mutex_unlock(&local->mtx);
1386
1387	return ret;
1388}
1389
1390void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1391{
1392	struct ieee80211_local *local = hw_to_local(hw);
1393
1394	trace_api_sched_scan_results(local);
1395
1396	cfg80211_sched_scan_results(hw->wiphy, 0);
1397}
1398EXPORT_SYMBOL(ieee80211_sched_scan_results);
1399
1400void ieee80211_sched_scan_end(struct ieee80211_local *local)
1401{
1402	mutex_lock(&local->mtx);
1403
1404	if (!rcu_access_pointer(local->sched_scan_sdata)) {
1405		mutex_unlock(&local->mtx);
1406		return;
1407	}
1408
1409	RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1410
1411	/* If sched scan was aborted by the driver. */
1412	RCU_INIT_POINTER(local->sched_scan_req, NULL);
1413
1414	mutex_unlock(&local->mtx);
1415
1416	cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1417}
1418
1419void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1420{
1421	struct ieee80211_local *local =
1422		container_of(work, struct ieee80211_local,
1423			     sched_scan_stopped_work);
1424
1425	ieee80211_sched_scan_end(local);
1426}
1427
1428void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1429{
1430	struct ieee80211_local *local = hw_to_local(hw);
1431
1432	trace_api_sched_scan_stopped(local);
1433
1434	/*
1435	 * this shouldn't really happen, so for simplicity
1436	 * simply ignore it, and let mac80211 reconfigure
1437	 * the sched scan later on.
1438	 */
1439	if (local->in_reconfig)
1440		return;
1441
1442	schedule_work(&local->sched_scan_stopped_work);
1443}
1444EXPORT_SYMBOL(ieee80211_sched_scan_stopped);
v4.17
 
   1/*
   2 * Scanning implementation
   3 *
   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
  11 *
  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.
  15 */
  16
  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 <net/mac80211.h>
  24
  25#include "ieee80211_i.h"
  26#include "driver-ops.h"
  27#include "mesh.h"
  28
  29#define IEEE80211_PROBE_DELAY (HZ / 33)
  30#define IEEE80211_CHANNEL_TIME (HZ / 33)
  31#define IEEE80211_PASSIVE_CHANNEL_TIME (HZ / 9)
  32
  33void ieee80211_rx_bss_put(struct ieee80211_local *local,
  34			  struct ieee80211_bss *bss)
  35{
  36	if (!bss)
  37		return;
  38	cfg80211_put_bss(local->hw.wiphy,
  39			 container_of((void *)bss, struct cfg80211_bss, priv));
  40}
  41
  42static bool is_uapsd_supported(struct ieee802_11_elems *elems)
  43{
  44	u8 qos_info;
  45
  46	if (elems->wmm_info && elems->wmm_info_len == 7
  47	    && elems->wmm_info[5] == 1)
  48		qos_info = elems->wmm_info[6];
  49	else if (elems->wmm_param && elems->wmm_param_len == 24
  50		 && elems->wmm_param[5] == 1)
  51		qos_info = elems->wmm_param[6];
  52	else
  53		/* no valid wmm information or parameter element found */
  54		return false;
  55
  56	return qos_info & IEEE80211_WMM_IE_AP_QOSINFO_UAPSD;
  57}
  58
  59struct ieee80211_bss *
  60ieee80211_bss_info_update(struct ieee80211_local *local,
  61			  struct ieee80211_rx_status *rx_status,
  62			  struct ieee80211_mgmt *mgmt, size_t len,
  63			  struct ieee802_11_elems *elems,
  64			  struct ieee80211_channel *channel)
  65{
  66	bool beacon = ieee80211_is_beacon(mgmt->frame_control);
  67	struct cfg80211_bss *cbss;
  68	struct ieee80211_bss *bss;
  69	int clen, srlen;
  70	struct cfg80211_inform_bss bss_meta = {
  71		.boottime_ns = rx_status->boottime_ns,
  72	};
  73	bool signal_valid;
  74	struct ieee80211_sub_if_data *scan_sdata;
  75
  76	if (rx_status->flag & RX_FLAG_NO_SIGNAL_VAL)
  77		bss_meta.signal = 0; /* invalid signal indication */
  78	else if (ieee80211_hw_check(&local->hw, SIGNAL_DBM))
  79		bss_meta.signal = rx_status->signal * 100;
  80	else if (ieee80211_hw_check(&local->hw, SIGNAL_UNSPEC))
  81		bss_meta.signal = (rx_status->signal * 100) / local->hw.max_signal;
  82
  83	bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_20;
  84	if (rx_status->bw == RATE_INFO_BW_5)
  85		bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_5;
  86	else if (rx_status->bw == RATE_INFO_BW_10)
  87		bss_meta.scan_width = NL80211_BSS_CHAN_WIDTH_10;
  88
  89	bss_meta.chan = channel;
  90
  91	rcu_read_lock();
  92	scan_sdata = rcu_dereference(local->scan_sdata);
  93	if (scan_sdata && scan_sdata->vif.type == NL80211_IFTYPE_STATION &&
  94	    scan_sdata->vif.bss_conf.assoc &&
  95	    ieee80211_have_rx_timestamp(rx_status)) {
  96		bss_meta.parent_tsf =
  97			ieee80211_calculate_rx_timestamp(local, rx_status,
  98							 len + FCS_LEN, 24);
  99		ether_addr_copy(bss_meta.parent_bssid,
 100				scan_sdata->vif.bss_conf.bssid);
 101	}
 102	rcu_read_unlock();
 103
 104	cbss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta,
 105					      mgmt, len, GFP_ATOMIC);
 106	if (!cbss)
 107		return NULL;
 108	/* In case the signal is invalid update the status */
 109	signal_valid = abs(channel->center_freq - cbss->channel->center_freq)
 110		<= local->hw.wiphy->max_adj_channel_rssi_comp;
 111	if (!signal_valid)
 112		rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
 113
 114	bss = (void *)cbss->priv;
 115
 116	if (beacon)
 117		bss->device_ts_beacon = rx_status->device_timestamp;
 118	else
 119		bss->device_ts_presp = rx_status->device_timestamp;
 120
 121	if (elems->parse_error) {
 122		if (beacon)
 123			bss->corrupt_data |= IEEE80211_BSS_CORRUPT_BEACON;
 124		else
 125			bss->corrupt_data |= IEEE80211_BSS_CORRUPT_PROBE_RESP;
 126	} else {
 127		if (beacon)
 128			bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_BEACON;
 129		else
 130			bss->corrupt_data &= ~IEEE80211_BSS_CORRUPT_PROBE_RESP;
 131	}
 132
 133	/* save the ERP value so that it is available at association time */
 134	if (elems->erp_info && (!elems->parse_error ||
 135				!(bss->valid_data & IEEE80211_BSS_VALID_ERP))) {
 136		bss->erp_value = elems->erp_info[0];
 137		bss->has_erp_value = true;
 138		if (!elems->parse_error)
 139			bss->valid_data |= IEEE80211_BSS_VALID_ERP;
 140	}
 141
 142	/* replace old supported rates if we get new values */
 143	if (!elems->parse_error ||
 144	    !(bss->valid_data & IEEE80211_BSS_VALID_RATES)) {
 145		srlen = 0;
 146		if (elems->supp_rates) {
 147			clen = IEEE80211_MAX_SUPP_RATES;
 148			if (clen > elems->supp_rates_len)
 149				clen = elems->supp_rates_len;
 150			memcpy(bss->supp_rates, elems->supp_rates, clen);
 151			srlen += clen;
 152		}
 153		if (elems->ext_supp_rates) {
 154			clen = IEEE80211_MAX_SUPP_RATES - srlen;
 155			if (clen > elems->ext_supp_rates_len)
 156				clen = elems->ext_supp_rates_len;
 157			memcpy(bss->supp_rates + srlen, elems->ext_supp_rates,
 158			       clen);
 159			srlen += clen;
 160		}
 161		if (srlen) {
 162			bss->supp_rates_len = srlen;
 163			if (!elems->parse_error)
 164				bss->valid_data |= IEEE80211_BSS_VALID_RATES;
 165		}
 166	}
 167
 168	if (!elems->parse_error ||
 169	    !(bss->valid_data & IEEE80211_BSS_VALID_WMM)) {
 170		bss->wmm_used = elems->wmm_param || elems->wmm_info;
 171		bss->uapsd_supported = is_uapsd_supported(elems);
 172		if (!elems->parse_error)
 173			bss->valid_data |= IEEE80211_BSS_VALID_WMM;
 174	}
 175
 176	if (beacon) {
 177		struct ieee80211_supported_band *sband =
 178			local->hw.wiphy->bands[rx_status->band];
 179		if (!(rx_status->encoding == RX_ENC_HT) &&
 180		    !(rx_status->encoding == RX_ENC_VHT))
 181			bss->beacon_rate =
 182				&sband->bitrates[rx_status->rate_idx];
 183	}
 184
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 185	return bss;
 186}
 187
 188static bool ieee80211_scan_accept_presp(struct ieee80211_sub_if_data *sdata,
 189					u32 scan_flags, const u8 *da)
 190{
 191	if (!sdata)
 192		return false;
 193	/* accept broadcast for OCE */
 194	if (scan_flags & NL80211_SCAN_FLAG_ACCEPT_BCAST_PROBE_RESP &&
 195	    is_broadcast_ether_addr(da))
 196		return true;
 197	if (scan_flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
 198		return true;
 199	return ether_addr_equal(da, sdata->vif.addr);
 200}
 201
 202void ieee80211_scan_rx(struct ieee80211_local *local, struct sk_buff *skb)
 203{
 204	struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
 205	struct ieee80211_sub_if_data *sdata1, *sdata2;
 206	struct ieee80211_mgmt *mgmt = (void *)skb->data;
 207	struct ieee80211_bss *bss;
 208	u8 *elements;
 209	struct ieee80211_channel *channel;
 210	size_t baselen;
 211	struct ieee802_11_elems elems;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 212
 213	if (skb->len < 24 ||
 214	    (!ieee80211_is_probe_resp(mgmt->frame_control) &&
 215	     !ieee80211_is_beacon(mgmt->frame_control)))
 216		return;
 217
 218	sdata1 = rcu_dereference(local->scan_sdata);
 219	sdata2 = rcu_dereference(local->sched_scan_sdata);
 220
 221	if (likely(!sdata1 && !sdata2))
 222		return;
 223
 224	if (ieee80211_is_probe_resp(mgmt->frame_control)) {
 225		struct cfg80211_scan_request *scan_req;
 226		struct cfg80211_sched_scan_request *sched_scan_req;
 227		u32 scan_req_flags = 0, sched_scan_req_flags = 0;
 228
 229		scan_req = rcu_dereference(local->scan_req);
 230		sched_scan_req = rcu_dereference(local->sched_scan_req);
 231
 232		if (scan_req)
 233			scan_req_flags = scan_req->flags;
 234
 235		if (sched_scan_req)
 236			sched_scan_req_flags = sched_scan_req->flags;
 237
 238		/* ignore ProbeResp to foreign address or non-bcast (OCE)
 239		 * unless scanning with randomised address
 240		 */
 241		if (!ieee80211_scan_accept_presp(sdata1, scan_req_flags,
 242						 mgmt->da) &&
 243		    !ieee80211_scan_accept_presp(sdata2, sched_scan_req_flags,
 244						 mgmt->da))
 245			return;
 246
 247		elements = mgmt->u.probe_resp.variable;
 248		baselen = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
 249	} else {
 250		baselen = offsetof(struct ieee80211_mgmt, u.beacon.variable);
 251		elements = mgmt->u.beacon.variable;
 252	}
 253
 254	if (baselen > skb->len)
 255		return;
 256
 257	ieee802_11_parse_elems(elements, skb->len - baselen, false, &elems);
 258
 259	channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
 260
 261	if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
 262		return;
 263
 264	bss = ieee80211_bss_info_update(local, rx_status,
 265					mgmt, skb->len, &elems,
 266					channel);
 267	if (bss)
 268		ieee80211_rx_bss_put(local, bss);
 269}
 270
 271static void
 272ieee80211_prepare_scan_chandef(struct cfg80211_chan_def *chandef,
 273			       enum nl80211_bss_scan_width scan_width)
 274{
 275	memset(chandef, 0, sizeof(*chandef));
 276	switch (scan_width) {
 277	case NL80211_BSS_CHAN_WIDTH_5:
 278		chandef->width = NL80211_CHAN_WIDTH_5;
 279		break;
 280	case NL80211_BSS_CHAN_WIDTH_10:
 281		chandef->width = NL80211_CHAN_WIDTH_10;
 282		break;
 283	default:
 284		chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
 285		break;
 286	}
 287}
 288
 289/* return false if no more work */
 290static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
 291{
 
 292	struct cfg80211_scan_request *req;
 293	struct cfg80211_chan_def chandef;
 294	u8 bands_used = 0;
 295	int i, ielen, n_chans;
 
 296
 297	req = rcu_dereference_protected(local->scan_req,
 298					lockdep_is_held(&local->mtx));
 299
 300	if (test_bit(SCAN_HW_CANCELLED, &local->scanning))
 301		return false;
 302
 303	if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
 304		for (i = 0; i < req->n_channels; i++) {
 305			local->hw_scan_req->req.channels[i] = req->channels[i];
 306			bands_used |= BIT(req->channels[i]->band);
 307		}
 308
 309		n_chans = req->n_channels;
 310	} else {
 311		do {
 312			if (local->hw_scan_band == NUM_NL80211_BANDS)
 313				return false;
 314
 315			n_chans = 0;
 316
 317			for (i = 0; i < req->n_channels; i++) {
 318				if (req->channels[i]->band !=
 319				    local->hw_scan_band)
 320					continue;
 321				local->hw_scan_req->req.channels[n_chans] =
 322							req->channels[i];
 323				n_chans++;
 324				bands_used |= BIT(req->channels[i]->band);
 325			}
 326
 327			local->hw_scan_band++;
 328		} while (!n_chans);
 329	}
 330
 331	local->hw_scan_req->req.n_channels = n_chans;
 332	ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
 333
 334	ielen = ieee80211_build_preq_ies(local,
 
 
 
 335					 (u8 *)local->hw_scan_req->req.ie,
 336					 local->hw_scan_ies_bufsize,
 337					 &local->hw_scan_req->ies,
 338					 req->ie, req->ie_len,
 339					 bands_used, req->rates, &chandef);
 
 340	local->hw_scan_req->req.ie_len = ielen;
 341	local->hw_scan_req->req.no_cck = req->no_cck;
 342	ether_addr_copy(local->hw_scan_req->req.mac_addr, req->mac_addr);
 343	ether_addr_copy(local->hw_scan_req->req.mac_addr_mask,
 344			req->mac_addr_mask);
 345	ether_addr_copy(local->hw_scan_req->req.bssid, req->bssid);
 346
 347	return true;
 348}
 349
 350static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
 351{
 352	struct ieee80211_local *local = hw_to_local(hw);
 353	bool hw_scan = local->ops->hw_scan;
 354	bool was_scanning = local->scanning;
 355	struct cfg80211_scan_request *scan_req;
 356	struct ieee80211_sub_if_data *scan_sdata;
 357	struct ieee80211_sub_if_data *sdata;
 358
 359	lockdep_assert_held(&local->mtx);
 360
 361	/*
 362	 * It's ok to abort a not-yet-running scan (that
 363	 * we have one at all will be verified by checking
 364	 * local->scan_req next), but not to complete it
 365	 * successfully.
 366	 */
 367	if (WARN_ON(!local->scanning && !aborted))
 368		aborted = true;
 369
 370	if (WARN_ON(!local->scan_req))
 371		return;
 372
 
 
 
 373	if (hw_scan && !aborted &&
 374	    !ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS) &&
 375	    ieee80211_prep_hw_scan(local)) {
 376		int rc;
 377
 378		rc = drv_hw_scan(local,
 379			rcu_dereference_protected(local->scan_sdata,
 380						  lockdep_is_held(&local->mtx)),
 381			local->hw_scan_req);
 382
 383		if (rc == 0)
 384			return;
 385
 386		/* HW scan failed and is going to be reported as aborted,
 387		 * so clear old scan info.
 388		 */
 389		memset(&local->scan_info, 0, sizeof(local->scan_info));
 390		aborted = true;
 391	}
 392
 393	kfree(local->hw_scan_req);
 394	local->hw_scan_req = NULL;
 395
 396	scan_req = rcu_dereference_protected(local->scan_req,
 397					     lockdep_is_held(&local->mtx));
 398
 399	if (scan_req != local->int_scan_req) {
 400		local->scan_info.aborted = aborted;
 401		cfg80211_scan_done(scan_req, &local->scan_info);
 402	}
 403	RCU_INIT_POINTER(local->scan_req, NULL);
 404
 405	scan_sdata = rcu_dereference_protected(local->scan_sdata,
 406					       lockdep_is_held(&local->mtx));
 407	RCU_INIT_POINTER(local->scan_sdata, NULL);
 408
 409	local->scanning = 0;
 410	local->scan_chandef.chan = NULL;
 411
 412	/* Set power back to normal operating levels. */
 413	ieee80211_hw_config(local, 0);
 414
 415	if (!hw_scan) {
 416		ieee80211_configure_filter(local);
 417		drv_sw_scan_complete(local, scan_sdata);
 418		ieee80211_offchannel_return(local);
 419	}
 420
 421	ieee80211_recalc_idle(local);
 422
 423	ieee80211_mlme_notify_scan_completed(local);
 424	ieee80211_ibss_notify_scan_completed(local);
 425
 426	/* Requeue all the work that might have been ignored while
 427	 * the scan was in progress; if there was none this will
 428	 * just be a no-op for the particular interface.
 429	 */
 430	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 431		if (ieee80211_sdata_running(sdata))
 432			ieee80211_queue_work(&sdata->local->hw, &sdata->work);
 433	}
 434
 435	if (was_scanning)
 436		ieee80211_start_next_roc(local);
 437}
 438
 439void ieee80211_scan_completed(struct ieee80211_hw *hw,
 440			      struct cfg80211_scan_info *info)
 441{
 442	struct ieee80211_local *local = hw_to_local(hw);
 443
 444	trace_api_scan_completed(local, info->aborted);
 445
 446	set_bit(SCAN_COMPLETED, &local->scanning);
 447	if (info->aborted)
 448		set_bit(SCAN_ABORTED, &local->scanning);
 449
 450	memcpy(&local->scan_info, info, sizeof(*info));
 451
 452	ieee80211_queue_delayed_work(&local->hw, &local->scan_work, 0);
 453}
 454EXPORT_SYMBOL(ieee80211_scan_completed);
 455
 456static int ieee80211_start_sw_scan(struct ieee80211_local *local,
 457				   struct ieee80211_sub_if_data *sdata)
 458{
 459	/* Software scan is not supported in multi-channel cases */
 460	if (local->use_chanctx)
 461		return -EOPNOTSUPP;
 462
 463	/*
 464	 * Hardware/driver doesn't support hw_scan, so use software
 465	 * scanning instead. First send a nullfunc frame with power save
 466	 * bit on so that AP will buffer the frames for us while we are not
 467	 * listening, then send probe requests to each channel and wait for
 468	 * the responses. After all channels are scanned, tune back to the
 469	 * original channel and send a nullfunc frame with power save bit
 470	 * off to trigger the AP to send us all the buffered frames.
 471	 *
 472	 * Note that while local->sw_scanning is true everything else but
 473	 * nullfunc frames and probe requests will be dropped in
 474	 * ieee80211_tx_h_check_assoc().
 475	 */
 476	drv_sw_scan_start(local, sdata, local->scan_addr);
 477
 478	local->leave_oper_channel_time = jiffies;
 479	local->next_scan_state = SCAN_DECISION;
 480	local->scan_channel_idx = 0;
 481
 482	ieee80211_offchannel_stop_vifs(local);
 483
 484	/* ensure nullfunc is transmitted before leaving operating channel */
 485	ieee80211_flush_queues(local, NULL, false);
 486
 487	ieee80211_configure_filter(local);
 488
 489	/* We need to set power level at maximum rate for scanning. */
 490	ieee80211_hw_config(local, 0);
 491
 492	ieee80211_queue_delayed_work(&local->hw,
 493				     &local->scan_work, 0);
 494
 495	return 0;
 496}
 497
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 498static bool ieee80211_can_scan(struct ieee80211_local *local,
 499			       struct ieee80211_sub_if_data *sdata)
 500{
 501	if (ieee80211_is_radar_required(local))
 502		return false;
 503
 504	if (!list_empty(&local->roc_list))
 505		return false;
 506
 507	if (sdata->vif.type == NL80211_IFTYPE_STATION &&
 508	    sdata->u.mgd.flags & IEEE80211_STA_CONNECTION_POLL)
 509		return false;
 510
 511	return true;
 512}
 513
 514void ieee80211_run_deferred_scan(struct ieee80211_local *local)
 515{
 516	lockdep_assert_held(&local->mtx);
 517
 518	if (!local->scan_req || local->scanning)
 519		return;
 520
 521	if (!ieee80211_can_scan(local,
 522				rcu_dereference_protected(
 523					local->scan_sdata,
 524					lockdep_is_held(&local->mtx))))
 525		return;
 526
 527	ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
 528				     round_jiffies_relative(0));
 529}
 530
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 531static void ieee80211_scan_state_send_probe(struct ieee80211_local *local,
 532					    unsigned long *next_delay)
 533{
 534	int i;
 535	struct ieee80211_sub_if_data *sdata;
 536	struct cfg80211_scan_request *scan_req;
 537	enum nl80211_band band = local->hw.conf.chandef.chan->band;
 538	u32 tx_flags;
 539
 540	scan_req = rcu_dereference_protected(local->scan_req,
 541					     lockdep_is_held(&local->mtx));
 542
 543	tx_flags = IEEE80211_TX_INTFL_OFFCHAN_TX_OK;
 544	if (scan_req->no_cck)
 545		tx_flags |= IEEE80211_TX_CTL_NO_CCK_RATE;
 
 
 
 
 546
 547	sdata = rcu_dereference_protected(local->scan_sdata,
 548					  lockdep_is_held(&local->mtx));
 549
 550	for (i = 0; i < scan_req->n_ssids; i++)
 551		ieee80211_send_probe_req(
 552			sdata, local->scan_addr, scan_req->bssid,
 553			scan_req->ssids[i].ssid, scan_req->ssids[i].ssid_len,
 554			scan_req->ie, scan_req->ie_len,
 555			scan_req->rates[band], false,
 556			tx_flags, local->hw.conf.chandef.chan, true);
 557
 558	/*
 559	 * After sending probe requests, wait for probe responses
 560	 * on the channel.
 561	 */
 562	*next_delay = IEEE80211_CHANNEL_TIME;
 563	local->next_scan_state = SCAN_DECISION;
 564}
 565
 566static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata,
 567				  struct cfg80211_scan_request *req)
 568{
 569	struct ieee80211_local *local = sdata->local;
 
 570	int rc;
 571
 572	lockdep_assert_held(&local->mtx);
 573
 574	if (local->scan_req || ieee80211_is_radar_required(local))
 
 
 
 575		return -EBUSY;
 576
 577	if (!ieee80211_can_scan(local, sdata)) {
 578		/* wait for the work to finish/time out */
 579		rcu_assign_pointer(local->scan_req, req);
 580		rcu_assign_pointer(local->scan_sdata, sdata);
 581		return 0;
 582	}
 583
 584	if (local->ops->hw_scan) {
 
 585		u8 *ies;
 586
 587		local->hw_scan_ies_bufsize = local->scan_ies_len + req->ie_len;
 588
 589		if (ieee80211_hw_check(&local->hw, SINGLE_SCAN_ON_ALL_BANDS)) {
 590			int i, n_bands = 0;
 591			u8 bands_counted = 0;
 592
 593			for (i = 0; i < req->n_channels; i++) {
 594				if (bands_counted & BIT(req->channels[i]->band))
 595					continue;
 596				bands_counted |= BIT(req->channels[i]->band);
 597				n_bands++;
 598			}
 599
 600			local->hw_scan_ies_bufsize *= n_bands;
 601		}
 602
 603		local->hw_scan_req = kmalloc(
 604				sizeof(*local->hw_scan_req) +
 605				req->n_channels * sizeof(req->channels[0]) +
 606				local->hw_scan_ies_bufsize, GFP_KERNEL);
 607		if (!local->hw_scan_req)
 608			return -ENOMEM;
 609
 610		local->hw_scan_req->req.ssids = req->ssids;
 611		local->hw_scan_req->req.n_ssids = req->n_ssids;
 612		ies = (u8 *)local->hw_scan_req +
 613			sizeof(*local->hw_scan_req) +
 614			req->n_channels * sizeof(req->channels[0]);
 615		local->hw_scan_req->req.ie = ies;
 616		local->hw_scan_req->req.flags = req->flags;
 617		eth_broadcast_addr(local->hw_scan_req->req.bssid);
 618		local->hw_scan_req->req.duration = req->duration;
 619		local->hw_scan_req->req.duration_mandatory =
 620			req->duration_mandatory;
 621
 622		local->hw_scan_band = 0;
 
 
 
 
 623
 624		/*
 625		 * After allocating local->hw_scan_req, we must
 626		 * go through until ieee80211_prep_hw_scan(), so
 627		 * anything that might be changed here and leave
 628		 * this function early must not go after this
 629		 * allocation.
 630		 */
 631	}
 632
 633	rcu_assign_pointer(local->scan_req, req);
 634	rcu_assign_pointer(local->scan_sdata, sdata);
 635
 636	if (req->flags & NL80211_SCAN_FLAG_RANDOM_ADDR)
 637		get_random_mask_addr(local->scan_addr,
 638				     req->mac_addr,
 639				     req->mac_addr_mask);
 640	else
 641		memcpy(local->scan_addr, sdata->vif.addr, ETH_ALEN);
 642
 643	if (local->ops->hw_scan) {
 644		__set_bit(SCAN_HW_SCANNING, &local->scanning);
 645	} else if ((req->n_channels == 1) &&
 646		   (req->channels[0] == local->_oper_chandef.chan)) {
 647		/*
 648		 * If we are scanning only on the operating channel
 649		 * then we do not need to stop normal activities
 650		 */
 651		unsigned long next_delay;
 652
 653		__set_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning);
 654
 655		ieee80211_recalc_idle(local);
 656
 657		/* Notify driver scan is starting, keep order of operations
 658		 * same as normal software scan, in case that matters. */
 659		drv_sw_scan_start(local, sdata, local->scan_addr);
 660
 661		ieee80211_configure_filter(local); /* accept probe-responses */
 662
 663		/* We need to ensure power level is at max for scanning. */
 664		ieee80211_hw_config(local, 0);
 665
 666		if ((req->channels[0]->flags & (IEEE80211_CHAN_NO_IR |
 667						IEEE80211_CHAN_RADAR)) ||
 668		    !req->n_ssids) {
 669			next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
 670		} else {
 671			ieee80211_scan_state_send_probe(local, &next_delay);
 672			next_delay = IEEE80211_CHANNEL_TIME;
 673		}
 674
 675		/* Now, just wait a bit and we are all done! */
 676		ieee80211_queue_delayed_work(&local->hw, &local->scan_work,
 677					     next_delay);
 678		return 0;
 679	} else {
 680		/* Do normal software scan */
 681		__set_bit(SCAN_SW_SCANNING, &local->scanning);
 682	}
 683
 684	ieee80211_recalc_idle(local);
 685
 686	if (local->ops->hw_scan) {
 687		WARN_ON(!ieee80211_prep_hw_scan(local));
 688		rc = drv_hw_scan(local, sdata, local->hw_scan_req);
 689	} else {
 690		rc = ieee80211_start_sw_scan(local, sdata);
 691	}
 692
 693	if (rc) {
 694		kfree(local->hw_scan_req);
 695		local->hw_scan_req = NULL;
 696		local->scanning = 0;
 697
 698		ieee80211_recalc_idle(local);
 699
 700		local->scan_req = NULL;
 701		RCU_INIT_POINTER(local->scan_sdata, NULL);
 702	}
 703
 
 
 
 
 
 
 
 
 
 
 
 
 704	return rc;
 705}
 706
 707static unsigned long
 708ieee80211_scan_get_channel_time(struct ieee80211_channel *chan)
 709{
 710	/*
 711	 * TODO: channel switching also consumes quite some time,
 712	 * add that delay as well to get a better estimation
 713	 */
 714	if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR))
 715		return IEEE80211_PASSIVE_CHANNEL_TIME;
 716	return IEEE80211_PROBE_DELAY + IEEE80211_CHANNEL_TIME;
 717}
 718
 719static void ieee80211_scan_state_decision(struct ieee80211_local *local,
 720					  unsigned long *next_delay)
 721{
 722	bool associated = false;
 723	bool tx_empty = true;
 724	bool bad_latency;
 725	struct ieee80211_sub_if_data *sdata;
 726	struct ieee80211_channel *next_chan;
 727	enum mac80211_scan_state next_scan_state;
 728	struct cfg80211_scan_request *scan_req;
 729
 730	/*
 731	 * check if at least one STA interface is associated,
 732	 * check if at least one STA interface has pending tx frames
 733	 * and grab the lowest used beacon interval
 734	 */
 735	mutex_lock(&local->iflist_mtx);
 736	list_for_each_entry(sdata, &local->interfaces, list) {
 737		if (!ieee80211_sdata_running(sdata))
 738			continue;
 739
 740		if (sdata->vif.type == NL80211_IFTYPE_STATION) {
 741			if (sdata->u.mgd.associated) {
 742				associated = true;
 743
 744				if (!qdisc_all_tx_empty(sdata->dev)) {
 745					tx_empty = false;
 746					break;
 747				}
 748			}
 749		}
 750	}
 751	mutex_unlock(&local->iflist_mtx);
 752
 753	scan_req = rcu_dereference_protected(local->scan_req,
 754					     lockdep_is_held(&local->mtx));
 755
 756	next_chan = scan_req->channels[local->scan_channel_idx];
 757
 758	/*
 759	 * we're currently scanning a different channel, let's
 760	 * see if we can scan another channel without interfering
 761	 * with the current traffic situation.
 762	 *
 763	 * Keep good latency, do not stay off-channel more than 125 ms.
 764	 */
 765
 766	bad_latency = time_after(jiffies +
 767				 ieee80211_scan_get_channel_time(next_chan),
 768				 local->leave_oper_channel_time + HZ / 8);
 769
 770	if (associated && !tx_empty) {
 771		if (scan_req->flags & NL80211_SCAN_FLAG_LOW_PRIORITY)
 772			next_scan_state = SCAN_ABORT;
 773		else
 774			next_scan_state = SCAN_SUSPEND;
 775	} else if (associated && bad_latency) {
 776		next_scan_state = SCAN_SUSPEND;
 777	} else {
 778		next_scan_state = SCAN_SET_CHANNEL;
 779	}
 780
 781	local->next_scan_state = next_scan_state;
 782
 783	*next_delay = 0;
 784}
 785
 786static void ieee80211_scan_state_set_channel(struct ieee80211_local *local,
 787					     unsigned long *next_delay)
 788{
 789	int skip;
 790	struct ieee80211_channel *chan;
 791	enum nl80211_bss_scan_width oper_scan_width;
 792	struct cfg80211_scan_request *scan_req;
 793
 794	scan_req = rcu_dereference_protected(local->scan_req,
 795					     lockdep_is_held(&local->mtx));
 796
 797	skip = 0;
 798	chan = scan_req->channels[local->scan_channel_idx];
 799
 800	local->scan_chandef.chan = chan;
 801	local->scan_chandef.center_freq1 = chan->center_freq;
 
 802	local->scan_chandef.center_freq2 = 0;
 
 
 
 
 
 
 
 
 
 
 
 803	switch (scan_req->scan_width) {
 804	case NL80211_BSS_CHAN_WIDTH_5:
 805		local->scan_chandef.width = NL80211_CHAN_WIDTH_5;
 806		break;
 807	case NL80211_BSS_CHAN_WIDTH_10:
 808		local->scan_chandef.width = NL80211_CHAN_WIDTH_10;
 809		break;
 
 810	case NL80211_BSS_CHAN_WIDTH_20:
 811		/* If scanning on oper channel, use whatever channel-type
 812		 * is currently in use.
 813		 */
 814		oper_scan_width = cfg80211_chandef_to_scan_width(
 815					&local->_oper_chandef);
 816		if (chan == local->_oper_chandef.chan &&
 817		    oper_scan_width == scan_req->scan_width)
 818			local->scan_chandef = local->_oper_chandef;
 819		else
 820			local->scan_chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
 821		break;
 
 
 
 
 
 822	}
 823
 
 824	if (ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL))
 825		skip = 1;
 826
 827	/* advance state machine to next channel/band */
 828	local->scan_channel_idx++;
 829
 830	if (skip) {
 831		/* if we skip this channel return to the decision state */
 832		local->next_scan_state = SCAN_DECISION;
 833		return;
 834	}
 835
 836	/*
 837	 * Probe delay is used to update the NAV, cf. 11.1.3.2.2
 838	 * (which unfortunately doesn't say _why_ step a) is done,
 839	 * but it waits for the probe delay or until a frame is
 840	 * received - and the received frame would update the NAV).
 841	 * For now, we do not support waiting until a frame is
 842	 * received.
 843	 *
 844	 * In any case, it is not necessary for a passive scan.
 845	 */
 846	if ((chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_RADAR)) ||
 847	    !scan_req->n_ssids) {
 848		*next_delay = IEEE80211_PASSIVE_CHANNEL_TIME;
 849		local->next_scan_state = SCAN_DECISION;
 850		return;
 851	}
 852
 853	/* active scan, send probes */
 854	*next_delay = IEEE80211_PROBE_DELAY;
 855	local->next_scan_state = SCAN_SEND_PROBE;
 856}
 857
 858static void ieee80211_scan_state_suspend(struct ieee80211_local *local,
 859					 unsigned long *next_delay)
 860{
 861	/* switch back to the operating channel */
 862	local->scan_chandef.chan = NULL;
 863	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 864
 865	/* disable PS */
 866	ieee80211_offchannel_return(local);
 867
 868	*next_delay = HZ / 5;
 869	/* afterwards, resume scan & go to next channel */
 870	local->next_scan_state = SCAN_RESUME;
 871}
 872
 873static void ieee80211_scan_state_resume(struct ieee80211_local *local,
 874					unsigned long *next_delay)
 875{
 876	ieee80211_offchannel_stop_vifs(local);
 877
 878	if (local->ops->flush) {
 879		ieee80211_flush_queues(local, NULL, false);
 880		*next_delay = 0;
 881	} else
 882		*next_delay = HZ / 10;
 883
 884	/* remember when we left the operating channel */
 885	local->leave_oper_channel_time = jiffies;
 886
 887	/* advance to the next channel to be scanned */
 888	local->next_scan_state = SCAN_SET_CHANNEL;
 889}
 890
 891void ieee80211_scan_work(struct work_struct *work)
 892{
 893	struct ieee80211_local *local =
 894		container_of(work, struct ieee80211_local, scan_work.work);
 895	struct ieee80211_sub_if_data *sdata;
 896	struct cfg80211_scan_request *scan_req;
 897	unsigned long next_delay = 0;
 898	bool aborted;
 899
 900	mutex_lock(&local->mtx);
 901
 902	if (!ieee80211_can_run_worker(local)) {
 903		aborted = true;
 904		goto out_complete;
 905	}
 906
 907	sdata = rcu_dereference_protected(local->scan_sdata,
 908					  lockdep_is_held(&local->mtx));
 909	scan_req = rcu_dereference_protected(local->scan_req,
 910					     lockdep_is_held(&local->mtx));
 911
 912	/* When scanning on-channel, the first-callback means completed. */
 913	if (test_bit(SCAN_ONCHANNEL_SCANNING, &local->scanning)) {
 914		aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
 915		goto out_complete;
 916	}
 917
 918	if (test_and_clear_bit(SCAN_COMPLETED, &local->scanning)) {
 919		aborted = test_and_clear_bit(SCAN_ABORTED, &local->scanning);
 920		goto out_complete;
 921	}
 922
 923	if (!sdata || !scan_req)
 924		goto out;
 925
 926	if (!local->scanning) {
 927		int rc;
 928
 929		RCU_INIT_POINTER(local->scan_req, NULL);
 930		RCU_INIT_POINTER(local->scan_sdata, NULL);
 931
 932		rc = __ieee80211_start_scan(sdata, scan_req);
 933		if (rc) {
 934			/* need to complete scan in cfg80211 */
 935			rcu_assign_pointer(local->scan_req, scan_req);
 936			aborted = true;
 937			goto out_complete;
 938		} else
 939			goto out;
 940	}
 941
 942	/*
 943	 * as long as no delay is required advance immediately
 944	 * without scheduling a new work
 945	 */
 946	do {
 947		if (!ieee80211_sdata_running(sdata)) {
 948			aborted = true;
 949			goto out_complete;
 950		}
 951
 952		switch (local->next_scan_state) {
 953		case SCAN_DECISION:
 954			/* if no more bands/channels left, complete scan */
 955			if (local->scan_channel_idx >= scan_req->n_channels) {
 956				aborted = false;
 957				goto out_complete;
 958			}
 959			ieee80211_scan_state_decision(local, &next_delay);
 960			break;
 961		case SCAN_SET_CHANNEL:
 962			ieee80211_scan_state_set_channel(local, &next_delay);
 963			break;
 964		case SCAN_SEND_PROBE:
 965			ieee80211_scan_state_send_probe(local, &next_delay);
 966			break;
 967		case SCAN_SUSPEND:
 968			ieee80211_scan_state_suspend(local, &next_delay);
 969			break;
 970		case SCAN_RESUME:
 971			ieee80211_scan_state_resume(local, &next_delay);
 972			break;
 973		case SCAN_ABORT:
 974			aborted = true;
 975			goto out_complete;
 976		}
 977	} while (next_delay == 0);
 978
 979	ieee80211_queue_delayed_work(&local->hw, &local->scan_work, next_delay);
 980	goto out;
 981
 982out_complete:
 983	__ieee80211_scan_completed(&local->hw, aborted);
 984out:
 985	mutex_unlock(&local->mtx);
 986}
 987
 988int ieee80211_request_scan(struct ieee80211_sub_if_data *sdata,
 989			   struct cfg80211_scan_request *req)
 990{
 991	int res;
 992
 993	mutex_lock(&sdata->local->mtx);
 994	res = __ieee80211_start_scan(sdata, req);
 995	mutex_unlock(&sdata->local->mtx);
 996
 997	return res;
 998}
 999
1000int ieee80211_request_ibss_scan(struct ieee80211_sub_if_data *sdata,
1001				const u8 *ssid, u8 ssid_len,
1002				struct ieee80211_channel **channels,
1003				unsigned int n_channels,
1004				enum nl80211_bss_scan_width scan_width)
1005{
1006	struct ieee80211_local *local = sdata->local;
1007	int ret = -EBUSY, i, n_ch = 0;
1008	enum nl80211_band band;
1009
1010	mutex_lock(&local->mtx);
1011
1012	/* busy scanning */
1013	if (local->scan_req)
1014		goto unlock;
1015
1016	/* fill internal scan request */
1017	if (!channels) {
1018		int max_n;
1019
1020		for (band = 0; band < NUM_NL80211_BANDS; band++) {
1021			if (!local->hw.wiphy->bands[band])
 
1022				continue;
1023
1024			max_n = local->hw.wiphy->bands[band]->n_channels;
1025			for (i = 0; i < max_n; i++) {
1026				struct ieee80211_channel *tmp_ch =
1027				    &local->hw.wiphy->bands[band]->channels[i];
1028
1029				if (tmp_ch->flags & (IEEE80211_CHAN_NO_IR |
1030						     IEEE80211_CHAN_DISABLED))
1031					continue;
1032
1033				local->int_scan_req->channels[n_ch] = tmp_ch;
1034				n_ch++;
1035			}
1036		}
1037
1038		if (WARN_ON_ONCE(n_ch == 0))
1039			goto unlock;
1040
1041		local->int_scan_req->n_channels = n_ch;
1042	} else {
1043		for (i = 0; i < n_channels; i++) {
1044			if (channels[i]->flags & (IEEE80211_CHAN_NO_IR |
1045						  IEEE80211_CHAN_DISABLED))
1046				continue;
1047
1048			local->int_scan_req->channels[n_ch] = channels[i];
1049			n_ch++;
1050		}
1051
1052		if (WARN_ON_ONCE(n_ch == 0))
1053			goto unlock;
1054
1055		local->int_scan_req->n_channels = n_ch;
1056	}
1057
1058	local->int_scan_req->ssids = &local->scan_ssid;
1059	local->int_scan_req->n_ssids = 1;
1060	local->int_scan_req->scan_width = scan_width;
1061	memcpy(local->int_scan_req->ssids[0].ssid, ssid, IEEE80211_MAX_SSID_LEN);
1062	local->int_scan_req->ssids[0].ssid_len = ssid_len;
1063
1064	ret = __ieee80211_start_scan(sdata, sdata->local->int_scan_req);
1065 unlock:
1066	mutex_unlock(&local->mtx);
1067	return ret;
1068}
1069
1070/*
1071 * Only call this function when a scan can't be queued -- under RTNL.
1072 */
1073void ieee80211_scan_cancel(struct ieee80211_local *local)
1074{
1075	/*
1076	 * We are canceling software scan, or deferred scan that was not
1077	 * yet really started (see __ieee80211_start_scan ).
1078	 *
1079	 * Regarding hardware scan:
1080	 * - we can not call  __ieee80211_scan_completed() as when
1081	 *   SCAN_HW_SCANNING bit is set this function change
1082	 *   local->hw_scan_req to operate on 5G band, what race with
1083	 *   driver which can use local->hw_scan_req
1084	 *
1085	 * - we can not cancel scan_work since driver can schedule it
1086	 *   by ieee80211_scan_completed(..., true) to finish scan
1087	 *
1088	 * Hence we only call the cancel_hw_scan() callback, but the low-level
1089	 * driver is still responsible for calling ieee80211_scan_completed()
1090	 * after the scan was completed/aborted.
1091	 */
1092
1093	mutex_lock(&local->mtx);
1094	if (!local->scan_req)
1095		goto out;
1096
1097	/*
1098	 * We have a scan running and the driver already reported completion,
1099	 * but the worker hasn't run yet or is stuck on the mutex - mark it as
1100	 * cancelled.
1101	 */
1102	if (test_bit(SCAN_HW_SCANNING, &local->scanning) &&
1103	    test_bit(SCAN_COMPLETED, &local->scanning)) {
1104		set_bit(SCAN_HW_CANCELLED, &local->scanning);
1105		goto out;
1106	}
1107
1108	if (test_bit(SCAN_HW_SCANNING, &local->scanning)) {
1109		/*
1110		 * Make sure that __ieee80211_scan_completed doesn't trigger a
1111		 * scan on another band.
1112		 */
1113		set_bit(SCAN_HW_CANCELLED, &local->scanning);
1114		if (local->ops->cancel_hw_scan)
1115			drv_cancel_hw_scan(local,
1116				rcu_dereference_protected(local->scan_sdata,
1117						lockdep_is_held(&local->mtx)));
1118		goto out;
1119	}
1120
1121	/*
1122	 * If the work is currently running, it must be blocked on
1123	 * the mutex, but we'll set scan_sdata = NULL and it'll
1124	 * simply exit once it acquires the mutex.
1125	 */
1126	cancel_delayed_work(&local->scan_work);
1127	/* and clean up */
1128	memset(&local->scan_info, 0, sizeof(local->scan_info));
1129	__ieee80211_scan_completed(&local->hw, true);
1130out:
1131	mutex_unlock(&local->mtx);
1132}
1133
1134int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1135					struct cfg80211_sched_scan_request *req)
1136{
1137	struct ieee80211_local *local = sdata->local;
1138	struct ieee80211_scan_ies sched_scan_ies = {};
1139	struct cfg80211_chan_def chandef;
1140	int ret, i, iebufsz, num_bands = 0;
1141	u32 rate_masks[NUM_NL80211_BANDS] = {};
1142	u8 bands_used = 0;
1143	u8 *ie;
 
1144
1145	iebufsz = local->scan_ies_len + req->ie_len;
1146
1147	lockdep_assert_held(&local->mtx);
1148
1149	if (!local->ops->sched_scan_start)
1150		return -ENOTSUPP;
1151
1152	for (i = 0; i < NUM_NL80211_BANDS; i++) {
1153		if (local->hw.wiphy->bands[i]) {
1154			bands_used |= BIT(i);
1155			rate_masks[i] = (u32) -1;
1156			num_bands++;
1157		}
1158	}
1159
1160	ie = kzalloc(num_bands * iebufsz, GFP_KERNEL);
 
 
 
1161	if (!ie) {
1162		ret = -ENOMEM;
1163		goto out;
1164	}
1165
1166	ieee80211_prepare_scan_chandef(&chandef, req->scan_width);
1167
1168	ieee80211_build_preq_ies(local, ie, num_bands * iebufsz,
1169				 &sched_scan_ies, req->ie,
1170				 req->ie_len, bands_used, rate_masks, &chandef);
 
1171
1172	ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
1173	if (ret == 0) {
1174		rcu_assign_pointer(local->sched_scan_sdata, sdata);
1175		rcu_assign_pointer(local->sched_scan_req, req);
1176	}
1177
1178	kfree(ie);
1179
1180out:
1181	if (ret) {
1182		/* Clean in case of failure after HW restart or upon resume. */
1183		RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1184		RCU_INIT_POINTER(local->sched_scan_req, NULL);
1185	}
1186
1187	return ret;
1188}
1189
1190int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
1191				       struct cfg80211_sched_scan_request *req)
1192{
1193	struct ieee80211_local *local = sdata->local;
1194	int ret;
1195
1196	mutex_lock(&local->mtx);
1197
1198	if (rcu_access_pointer(local->sched_scan_sdata)) {
1199		mutex_unlock(&local->mtx);
1200		return -EBUSY;
1201	}
1202
1203	ret = __ieee80211_request_sched_scan_start(sdata, req);
1204
1205	mutex_unlock(&local->mtx);
1206	return ret;
1207}
1208
1209int ieee80211_request_sched_scan_stop(struct ieee80211_local *local)
1210{
1211	struct ieee80211_sub_if_data *sched_scan_sdata;
1212	int ret = -ENOENT;
1213
1214	mutex_lock(&local->mtx);
1215
1216	if (!local->ops->sched_scan_stop) {
1217		ret = -ENOTSUPP;
1218		goto out;
1219	}
1220
1221	/* We don't want to restart sched scan anymore. */
1222	RCU_INIT_POINTER(local->sched_scan_req, NULL);
1223
1224	sched_scan_sdata = rcu_dereference_protected(local->sched_scan_sdata,
1225						lockdep_is_held(&local->mtx));
1226	if (sched_scan_sdata) {
1227		ret = drv_sched_scan_stop(local, sched_scan_sdata);
1228		if (!ret)
1229			RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1230	}
1231out:
1232	mutex_unlock(&local->mtx);
1233
1234	return ret;
1235}
1236
1237void ieee80211_sched_scan_results(struct ieee80211_hw *hw)
1238{
1239	struct ieee80211_local *local = hw_to_local(hw);
1240
1241	trace_api_sched_scan_results(local);
1242
1243	cfg80211_sched_scan_results(hw->wiphy, 0);
1244}
1245EXPORT_SYMBOL(ieee80211_sched_scan_results);
1246
1247void ieee80211_sched_scan_end(struct ieee80211_local *local)
1248{
1249	mutex_lock(&local->mtx);
1250
1251	if (!rcu_access_pointer(local->sched_scan_sdata)) {
1252		mutex_unlock(&local->mtx);
1253		return;
1254	}
1255
1256	RCU_INIT_POINTER(local->sched_scan_sdata, NULL);
1257
1258	/* If sched scan was aborted by the driver. */
1259	RCU_INIT_POINTER(local->sched_scan_req, NULL);
1260
1261	mutex_unlock(&local->mtx);
1262
1263	cfg80211_sched_scan_stopped(local->hw.wiphy, 0);
1264}
1265
1266void ieee80211_sched_scan_stopped_work(struct work_struct *work)
1267{
1268	struct ieee80211_local *local =
1269		container_of(work, struct ieee80211_local,
1270			     sched_scan_stopped_work);
1271
1272	ieee80211_sched_scan_end(local);
1273}
1274
1275void ieee80211_sched_scan_stopped(struct ieee80211_hw *hw)
1276{
1277	struct ieee80211_local *local = hw_to_local(hw);
1278
1279	trace_api_sched_scan_stopped(local);
1280
1281	/*
1282	 * this shouldn't really happen, so for simplicity
1283	 * simply ignore it, and let mac80211 reconfigure
1284	 * the sched scan later on.
1285	 */
1286	if (local->in_reconfig)
1287		return;
1288
1289	schedule_work(&local->sched_scan_stopped_work);
1290}
1291EXPORT_SYMBOL(ieee80211_sched_scan_stopped);