xref: /linux/net/mac80211/ibss.c (revision c0c914eca7f251c70facc37dfebeaf176601918d)
1 /*
2  * IBSS mode implementation
3  * Copyright 2003-2008, Jouni Malinen <j@w1.fi>
4  * Copyright 2004, Instant802 Networks, Inc.
5  * Copyright 2005, Devicescape Software, Inc.
6  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
7  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
8  * Copyright 2009, Johannes Berg <johannes@sipsolutions.net>
9  * Copyright 2013-2014  Intel Mobile Communications GmbH
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License version 2 as
13  * published by the Free Software Foundation.
14  */
15 
16 #include <linux/delay.h>
17 #include <linux/slab.h>
18 #include <linux/if_ether.h>
19 #include <linux/skbuff.h>
20 #include <linux/if_arp.h>
21 #include <linux/etherdevice.h>
22 #include <linux/rtnetlink.h>
23 #include <net/mac80211.h>
24 
25 #include "ieee80211_i.h"
26 #include "driver-ops.h"
27 #include "rate.h"
28 
29 #define IEEE80211_SCAN_INTERVAL (2 * HZ)
30 #define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)
31 
32 #define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
33 #define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)
34 #define IEEE80211_IBSS_RSN_INACTIVITY_LIMIT (10 * HZ)
35 
36 #define IEEE80211_IBSS_MAX_STA_ENTRIES 128
37 
38 static struct beacon_data *
39 ieee80211_ibss_build_presp(struct ieee80211_sub_if_data *sdata,
40 			   const int beacon_int, const u32 basic_rates,
41 			   const u16 capability, u64 tsf,
42 			   struct cfg80211_chan_def *chandef,
43 			   bool *have_higher_than_11mbit,
44 			   struct cfg80211_csa_settings *csa_settings)
45 {
46 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
47 	struct ieee80211_local *local = sdata->local;
48 	int rates_n = 0, i, ri;
49 	struct ieee80211_mgmt *mgmt;
50 	u8 *pos;
51 	struct ieee80211_supported_band *sband;
52 	u32 rate_flags, rates = 0, rates_added = 0;
53 	struct beacon_data *presp;
54 	int frame_len;
55 	int shift;
56 
57 	/* Build IBSS probe response */
58 	frame_len = sizeof(struct ieee80211_hdr_3addr) +
59 		    12 /* struct ieee80211_mgmt.u.beacon */ +
60 		    2 + IEEE80211_MAX_SSID_LEN /* max SSID */ +
61 		    2 + 8 /* max Supported Rates */ +
62 		    3 /* max DS params */ +
63 		    4 /* IBSS params */ +
64 		    5 /* Channel Switch Announcement */ +
65 		    2 + (IEEE80211_MAX_SUPP_RATES - 8) +
66 		    2 + sizeof(struct ieee80211_ht_cap) +
67 		    2 + sizeof(struct ieee80211_ht_operation) +
68 		    ifibss->ie_len;
69 	presp = kzalloc(sizeof(*presp) + frame_len, GFP_KERNEL);
70 	if (!presp)
71 		return NULL;
72 
73 	presp->head = (void *)(presp + 1);
74 
75 	mgmt = (void *) presp->head;
76 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
77 					  IEEE80211_STYPE_PROBE_RESP);
78 	eth_broadcast_addr(mgmt->da);
79 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
80 	memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
81 	mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
82 	mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
83 	mgmt->u.beacon.capab_info = cpu_to_le16(capability);
84 
85 	pos = (u8 *)mgmt + offsetof(struct ieee80211_mgmt, u.beacon.variable);
86 
87 	*pos++ = WLAN_EID_SSID;
88 	*pos++ = ifibss->ssid_len;
89 	memcpy(pos, ifibss->ssid, ifibss->ssid_len);
90 	pos += ifibss->ssid_len;
91 
92 	sband = local->hw.wiphy->bands[chandef->chan->band];
93 	rate_flags = ieee80211_chandef_rate_flags(chandef);
94 	shift = ieee80211_chandef_get_shift(chandef);
95 	rates_n = 0;
96 	if (have_higher_than_11mbit)
97 		*have_higher_than_11mbit = false;
98 
99 	for (i = 0; i < sband->n_bitrates; i++) {
100 		if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
101 			continue;
102 		if (sband->bitrates[i].bitrate > 110 &&
103 		    have_higher_than_11mbit)
104 			*have_higher_than_11mbit = true;
105 
106 		rates |= BIT(i);
107 		rates_n++;
108 	}
109 
110 	*pos++ = WLAN_EID_SUPP_RATES;
111 	*pos++ = min_t(int, 8, rates_n);
112 	for (ri = 0; ri < sband->n_bitrates; ri++) {
113 		int rate = DIV_ROUND_UP(sband->bitrates[ri].bitrate,
114 					5 * (1 << shift));
115 		u8 basic = 0;
116 		if (!(rates & BIT(ri)))
117 			continue;
118 
119 		if (basic_rates & BIT(ri))
120 			basic = 0x80;
121 		*pos++ = basic | (u8) rate;
122 		if (++rates_added == 8) {
123 			ri++; /* continue at next rate for EXT_SUPP_RATES */
124 			break;
125 		}
126 	}
127 
128 	if (sband->band == IEEE80211_BAND_2GHZ) {
129 		*pos++ = WLAN_EID_DS_PARAMS;
130 		*pos++ = 1;
131 		*pos++ = ieee80211_frequency_to_channel(
132 				chandef->chan->center_freq);
133 	}
134 
135 	*pos++ = WLAN_EID_IBSS_PARAMS;
136 	*pos++ = 2;
137 	/* FIX: set ATIM window based on scan results */
138 	*pos++ = 0;
139 	*pos++ = 0;
140 
141 	if (csa_settings) {
142 		*pos++ = WLAN_EID_CHANNEL_SWITCH;
143 		*pos++ = 3;
144 		*pos++ = csa_settings->block_tx ? 1 : 0;
145 		*pos++ = ieee80211_frequency_to_channel(
146 				csa_settings->chandef.chan->center_freq);
147 		presp->csa_counter_offsets[0] = (pos - presp->head);
148 		*pos++ = csa_settings->count;
149 		presp->csa_current_counter = csa_settings->count;
150 	}
151 
152 	/* put the remaining rates in WLAN_EID_EXT_SUPP_RATES */
153 	if (rates_n > 8) {
154 		*pos++ = WLAN_EID_EXT_SUPP_RATES;
155 		*pos++ = rates_n - 8;
156 		for (; ri < sband->n_bitrates; ri++) {
157 			int rate = DIV_ROUND_UP(sband->bitrates[ri].bitrate,
158 						5 * (1 << shift));
159 			u8 basic = 0;
160 			if (!(rates & BIT(ri)))
161 				continue;
162 
163 			if (basic_rates & BIT(ri))
164 				basic = 0x80;
165 			*pos++ = basic | (u8) rate;
166 		}
167 	}
168 
169 	if (ifibss->ie_len) {
170 		memcpy(pos, ifibss->ie, ifibss->ie_len);
171 		pos += ifibss->ie_len;
172 	}
173 
174 	/* add HT capability and information IEs */
175 	if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT &&
176 	    chandef->width != NL80211_CHAN_WIDTH_5 &&
177 	    chandef->width != NL80211_CHAN_WIDTH_10 &&
178 	    sband->ht_cap.ht_supported) {
179 		struct ieee80211_sta_ht_cap ht_cap;
180 
181 		memcpy(&ht_cap, &sband->ht_cap, sizeof(ht_cap));
182 		ieee80211_apply_htcap_overrides(sdata, &ht_cap);
183 
184 		pos = ieee80211_ie_build_ht_cap(pos, &ht_cap, ht_cap.cap);
185 		/*
186 		 * Note: According to 802.11n-2009 9.13.3.1, HT Protection
187 		 * field and RIFS Mode are reserved in IBSS mode, therefore
188 		 * keep them at 0
189 		 */
190 		pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap,
191 						 chandef, 0, false);
192 
193 		/* add VHT capability and information IEs */
194 		if (chandef->width != NL80211_CHAN_WIDTH_20 &&
195 		    chandef->width != NL80211_CHAN_WIDTH_40 &&
196 		    sband->vht_cap.vht_supported) {
197 			pos = ieee80211_ie_build_vht_cap(pos, &sband->vht_cap,
198 							 sband->vht_cap.cap);
199 			pos = ieee80211_ie_build_vht_oper(pos, &sband->vht_cap,
200 							  chandef);
201 		}
202 	}
203 
204 	if (local->hw.queues >= IEEE80211_NUM_ACS)
205 		pos = ieee80211_add_wmm_info_ie(pos, 0); /* U-APSD not in use */
206 
207 	presp->head_len = pos - presp->head;
208 	if (WARN_ON(presp->head_len > frame_len))
209 		goto error;
210 
211 	return presp;
212 error:
213 	kfree(presp);
214 	return NULL;
215 }
216 
217 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
218 				      const u8 *bssid, const int beacon_int,
219 				      struct cfg80211_chan_def *req_chandef,
220 				      const u32 basic_rates,
221 				      const u16 capability, u64 tsf,
222 				      bool creator)
223 {
224 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
225 	struct ieee80211_local *local = sdata->local;
226 	struct ieee80211_mgmt *mgmt;
227 	struct cfg80211_bss *bss;
228 	u32 bss_change;
229 	struct cfg80211_chan_def chandef;
230 	struct ieee80211_channel *chan;
231 	struct beacon_data *presp;
232 	struct cfg80211_inform_bss bss_meta = {};
233 	bool have_higher_than_11mbit;
234 	bool radar_required;
235 	int err;
236 
237 	sdata_assert_lock(sdata);
238 
239 	/* Reset own TSF to allow time synchronization work. */
240 	drv_reset_tsf(local, sdata);
241 
242 	if (!ether_addr_equal(ifibss->bssid, bssid))
243 		sta_info_flush(sdata);
244 
245 	/* if merging, indicate to driver that we leave the old IBSS */
246 	if (sdata->vif.bss_conf.ibss_joined) {
247 		sdata->vif.bss_conf.ibss_joined = false;
248 		sdata->vif.bss_conf.ibss_creator = false;
249 		sdata->vif.bss_conf.enable_beacon = false;
250 		netif_carrier_off(sdata->dev);
251 		ieee80211_bss_info_change_notify(sdata,
252 						 BSS_CHANGED_IBSS |
253 						 BSS_CHANGED_BEACON_ENABLED);
254 		drv_leave_ibss(local, sdata);
255 	}
256 
257 	presp = rcu_dereference_protected(ifibss->presp,
258 					  lockdep_is_held(&sdata->wdev.mtx));
259 	RCU_INIT_POINTER(ifibss->presp, NULL);
260 	if (presp)
261 		kfree_rcu(presp, rcu_head);
262 
263 	/* make a copy of the chandef, it could be modified below. */
264 	chandef = *req_chandef;
265 	chan = chandef.chan;
266 	if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef,
267 				     NL80211_IFTYPE_ADHOC)) {
268 		if (chandef.width == NL80211_CHAN_WIDTH_5 ||
269 		    chandef.width == NL80211_CHAN_WIDTH_10 ||
270 		    chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
271 		    chandef.width == NL80211_CHAN_WIDTH_20) {
272 			sdata_info(sdata,
273 				   "Failed to join IBSS, beacons forbidden\n");
274 			return;
275 		}
276 		chandef.width = NL80211_CHAN_WIDTH_20;
277 		chandef.center_freq1 = chan->center_freq;
278 		/* check again for downgraded chandef */
279 		if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef,
280 					     NL80211_IFTYPE_ADHOC)) {
281 			sdata_info(sdata,
282 				   "Failed to join IBSS, beacons forbidden\n");
283 			return;
284 		}
285 	}
286 
287 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
288 					    &chandef, NL80211_IFTYPE_ADHOC);
289 	if (err < 0) {
290 		sdata_info(sdata,
291 			   "Failed to join IBSS, invalid chandef\n");
292 		return;
293 	}
294 	if (err > 0 && !ifibss->userspace_handles_dfs) {
295 		sdata_info(sdata,
296 			   "Failed to join IBSS, DFS channel without control program\n");
297 		return;
298 	}
299 
300 	radar_required = err;
301 
302 	mutex_lock(&local->mtx);
303 	if (ieee80211_vif_use_channel(sdata, &chandef,
304 				      ifibss->fixed_channel ?
305 					IEEE80211_CHANCTX_SHARED :
306 					IEEE80211_CHANCTX_EXCLUSIVE)) {
307 		sdata_info(sdata, "Failed to join IBSS, no channel context\n");
308 		mutex_unlock(&local->mtx);
309 		return;
310 	}
311 	sdata->radar_required = radar_required;
312 	mutex_unlock(&local->mtx);
313 
314 	memcpy(ifibss->bssid, bssid, ETH_ALEN);
315 
316 	presp = ieee80211_ibss_build_presp(sdata, beacon_int, basic_rates,
317 					   capability, tsf, &chandef,
318 					   &have_higher_than_11mbit, NULL);
319 	if (!presp)
320 		return;
321 
322 	rcu_assign_pointer(ifibss->presp, presp);
323 	mgmt = (void *)presp->head;
324 
325 	sdata->vif.bss_conf.enable_beacon = true;
326 	sdata->vif.bss_conf.beacon_int = beacon_int;
327 	sdata->vif.bss_conf.basic_rates = basic_rates;
328 	sdata->vif.bss_conf.ssid_len = ifibss->ssid_len;
329 	memcpy(sdata->vif.bss_conf.ssid, ifibss->ssid, ifibss->ssid_len);
330 	bss_change = BSS_CHANGED_BEACON_INT;
331 	bss_change |= ieee80211_reset_erp_info(sdata);
332 	bss_change |= BSS_CHANGED_BSSID;
333 	bss_change |= BSS_CHANGED_BEACON;
334 	bss_change |= BSS_CHANGED_BEACON_ENABLED;
335 	bss_change |= BSS_CHANGED_BASIC_RATES;
336 	bss_change |= BSS_CHANGED_HT;
337 	bss_change |= BSS_CHANGED_IBSS;
338 	bss_change |= BSS_CHANGED_SSID;
339 
340 	/*
341 	 * In 5 GHz/802.11a, we can always use short slot time.
342 	 * (IEEE 802.11-2012 18.3.8.7)
343 	 *
344 	 * In 2.4GHz, we must always use long slots in IBSS for compatibility
345 	 * reasons.
346 	 * (IEEE 802.11-2012 19.4.5)
347 	 *
348 	 * HT follows these specifications (IEEE 802.11-2012 20.3.18)
349 	 */
350 	sdata->vif.bss_conf.use_short_slot = chan->band == IEEE80211_BAND_5GHZ;
351 	bss_change |= BSS_CHANGED_ERP_SLOT;
352 
353 	/* cf. IEEE 802.11 9.2.12 */
354 	if (chan->band == IEEE80211_BAND_2GHZ && have_higher_than_11mbit)
355 		sdata->flags |= IEEE80211_SDATA_OPERATING_GMODE;
356 	else
357 		sdata->flags &= ~IEEE80211_SDATA_OPERATING_GMODE;
358 
359 	ieee80211_set_wmm_default(sdata, true, false);
360 
361 	sdata->vif.bss_conf.ibss_joined = true;
362 	sdata->vif.bss_conf.ibss_creator = creator;
363 
364 	err = drv_join_ibss(local, sdata);
365 	if (err) {
366 		sdata->vif.bss_conf.ibss_joined = false;
367 		sdata->vif.bss_conf.ibss_creator = false;
368 		sdata->vif.bss_conf.enable_beacon = false;
369 		sdata->vif.bss_conf.ssid_len = 0;
370 		RCU_INIT_POINTER(ifibss->presp, NULL);
371 		kfree_rcu(presp, rcu_head);
372 		mutex_lock(&local->mtx);
373 		ieee80211_vif_release_channel(sdata);
374 		mutex_unlock(&local->mtx);
375 		sdata_info(sdata, "Failed to join IBSS, driver failure: %d\n",
376 			   err);
377 		return;
378 	}
379 
380 	ieee80211_bss_info_change_notify(sdata, bss_change);
381 
382 	ifibss->state = IEEE80211_IBSS_MLME_JOINED;
383 	mod_timer(&ifibss->timer,
384 		  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
385 
386 	bss_meta.chan = chan;
387 	bss_meta.scan_width = cfg80211_chandef_to_scan_width(&chandef);
388 	bss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta, mgmt,
389 					     presp->head_len, GFP_KERNEL);
390 
391 	cfg80211_put_bss(local->hw.wiphy, bss);
392 	netif_carrier_on(sdata->dev);
393 	cfg80211_ibss_joined(sdata->dev, ifibss->bssid, chan, GFP_KERNEL);
394 }
395 
396 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
397 				    struct ieee80211_bss *bss)
398 {
399 	struct cfg80211_bss *cbss =
400 		container_of((void *)bss, struct cfg80211_bss, priv);
401 	struct ieee80211_supported_band *sband;
402 	struct cfg80211_chan_def chandef;
403 	u32 basic_rates;
404 	int i, j;
405 	u16 beacon_int = cbss->beacon_interval;
406 	const struct cfg80211_bss_ies *ies;
407 	enum nl80211_channel_type chan_type;
408 	u64 tsf;
409 	u32 rate_flags;
410 	int shift;
411 
412 	sdata_assert_lock(sdata);
413 
414 	if (beacon_int < 10)
415 		beacon_int = 10;
416 
417 	switch (sdata->u.ibss.chandef.width) {
418 	case NL80211_CHAN_WIDTH_20_NOHT:
419 	case NL80211_CHAN_WIDTH_20:
420 	case NL80211_CHAN_WIDTH_40:
421 		chan_type = cfg80211_get_chandef_type(&sdata->u.ibss.chandef);
422 		cfg80211_chandef_create(&chandef, cbss->channel, chan_type);
423 		break;
424 	case NL80211_CHAN_WIDTH_5:
425 	case NL80211_CHAN_WIDTH_10:
426 		cfg80211_chandef_create(&chandef, cbss->channel,
427 					NL80211_CHAN_WIDTH_20_NOHT);
428 		chandef.width = sdata->u.ibss.chandef.width;
429 		break;
430 	case NL80211_CHAN_WIDTH_80:
431 	case NL80211_CHAN_WIDTH_80P80:
432 	case NL80211_CHAN_WIDTH_160:
433 		chandef = sdata->u.ibss.chandef;
434 		chandef.chan = cbss->channel;
435 		break;
436 	default:
437 		/* fall back to 20 MHz for unsupported modes */
438 		cfg80211_chandef_create(&chandef, cbss->channel,
439 					NL80211_CHAN_WIDTH_20_NOHT);
440 		break;
441 	}
442 
443 	sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
444 	rate_flags = ieee80211_chandef_rate_flags(&sdata->u.ibss.chandef);
445 	shift = ieee80211_vif_get_shift(&sdata->vif);
446 
447 	basic_rates = 0;
448 
449 	for (i = 0; i < bss->supp_rates_len; i++) {
450 		int rate = bss->supp_rates[i] & 0x7f;
451 		bool is_basic = !!(bss->supp_rates[i] & 0x80);
452 
453 		for (j = 0; j < sband->n_bitrates; j++) {
454 			int brate;
455 			if ((rate_flags & sband->bitrates[j].flags)
456 			    != rate_flags)
457 				continue;
458 
459 			brate = DIV_ROUND_UP(sband->bitrates[j].bitrate,
460 					     5 * (1 << shift));
461 			if (brate == rate) {
462 				if (is_basic)
463 					basic_rates |= BIT(j);
464 				break;
465 			}
466 		}
467 	}
468 
469 	rcu_read_lock();
470 	ies = rcu_dereference(cbss->ies);
471 	tsf = ies->tsf;
472 	rcu_read_unlock();
473 
474 	__ieee80211_sta_join_ibss(sdata, cbss->bssid,
475 				  beacon_int,
476 				  &chandef,
477 				  basic_rates,
478 				  cbss->capability,
479 				  tsf, false);
480 }
481 
482 int ieee80211_ibss_csa_beacon(struct ieee80211_sub_if_data *sdata,
483 			      struct cfg80211_csa_settings *csa_settings)
484 {
485 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
486 	struct beacon_data *presp, *old_presp;
487 	struct cfg80211_bss *cbss;
488 	const struct cfg80211_bss_ies *ies;
489 	u16 capability = 0;
490 	u64 tsf;
491 	int ret = 0;
492 
493 	sdata_assert_lock(sdata);
494 
495 	if (ifibss->privacy)
496 		capability = WLAN_CAPABILITY_PRIVACY;
497 
498 	cbss = cfg80211_get_bss(sdata->local->hw.wiphy, ifibss->chandef.chan,
499 				ifibss->bssid, ifibss->ssid,
500 				ifibss->ssid_len, IEEE80211_BSS_TYPE_IBSS,
501 				IEEE80211_PRIVACY(ifibss->privacy));
502 
503 	if (WARN_ON(!cbss)) {
504 		ret = -EINVAL;
505 		goto out;
506 	}
507 
508 	rcu_read_lock();
509 	ies = rcu_dereference(cbss->ies);
510 	tsf = ies->tsf;
511 	rcu_read_unlock();
512 	cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
513 
514 	old_presp = rcu_dereference_protected(ifibss->presp,
515 					  lockdep_is_held(&sdata->wdev.mtx));
516 
517 	presp = ieee80211_ibss_build_presp(sdata,
518 					   sdata->vif.bss_conf.beacon_int,
519 					   sdata->vif.bss_conf.basic_rates,
520 					   capability, tsf, &ifibss->chandef,
521 					   NULL, csa_settings);
522 	if (!presp) {
523 		ret = -ENOMEM;
524 		goto out;
525 	}
526 
527 	rcu_assign_pointer(ifibss->presp, presp);
528 	if (old_presp)
529 		kfree_rcu(old_presp, rcu_head);
530 
531 	return BSS_CHANGED_BEACON;
532  out:
533 	return ret;
534 }
535 
536 int ieee80211_ibss_finish_csa(struct ieee80211_sub_if_data *sdata)
537 {
538 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
539 	struct cfg80211_bss *cbss;
540 	int err, changed = 0;
541 
542 	sdata_assert_lock(sdata);
543 
544 	/* update cfg80211 bss information with the new channel */
545 	if (!is_zero_ether_addr(ifibss->bssid)) {
546 		cbss = cfg80211_get_bss(sdata->local->hw.wiphy,
547 					ifibss->chandef.chan,
548 					ifibss->bssid, ifibss->ssid,
549 					ifibss->ssid_len,
550 					IEEE80211_BSS_TYPE_IBSS,
551 					IEEE80211_PRIVACY(ifibss->privacy));
552 		/* XXX: should not really modify cfg80211 data */
553 		if (cbss) {
554 			cbss->channel = sdata->csa_chandef.chan;
555 			cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
556 		}
557 	}
558 
559 	ifibss->chandef = sdata->csa_chandef;
560 
561 	/* generate the beacon */
562 	err = ieee80211_ibss_csa_beacon(sdata, NULL);
563 	if (err < 0)
564 		return err;
565 
566 	changed |= err;
567 
568 	return changed;
569 }
570 
571 void ieee80211_ibss_stop(struct ieee80211_sub_if_data *sdata)
572 {
573 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
574 
575 	cancel_work_sync(&ifibss->csa_connection_drop_work);
576 }
577 
578 static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta)
579 	__acquires(RCU)
580 {
581 	struct ieee80211_sub_if_data *sdata = sta->sdata;
582 	u8 addr[ETH_ALEN];
583 
584 	memcpy(addr, sta->sta.addr, ETH_ALEN);
585 
586 	ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr);
587 
588 	sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
589 	sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
590 	/* authorize the station only if the network is not RSN protected. If
591 	 * not wait for the userspace to authorize it */
592 	if (!sta->sdata->u.ibss.control_port)
593 		sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
594 
595 	rate_control_rate_init(sta);
596 
597 	/* If it fails, maybe we raced another insertion? */
598 	if (sta_info_insert_rcu(sta))
599 		return sta_info_get(sdata, addr);
600 	return sta;
601 }
602 
603 static struct sta_info *
604 ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, const u8 *bssid,
605 		       const u8 *addr, u32 supp_rates)
606 	__acquires(RCU)
607 {
608 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
609 	struct ieee80211_local *local = sdata->local;
610 	struct sta_info *sta;
611 	struct ieee80211_chanctx_conf *chanctx_conf;
612 	struct ieee80211_supported_band *sband;
613 	enum nl80211_bss_scan_width scan_width;
614 	int band;
615 
616 	/*
617 	 * XXX: Consider removing the least recently used entry and
618 	 * 	allow new one to be added.
619 	 */
620 	if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
621 		net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
622 				    sdata->name, addr);
623 		rcu_read_lock();
624 		return NULL;
625 	}
626 
627 	if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) {
628 		rcu_read_lock();
629 		return NULL;
630 	}
631 
632 	if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) {
633 		rcu_read_lock();
634 		return NULL;
635 	}
636 
637 	rcu_read_lock();
638 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
639 	if (WARN_ON_ONCE(!chanctx_conf))
640 		return NULL;
641 	band = chanctx_conf->def.chan->band;
642 	scan_width = cfg80211_chandef_to_scan_width(&chanctx_conf->def);
643 	rcu_read_unlock();
644 
645 	sta = sta_info_alloc(sdata, addr, GFP_KERNEL);
646 	if (!sta) {
647 		rcu_read_lock();
648 		return NULL;
649 	}
650 
651 	sta->rx_stats.last_rx = jiffies;
652 
653 	/* make sure mandatory rates are always added */
654 	sband = local->hw.wiphy->bands[band];
655 	sta->sta.supp_rates[band] = supp_rates |
656 			ieee80211_mandatory_rates(sband, scan_width);
657 
658 	return ieee80211_ibss_finish_sta(sta);
659 }
660 
661 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
662 {
663 	struct ieee80211_local *local = sdata->local;
664 	int active = 0;
665 	struct sta_info *sta;
666 
667 	sdata_assert_lock(sdata);
668 
669 	rcu_read_lock();
670 
671 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
672 		if (sta->sdata == sdata &&
673 		    time_after(sta->rx_stats.last_rx +
674 			       IEEE80211_IBSS_MERGE_INTERVAL,
675 			       jiffies)) {
676 			active++;
677 			break;
678 		}
679 	}
680 
681 	rcu_read_unlock();
682 
683 	return active;
684 }
685 
686 static void ieee80211_ibss_disconnect(struct ieee80211_sub_if_data *sdata)
687 {
688 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
689 	struct ieee80211_local *local = sdata->local;
690 	struct cfg80211_bss *cbss;
691 	struct beacon_data *presp;
692 	struct sta_info *sta;
693 
694 	if (!is_zero_ether_addr(ifibss->bssid)) {
695 		cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->chandef.chan,
696 					ifibss->bssid, ifibss->ssid,
697 					ifibss->ssid_len,
698 					IEEE80211_BSS_TYPE_IBSS,
699 					IEEE80211_PRIVACY(ifibss->privacy));
700 
701 		if (cbss) {
702 			cfg80211_unlink_bss(local->hw.wiphy, cbss);
703 			cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
704 		}
705 	}
706 
707 	ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
708 
709 	sta_info_flush(sdata);
710 
711 	spin_lock_bh(&ifibss->incomplete_lock);
712 	while (!list_empty(&ifibss->incomplete_stations)) {
713 		sta = list_first_entry(&ifibss->incomplete_stations,
714 				       struct sta_info, list);
715 		list_del(&sta->list);
716 		spin_unlock_bh(&ifibss->incomplete_lock);
717 
718 		sta_info_free(local, sta);
719 		spin_lock_bh(&ifibss->incomplete_lock);
720 	}
721 	spin_unlock_bh(&ifibss->incomplete_lock);
722 
723 	netif_carrier_off(sdata->dev);
724 
725 	sdata->vif.bss_conf.ibss_joined = false;
726 	sdata->vif.bss_conf.ibss_creator = false;
727 	sdata->vif.bss_conf.enable_beacon = false;
728 	sdata->vif.bss_conf.ssid_len = 0;
729 
730 	/* remove beacon */
731 	presp = rcu_dereference_protected(ifibss->presp,
732 					  lockdep_is_held(&sdata->wdev.mtx));
733 	RCU_INIT_POINTER(sdata->u.ibss.presp, NULL);
734 	if (presp)
735 		kfree_rcu(presp, rcu_head);
736 
737 	clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
738 	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
739 						BSS_CHANGED_IBSS);
740 	drv_leave_ibss(local, sdata);
741 	mutex_lock(&local->mtx);
742 	ieee80211_vif_release_channel(sdata);
743 	mutex_unlock(&local->mtx);
744 }
745 
746 static void ieee80211_csa_connection_drop_work(struct work_struct *work)
747 {
748 	struct ieee80211_sub_if_data *sdata =
749 		container_of(work, struct ieee80211_sub_if_data,
750 			     u.ibss.csa_connection_drop_work);
751 
752 	sdata_lock(sdata);
753 
754 	ieee80211_ibss_disconnect(sdata);
755 	synchronize_rcu();
756 	skb_queue_purge(&sdata->skb_queue);
757 
758 	/* trigger a scan to find another IBSS network to join */
759 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
760 
761 	sdata_unlock(sdata);
762 }
763 
764 static void ieee80211_ibss_csa_mark_radar(struct ieee80211_sub_if_data *sdata)
765 {
766 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
767 	int err;
768 
769 	/* if the current channel is a DFS channel, mark the channel as
770 	 * unavailable.
771 	 */
772 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
773 					    &ifibss->chandef,
774 					    NL80211_IFTYPE_ADHOC);
775 	if (err > 0)
776 		cfg80211_radar_event(sdata->local->hw.wiphy, &ifibss->chandef,
777 				     GFP_ATOMIC);
778 }
779 
780 static bool
781 ieee80211_ibss_process_chanswitch(struct ieee80211_sub_if_data *sdata,
782 				  struct ieee802_11_elems *elems,
783 				  bool beacon)
784 {
785 	struct cfg80211_csa_settings params;
786 	struct ieee80211_csa_ie csa_ie;
787 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
788 	enum nl80211_channel_type ch_type;
789 	int err;
790 	u32 sta_flags;
791 
792 	sdata_assert_lock(sdata);
793 
794 	sta_flags = IEEE80211_STA_DISABLE_VHT;
795 	switch (ifibss->chandef.width) {
796 	case NL80211_CHAN_WIDTH_5:
797 	case NL80211_CHAN_WIDTH_10:
798 	case NL80211_CHAN_WIDTH_20_NOHT:
799 		sta_flags |= IEEE80211_STA_DISABLE_HT;
800 		/* fall through */
801 	case NL80211_CHAN_WIDTH_20:
802 		sta_flags |= IEEE80211_STA_DISABLE_40MHZ;
803 		break;
804 	default:
805 		break;
806 	}
807 
808 	memset(&params, 0, sizeof(params));
809 	memset(&csa_ie, 0, sizeof(csa_ie));
810 	err = ieee80211_parse_ch_switch_ie(sdata, elems,
811 					   ifibss->chandef.chan->band,
812 					   sta_flags, ifibss->bssid, &csa_ie);
813 	/* can't switch to destination channel, fail */
814 	if (err < 0)
815 		goto disconnect;
816 
817 	/* did not contain a CSA */
818 	if (err)
819 		return false;
820 
821 	/* channel switch is not supported, disconnect */
822 	if (!(sdata->local->hw.wiphy->flags & WIPHY_FLAG_HAS_CHANNEL_SWITCH))
823 		goto disconnect;
824 
825 	params.count = csa_ie.count;
826 	params.chandef = csa_ie.chandef;
827 
828 	switch (ifibss->chandef.width) {
829 	case NL80211_CHAN_WIDTH_20_NOHT:
830 	case NL80211_CHAN_WIDTH_20:
831 	case NL80211_CHAN_WIDTH_40:
832 		/* keep our current HT mode (HT20/HT40+/HT40-), even if
833 		 * another mode  has been announced. The mode is not adopted
834 		 * within the beacon while doing CSA and we should therefore
835 		 * keep the mode which we announce.
836 		 */
837 		ch_type = cfg80211_get_chandef_type(&ifibss->chandef);
838 		cfg80211_chandef_create(&params.chandef, params.chandef.chan,
839 					ch_type);
840 		break;
841 	case NL80211_CHAN_WIDTH_5:
842 	case NL80211_CHAN_WIDTH_10:
843 		if (params.chandef.width != ifibss->chandef.width) {
844 			sdata_info(sdata,
845 				   "IBSS %pM received channel switch from incompatible channel width (%d MHz, width:%d, CF1/2: %d/%d MHz), disconnecting\n",
846 				   ifibss->bssid,
847 				   params.chandef.chan->center_freq,
848 				   params.chandef.width,
849 				   params.chandef.center_freq1,
850 				   params.chandef.center_freq2);
851 			goto disconnect;
852 		}
853 		break;
854 	default:
855 		/* should not happen, sta_flags should prevent VHT modes. */
856 		WARN_ON(1);
857 		goto disconnect;
858 	}
859 
860 	if (!cfg80211_reg_can_beacon(sdata->local->hw.wiphy, &params.chandef,
861 				     NL80211_IFTYPE_ADHOC)) {
862 		sdata_info(sdata,
863 			   "IBSS %pM switches to unsupported channel (%d MHz, width:%d, CF1/2: %d/%d MHz), disconnecting\n",
864 			   ifibss->bssid,
865 			   params.chandef.chan->center_freq,
866 			   params.chandef.width,
867 			   params.chandef.center_freq1,
868 			   params.chandef.center_freq2);
869 		goto disconnect;
870 	}
871 
872 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
873 					    &params.chandef,
874 					    NL80211_IFTYPE_ADHOC);
875 	if (err < 0)
876 		goto disconnect;
877 	if (err > 0 && !ifibss->userspace_handles_dfs) {
878 		/* IBSS-DFS only allowed with a control program */
879 		goto disconnect;
880 	}
881 
882 	params.radar_required = err;
883 
884 	if (cfg80211_chandef_identical(&params.chandef,
885 				       &sdata->vif.bss_conf.chandef)) {
886 		ibss_dbg(sdata,
887 			 "received csa with an identical chandef, ignoring\n");
888 		return true;
889 	}
890 
891 	/* all checks done, now perform the channel switch. */
892 	ibss_dbg(sdata,
893 		 "received channel switch announcement to go to channel %d MHz\n",
894 		 params.chandef.chan->center_freq);
895 
896 	params.block_tx = !!csa_ie.mode;
897 
898 	if (ieee80211_channel_switch(sdata->local->hw.wiphy, sdata->dev,
899 				     &params))
900 		goto disconnect;
901 
902 	ieee80211_ibss_csa_mark_radar(sdata);
903 
904 	return true;
905 disconnect:
906 	ibss_dbg(sdata, "Can't handle channel switch, disconnect\n");
907 	ieee80211_queue_work(&sdata->local->hw,
908 			     &ifibss->csa_connection_drop_work);
909 
910 	ieee80211_ibss_csa_mark_radar(sdata);
911 
912 	return true;
913 }
914 
915 static void
916 ieee80211_rx_mgmt_spectrum_mgmt(struct ieee80211_sub_if_data *sdata,
917 				struct ieee80211_mgmt *mgmt, size_t len,
918 				struct ieee80211_rx_status *rx_status,
919 				struct ieee802_11_elems *elems)
920 {
921 	int required_len;
922 
923 	if (len < IEEE80211_MIN_ACTION_SIZE + 1)
924 		return;
925 
926 	/* CSA is the only action we handle for now */
927 	if (mgmt->u.action.u.measurement.action_code !=
928 	    WLAN_ACTION_SPCT_CHL_SWITCH)
929 		return;
930 
931 	required_len = IEEE80211_MIN_ACTION_SIZE +
932 		       sizeof(mgmt->u.action.u.chan_switch);
933 	if (len < required_len)
934 		return;
935 
936 	if (!sdata->vif.csa_active)
937 		ieee80211_ibss_process_chanswitch(sdata, elems, false);
938 }
939 
940 static void ieee80211_rx_mgmt_deauth_ibss(struct ieee80211_sub_if_data *sdata,
941 					  struct ieee80211_mgmt *mgmt,
942 					  size_t len)
943 {
944 	u16 reason = le16_to_cpu(mgmt->u.deauth.reason_code);
945 
946 	if (len < IEEE80211_DEAUTH_FRAME_LEN)
947 		return;
948 
949 	ibss_dbg(sdata, "RX DeAuth SA=%pM DA=%pM BSSID=%pM (reason: %d)\n",
950 		 mgmt->sa, mgmt->da, mgmt->bssid, reason);
951 	sta_info_destroy_addr(sdata, mgmt->sa);
952 }
953 
954 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
955 					struct ieee80211_mgmt *mgmt,
956 					size_t len)
957 {
958 	u16 auth_alg, auth_transaction;
959 
960 	sdata_assert_lock(sdata);
961 
962 	if (len < 24 + 6)
963 		return;
964 
965 	auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
966 	auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
967 
968 	ibss_dbg(sdata,
969 		 "RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n",
970 		 mgmt->sa, mgmt->da, mgmt->bssid, auth_transaction);
971 
972 	if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1)
973 		return;
974 
975 	/*
976 	 * IEEE 802.11 standard does not require authentication in IBSS
977 	 * networks and most implementations do not seem to use it.
978 	 * However, try to reply to authentication attempts if someone
979 	 * has actually implemented this.
980 	 */
981 	ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, 0, NULL, 0,
982 			    mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0, 0);
983 }
984 
985 static void ieee80211_update_sta_info(struct ieee80211_sub_if_data *sdata,
986 				      struct ieee80211_mgmt *mgmt, size_t len,
987 				      struct ieee80211_rx_status *rx_status,
988 				      struct ieee802_11_elems *elems,
989 				      struct ieee80211_channel *channel)
990 {
991 	struct sta_info *sta;
992 	enum ieee80211_band band = rx_status->band;
993 	enum nl80211_bss_scan_width scan_width;
994 	struct ieee80211_local *local = sdata->local;
995 	struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
996 	bool rates_updated = false;
997 	u32 supp_rates = 0;
998 
999 	if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
1000 		return;
1001 
1002 	if (!ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid))
1003 		return;
1004 
1005 	rcu_read_lock();
1006 	sta = sta_info_get(sdata, mgmt->sa);
1007 
1008 	if (elems->supp_rates) {
1009 		supp_rates = ieee80211_sta_get_rates(sdata, elems,
1010 						     band, NULL);
1011 		if (sta) {
1012 			u32 prev_rates;
1013 
1014 			prev_rates = sta->sta.supp_rates[band];
1015 			/* make sure mandatory rates are always added */
1016 			scan_width = NL80211_BSS_CHAN_WIDTH_20;
1017 			if (rx_status->flag & RX_FLAG_5MHZ)
1018 				scan_width = NL80211_BSS_CHAN_WIDTH_5;
1019 			if (rx_status->flag & RX_FLAG_10MHZ)
1020 				scan_width = NL80211_BSS_CHAN_WIDTH_10;
1021 
1022 			sta->sta.supp_rates[band] = supp_rates |
1023 				ieee80211_mandatory_rates(sband, scan_width);
1024 			if (sta->sta.supp_rates[band] != prev_rates) {
1025 				ibss_dbg(sdata,
1026 					 "updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n",
1027 					 sta->sta.addr, prev_rates,
1028 					 sta->sta.supp_rates[band]);
1029 				rates_updated = true;
1030 			}
1031 		} else {
1032 			rcu_read_unlock();
1033 			sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
1034 						     mgmt->sa, supp_rates);
1035 		}
1036 	}
1037 
1038 	if (sta && !sta->sta.wme &&
1039 	    elems->wmm_info && local->hw.queues >= IEEE80211_NUM_ACS) {
1040 		sta->sta.wme = true;
1041 		ieee80211_check_fast_xmit(sta);
1042 	}
1043 
1044 	if (sta && elems->ht_operation && elems->ht_cap_elem &&
1045 	    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_20_NOHT &&
1046 	    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_5 &&
1047 	    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_10) {
1048 		/* we both use HT */
1049 		struct ieee80211_ht_cap htcap_ie;
1050 		struct cfg80211_chan_def chandef;
1051 		enum ieee80211_sta_rx_bandwidth bw = sta->sta.bandwidth;
1052 
1053 		ieee80211_ht_oper_to_chandef(channel,
1054 					     elems->ht_operation,
1055 					     &chandef);
1056 
1057 		memcpy(&htcap_ie, elems->ht_cap_elem, sizeof(htcap_ie));
1058 		rates_updated |= ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
1059 								   &htcap_ie,
1060 								   sta);
1061 
1062 		if (elems->vht_operation && elems->vht_cap_elem &&
1063 		    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_20 &&
1064 		    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_40) {
1065 			/* we both use VHT */
1066 			struct ieee80211_vht_cap cap_ie;
1067 			struct ieee80211_sta_vht_cap cap = sta->sta.vht_cap;
1068 
1069 			ieee80211_vht_oper_to_chandef(channel,
1070 						      elems->vht_operation,
1071 						      &chandef);
1072 			memcpy(&cap_ie, elems->vht_cap_elem, sizeof(cap_ie));
1073 			ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband,
1074 							    &cap_ie, sta);
1075 			if (memcmp(&cap, &sta->sta.vht_cap, sizeof(cap)))
1076 				rates_updated |= true;
1077 		}
1078 
1079 		if (bw != sta->sta.bandwidth)
1080 			rates_updated |= true;
1081 
1082 		if (!cfg80211_chandef_compatible(&sdata->u.ibss.chandef,
1083 						 &chandef))
1084 			WARN_ON_ONCE(1);
1085 	}
1086 
1087 	if (sta && rates_updated) {
1088 		u32 changed = IEEE80211_RC_SUPP_RATES_CHANGED;
1089 		u8 rx_nss = sta->sta.rx_nss;
1090 
1091 		/* Force rx_nss recalculation */
1092 		sta->sta.rx_nss = 0;
1093 		rate_control_rate_init(sta);
1094 		if (sta->sta.rx_nss != rx_nss)
1095 			changed |= IEEE80211_RC_NSS_CHANGED;
1096 
1097 		drv_sta_rc_update(local, sdata, &sta->sta, changed);
1098 	}
1099 
1100 	rcu_read_unlock();
1101 }
1102 
1103 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
1104 				  struct ieee80211_mgmt *mgmt, size_t len,
1105 				  struct ieee80211_rx_status *rx_status,
1106 				  struct ieee802_11_elems *elems)
1107 {
1108 	struct ieee80211_local *local = sdata->local;
1109 	struct cfg80211_bss *cbss;
1110 	struct ieee80211_bss *bss;
1111 	struct ieee80211_channel *channel;
1112 	u64 beacon_timestamp, rx_timestamp;
1113 	u32 supp_rates = 0;
1114 	enum ieee80211_band band = rx_status->band;
1115 
1116 	channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
1117 	if (!channel)
1118 		return;
1119 
1120 	ieee80211_update_sta_info(sdata, mgmt, len, rx_status, elems, channel);
1121 
1122 	bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
1123 					channel);
1124 	if (!bss)
1125 		return;
1126 
1127 	cbss = container_of((void *)bss, struct cfg80211_bss, priv);
1128 
1129 	/* same for beacon and probe response */
1130 	beacon_timestamp = le64_to_cpu(mgmt->u.beacon.timestamp);
1131 
1132 	/* check if we need to merge IBSS */
1133 
1134 	/* not an IBSS */
1135 	if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
1136 		goto put_bss;
1137 
1138 	/* different channel */
1139 	if (sdata->u.ibss.fixed_channel &&
1140 	    sdata->u.ibss.chandef.chan != cbss->channel)
1141 		goto put_bss;
1142 
1143 	/* different SSID */
1144 	if (elems->ssid_len != sdata->u.ibss.ssid_len ||
1145 	    memcmp(elems->ssid, sdata->u.ibss.ssid,
1146 				sdata->u.ibss.ssid_len))
1147 		goto put_bss;
1148 
1149 	/* process channel switch */
1150 	if (sdata->vif.csa_active ||
1151 	    ieee80211_ibss_process_chanswitch(sdata, elems, true))
1152 		goto put_bss;
1153 
1154 	/* same BSSID */
1155 	if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid))
1156 		goto put_bss;
1157 
1158 	/* we use a fixed BSSID */
1159 	if (sdata->u.ibss.fixed_bssid)
1160 		goto put_bss;
1161 
1162 	if (ieee80211_have_rx_timestamp(rx_status)) {
1163 		/* time when timestamp field was received */
1164 		rx_timestamp =
1165 			ieee80211_calculate_rx_timestamp(local, rx_status,
1166 							 len + FCS_LEN, 24);
1167 	} else {
1168 		/*
1169 		 * second best option: get current TSF
1170 		 * (will return -1 if not supported)
1171 		 */
1172 		rx_timestamp = drv_get_tsf(local, sdata);
1173 	}
1174 
1175 	ibss_dbg(sdata,
1176 		 "RX beacon SA=%pM BSSID=%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
1177 		 mgmt->sa, mgmt->bssid,
1178 		 (unsigned long long)rx_timestamp,
1179 		 (unsigned long long)beacon_timestamp,
1180 		 (unsigned long long)(rx_timestamp - beacon_timestamp),
1181 		 jiffies);
1182 
1183 	if (beacon_timestamp > rx_timestamp) {
1184 		ibss_dbg(sdata,
1185 			 "beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n",
1186 			 mgmt->bssid);
1187 		ieee80211_sta_join_ibss(sdata, bss);
1188 		supp_rates = ieee80211_sta_get_rates(sdata, elems, band, NULL);
1189 		ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
1190 				       supp_rates);
1191 		rcu_read_unlock();
1192 	}
1193 
1194  put_bss:
1195 	ieee80211_rx_bss_put(local, bss);
1196 }
1197 
1198 void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata,
1199 			      const u8 *bssid, const u8 *addr,
1200 			      u32 supp_rates)
1201 {
1202 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1203 	struct ieee80211_local *local = sdata->local;
1204 	struct sta_info *sta;
1205 	struct ieee80211_chanctx_conf *chanctx_conf;
1206 	struct ieee80211_supported_band *sband;
1207 	enum nl80211_bss_scan_width scan_width;
1208 	int band;
1209 
1210 	/*
1211 	 * XXX: Consider removing the least recently used entry and
1212 	 * 	allow new one to be added.
1213 	 */
1214 	if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
1215 		net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
1216 				    sdata->name, addr);
1217 		return;
1218 	}
1219 
1220 	if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
1221 		return;
1222 
1223 	if (!ether_addr_equal(bssid, sdata->u.ibss.bssid))
1224 		return;
1225 
1226 	rcu_read_lock();
1227 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
1228 	if (WARN_ON_ONCE(!chanctx_conf)) {
1229 		rcu_read_unlock();
1230 		return;
1231 	}
1232 	band = chanctx_conf->def.chan->band;
1233 	scan_width = cfg80211_chandef_to_scan_width(&chanctx_conf->def);
1234 	rcu_read_unlock();
1235 
1236 	sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
1237 	if (!sta)
1238 		return;
1239 
1240 	sta->rx_stats.last_rx = jiffies;
1241 
1242 	/* make sure mandatory rates are always added */
1243 	sband = local->hw.wiphy->bands[band];
1244 	sta->sta.supp_rates[band] = supp_rates |
1245 			ieee80211_mandatory_rates(sband, scan_width);
1246 
1247 	spin_lock(&ifibss->incomplete_lock);
1248 	list_add(&sta->list, &ifibss->incomplete_stations);
1249 	spin_unlock(&ifibss->incomplete_lock);
1250 	ieee80211_queue_work(&local->hw, &sdata->work);
1251 }
1252 
1253 static void ieee80211_ibss_sta_expire(struct ieee80211_sub_if_data *sdata)
1254 {
1255 	struct ieee80211_local *local = sdata->local;
1256 	struct sta_info *sta, *tmp;
1257 	unsigned long exp_time = IEEE80211_IBSS_INACTIVITY_LIMIT;
1258 	unsigned long exp_rsn = IEEE80211_IBSS_RSN_INACTIVITY_LIMIT;
1259 
1260 	mutex_lock(&local->sta_mtx);
1261 
1262 	list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
1263 		if (sdata != sta->sdata)
1264 			continue;
1265 
1266 		if (time_after(jiffies, sta->rx_stats.last_rx + exp_time) ||
1267 		    (time_after(jiffies, sta->rx_stats.last_rx + exp_rsn) &&
1268 		     sta->sta_state != IEEE80211_STA_AUTHORIZED)) {
1269 			sta_dbg(sta->sdata, "expiring inactive %sSTA %pM\n",
1270 				sta->sta_state != IEEE80211_STA_AUTHORIZED ?
1271 				"not authorized " : "", sta->sta.addr);
1272 
1273 			WARN_ON(__sta_info_destroy(sta));
1274 		}
1275 	}
1276 
1277 	mutex_unlock(&local->sta_mtx);
1278 }
1279 
1280 /*
1281  * This function is called with state == IEEE80211_IBSS_MLME_JOINED
1282  */
1283 
1284 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
1285 {
1286 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1287 	enum nl80211_bss_scan_width scan_width;
1288 
1289 	sdata_assert_lock(sdata);
1290 
1291 	mod_timer(&ifibss->timer,
1292 		  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
1293 
1294 	ieee80211_ibss_sta_expire(sdata);
1295 
1296 	if (time_before(jiffies, ifibss->last_scan_completed +
1297 		       IEEE80211_IBSS_MERGE_INTERVAL))
1298 		return;
1299 
1300 	if (ieee80211_sta_active_ibss(sdata))
1301 		return;
1302 
1303 	if (ifibss->fixed_channel)
1304 		return;
1305 
1306 	sdata_info(sdata,
1307 		   "No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n");
1308 
1309 	scan_width = cfg80211_chandef_to_scan_width(&ifibss->chandef);
1310 	ieee80211_request_ibss_scan(sdata, ifibss->ssid, ifibss->ssid_len,
1311 				    NULL, 0, scan_width);
1312 }
1313 
1314 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
1315 {
1316 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1317 	u8 bssid[ETH_ALEN];
1318 	u16 capability;
1319 	int i;
1320 
1321 	sdata_assert_lock(sdata);
1322 
1323 	if (ifibss->fixed_bssid) {
1324 		memcpy(bssid, ifibss->bssid, ETH_ALEN);
1325 	} else {
1326 		/* Generate random, not broadcast, locally administered BSSID. Mix in
1327 		 * own MAC address to make sure that devices that do not have proper
1328 		 * random number generator get different BSSID. */
1329 		get_random_bytes(bssid, ETH_ALEN);
1330 		for (i = 0; i < ETH_ALEN; i++)
1331 			bssid[i] ^= sdata->vif.addr[i];
1332 		bssid[0] &= ~0x01;
1333 		bssid[0] |= 0x02;
1334 	}
1335 
1336 	sdata_info(sdata, "Creating new IBSS network, BSSID %pM\n", bssid);
1337 
1338 	capability = WLAN_CAPABILITY_IBSS;
1339 
1340 	if (ifibss->privacy)
1341 		capability |= WLAN_CAPABILITY_PRIVACY;
1342 
1343 	__ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
1344 				  &ifibss->chandef, ifibss->basic_rates,
1345 				  capability, 0, true);
1346 }
1347 
1348 static unsigned ibss_setup_channels(struct wiphy *wiphy,
1349 				    struct ieee80211_channel **channels,
1350 				    unsigned int channels_max,
1351 				    u32 center_freq, u32 width)
1352 {
1353 	struct ieee80211_channel *chan = NULL;
1354 	unsigned int n_chan = 0;
1355 	u32 start_freq, end_freq, freq;
1356 
1357 	if (width <= 20) {
1358 		start_freq = center_freq;
1359 		end_freq = center_freq;
1360 	} else {
1361 		start_freq = center_freq - width / 2 + 10;
1362 		end_freq = center_freq + width / 2 - 10;
1363 	}
1364 
1365 	for (freq = start_freq; freq <= end_freq; freq += 20) {
1366 		chan = ieee80211_get_channel(wiphy, freq);
1367 		if (!chan)
1368 			continue;
1369 		if (n_chan >= channels_max)
1370 			return n_chan;
1371 
1372 		channels[n_chan] = chan;
1373 		n_chan++;
1374 	}
1375 
1376 	return n_chan;
1377 }
1378 
1379 static unsigned int
1380 ieee80211_ibss_setup_scan_channels(struct wiphy *wiphy,
1381 				   const struct cfg80211_chan_def *chandef,
1382 				   struct ieee80211_channel **channels,
1383 				   unsigned int channels_max)
1384 {
1385 	unsigned int n_chan = 0;
1386 	u32 width, cf1, cf2 = 0;
1387 
1388 	switch (chandef->width) {
1389 	case NL80211_CHAN_WIDTH_40:
1390 		width = 40;
1391 		break;
1392 	case NL80211_CHAN_WIDTH_80P80:
1393 		cf2 = chandef->center_freq2;
1394 		/* fall through */
1395 	case NL80211_CHAN_WIDTH_80:
1396 		width = 80;
1397 		break;
1398 	case NL80211_CHAN_WIDTH_160:
1399 		width = 160;
1400 		break;
1401 	default:
1402 		width = 20;
1403 		break;
1404 	}
1405 
1406 	cf1 = chandef->center_freq1;
1407 
1408 	n_chan = ibss_setup_channels(wiphy, channels, channels_max, cf1, width);
1409 
1410 	if (cf2)
1411 		n_chan += ibss_setup_channels(wiphy, &channels[n_chan],
1412 					      channels_max - n_chan, cf2,
1413 					      width);
1414 
1415 	return n_chan;
1416 }
1417 
1418 /*
1419  * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
1420  */
1421 
1422 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
1423 {
1424 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1425 	struct ieee80211_local *local = sdata->local;
1426 	struct cfg80211_bss *cbss;
1427 	struct ieee80211_channel *chan = NULL;
1428 	const u8 *bssid = NULL;
1429 	enum nl80211_bss_scan_width scan_width;
1430 	int active_ibss;
1431 
1432 	sdata_assert_lock(sdata);
1433 
1434 	active_ibss = ieee80211_sta_active_ibss(sdata);
1435 	ibss_dbg(sdata, "sta_find_ibss (active_ibss=%d)\n", active_ibss);
1436 
1437 	if (active_ibss)
1438 		return;
1439 
1440 	if (ifibss->fixed_bssid)
1441 		bssid = ifibss->bssid;
1442 	if (ifibss->fixed_channel)
1443 		chan = ifibss->chandef.chan;
1444 	if (!is_zero_ether_addr(ifibss->bssid))
1445 		bssid = ifibss->bssid;
1446 	cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
1447 				ifibss->ssid, ifibss->ssid_len,
1448 				IEEE80211_BSS_TYPE_IBSS,
1449 				IEEE80211_PRIVACY(ifibss->privacy));
1450 
1451 	if (cbss) {
1452 		struct ieee80211_bss *bss;
1453 
1454 		bss = (void *)cbss->priv;
1455 		ibss_dbg(sdata,
1456 			 "sta_find_ibss: selected %pM current %pM\n",
1457 			 cbss->bssid, ifibss->bssid);
1458 		sdata_info(sdata,
1459 			   "Selected IBSS BSSID %pM based on configured SSID\n",
1460 			   cbss->bssid);
1461 
1462 		ieee80211_sta_join_ibss(sdata, bss);
1463 		ieee80211_rx_bss_put(local, bss);
1464 		return;
1465 	}
1466 
1467 	/* if a fixed bssid and a fixed freq have been provided create the IBSS
1468 	 * directly and do not waste time scanning
1469 	 */
1470 	if (ifibss->fixed_bssid && ifibss->fixed_channel) {
1471 		sdata_info(sdata, "Created IBSS using preconfigured BSSID %pM\n",
1472 			   bssid);
1473 		ieee80211_sta_create_ibss(sdata);
1474 		return;
1475 	}
1476 
1477 
1478 	ibss_dbg(sdata, "sta_find_ibss: did not try to join ibss\n");
1479 
1480 	/* Selected IBSS not found in current scan results - try to scan */
1481 	if (time_after(jiffies, ifibss->last_scan_completed +
1482 					IEEE80211_SCAN_INTERVAL)) {
1483 		struct ieee80211_channel *channels[8];
1484 		unsigned int num;
1485 
1486 		sdata_info(sdata, "Trigger new scan to find an IBSS to join\n");
1487 
1488 		num = ieee80211_ibss_setup_scan_channels(local->hw.wiphy,
1489 							 &ifibss->chandef,
1490 							 channels,
1491 							 ARRAY_SIZE(channels));
1492 		scan_width = cfg80211_chandef_to_scan_width(&ifibss->chandef);
1493 		ieee80211_request_ibss_scan(sdata, ifibss->ssid,
1494 					    ifibss->ssid_len, channels, num,
1495 					    scan_width);
1496 	} else {
1497 		int interval = IEEE80211_SCAN_INTERVAL;
1498 
1499 		if (time_after(jiffies, ifibss->ibss_join_req +
1500 			       IEEE80211_IBSS_JOIN_TIMEOUT))
1501 			ieee80211_sta_create_ibss(sdata);
1502 
1503 		mod_timer(&ifibss->timer,
1504 			  round_jiffies(jiffies + interval));
1505 	}
1506 }
1507 
1508 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
1509 					struct sk_buff *req)
1510 {
1511 	struct ieee80211_mgmt *mgmt = (void *)req->data;
1512 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1513 	struct ieee80211_local *local = sdata->local;
1514 	int tx_last_beacon, len = req->len;
1515 	struct sk_buff *skb;
1516 	struct beacon_data *presp;
1517 	u8 *pos, *end;
1518 
1519 	sdata_assert_lock(sdata);
1520 
1521 	presp = rcu_dereference_protected(ifibss->presp,
1522 					  lockdep_is_held(&sdata->wdev.mtx));
1523 
1524 	if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
1525 	    len < 24 + 2 || !presp)
1526 		return;
1527 
1528 	tx_last_beacon = drv_tx_last_beacon(local);
1529 
1530 	ibss_dbg(sdata,
1531 		 "RX ProbeReq SA=%pM DA=%pM BSSID=%pM (tx_last_beacon=%d)\n",
1532 		 mgmt->sa, mgmt->da, mgmt->bssid, tx_last_beacon);
1533 
1534 	if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da))
1535 		return;
1536 
1537 	if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) &&
1538 	    !is_broadcast_ether_addr(mgmt->bssid))
1539 		return;
1540 
1541 	end = ((u8 *) mgmt) + len;
1542 	pos = mgmt->u.probe_req.variable;
1543 	if (pos[0] != WLAN_EID_SSID ||
1544 	    pos + 2 + pos[1] > end) {
1545 		ibss_dbg(sdata, "Invalid SSID IE in ProbeReq from %pM\n",
1546 			 mgmt->sa);
1547 		return;
1548 	}
1549 	if (pos[1] != 0 &&
1550 	    (pos[1] != ifibss->ssid_len ||
1551 	     memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
1552 		/* Ignore ProbeReq for foreign SSID */
1553 		return;
1554 	}
1555 
1556 	/* Reply with ProbeResp */
1557 	skb = dev_alloc_skb(local->tx_headroom + presp->head_len);
1558 	if (!skb)
1559 		return;
1560 
1561 	skb_reserve(skb, local->tx_headroom);
1562 	memcpy(skb_put(skb, presp->head_len), presp->head, presp->head_len);
1563 
1564 	memcpy(((struct ieee80211_mgmt *) skb->data)->da, mgmt->sa, ETH_ALEN);
1565 	ibss_dbg(sdata, "Sending ProbeResp to %pM\n", mgmt->sa);
1566 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
1567 
1568 	/* avoid excessive retries for probe request to wildcard SSIDs */
1569 	if (pos[1] == 0)
1570 		IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_NO_ACK;
1571 
1572 	ieee80211_tx_skb(sdata, skb);
1573 }
1574 
1575 static
1576 void ieee80211_rx_mgmt_probe_beacon(struct ieee80211_sub_if_data *sdata,
1577 				    struct ieee80211_mgmt *mgmt, size_t len,
1578 				    struct ieee80211_rx_status *rx_status)
1579 {
1580 	size_t baselen;
1581 	struct ieee802_11_elems elems;
1582 
1583 	BUILD_BUG_ON(offsetof(typeof(mgmt->u.probe_resp), variable) !=
1584 		     offsetof(typeof(mgmt->u.beacon), variable));
1585 
1586 	/*
1587 	 * either beacon or probe_resp but the variable field is at the
1588 	 * same offset
1589 	 */
1590 	baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
1591 	if (baselen > len)
1592 		return;
1593 
1594 	ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
1595 			       false, &elems);
1596 
1597 	ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems);
1598 }
1599 
1600 void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
1601 				   struct sk_buff *skb)
1602 {
1603 	struct ieee80211_rx_status *rx_status;
1604 	struct ieee80211_mgmt *mgmt;
1605 	u16 fc;
1606 	struct ieee802_11_elems elems;
1607 	int ies_len;
1608 
1609 	rx_status = IEEE80211_SKB_RXCB(skb);
1610 	mgmt = (struct ieee80211_mgmt *) skb->data;
1611 	fc = le16_to_cpu(mgmt->frame_control);
1612 
1613 	sdata_lock(sdata);
1614 
1615 	if (!sdata->u.ibss.ssid_len)
1616 		goto mgmt_out; /* not ready to merge yet */
1617 
1618 	switch (fc & IEEE80211_FCTL_STYPE) {
1619 	case IEEE80211_STYPE_PROBE_REQ:
1620 		ieee80211_rx_mgmt_probe_req(sdata, skb);
1621 		break;
1622 	case IEEE80211_STYPE_PROBE_RESP:
1623 	case IEEE80211_STYPE_BEACON:
1624 		ieee80211_rx_mgmt_probe_beacon(sdata, mgmt, skb->len,
1625 					       rx_status);
1626 		break;
1627 	case IEEE80211_STYPE_AUTH:
1628 		ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
1629 		break;
1630 	case IEEE80211_STYPE_DEAUTH:
1631 		ieee80211_rx_mgmt_deauth_ibss(sdata, mgmt, skb->len);
1632 		break;
1633 	case IEEE80211_STYPE_ACTION:
1634 		switch (mgmt->u.action.category) {
1635 		case WLAN_CATEGORY_SPECTRUM_MGMT:
1636 			ies_len = skb->len -
1637 				  offsetof(struct ieee80211_mgmt,
1638 					   u.action.u.chan_switch.variable);
1639 
1640 			if (ies_len < 0)
1641 				break;
1642 
1643 			ieee802_11_parse_elems(
1644 				mgmt->u.action.u.chan_switch.variable,
1645 				ies_len, true, &elems);
1646 
1647 			if (elems.parse_error)
1648 				break;
1649 
1650 			ieee80211_rx_mgmt_spectrum_mgmt(sdata, mgmt, skb->len,
1651 							rx_status, &elems);
1652 			break;
1653 		}
1654 	}
1655 
1656  mgmt_out:
1657 	sdata_unlock(sdata);
1658 }
1659 
1660 void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
1661 {
1662 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1663 	struct sta_info *sta;
1664 
1665 	sdata_lock(sdata);
1666 
1667 	/*
1668 	 * Work could be scheduled after scan or similar
1669 	 * when we aren't even joined (or trying) with a
1670 	 * network.
1671 	 */
1672 	if (!ifibss->ssid_len)
1673 		goto out;
1674 
1675 	spin_lock_bh(&ifibss->incomplete_lock);
1676 	while (!list_empty(&ifibss->incomplete_stations)) {
1677 		sta = list_first_entry(&ifibss->incomplete_stations,
1678 				       struct sta_info, list);
1679 		list_del(&sta->list);
1680 		spin_unlock_bh(&ifibss->incomplete_lock);
1681 
1682 		ieee80211_ibss_finish_sta(sta);
1683 		rcu_read_unlock();
1684 		spin_lock_bh(&ifibss->incomplete_lock);
1685 	}
1686 	spin_unlock_bh(&ifibss->incomplete_lock);
1687 
1688 	switch (ifibss->state) {
1689 	case IEEE80211_IBSS_MLME_SEARCH:
1690 		ieee80211_sta_find_ibss(sdata);
1691 		break;
1692 	case IEEE80211_IBSS_MLME_JOINED:
1693 		ieee80211_sta_merge_ibss(sdata);
1694 		break;
1695 	default:
1696 		WARN_ON(1);
1697 		break;
1698 	}
1699 
1700  out:
1701 	sdata_unlock(sdata);
1702 }
1703 
1704 static void ieee80211_ibss_timer(unsigned long data)
1705 {
1706 	struct ieee80211_sub_if_data *sdata =
1707 		(struct ieee80211_sub_if_data *) data;
1708 
1709 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
1710 }
1711 
1712 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
1713 {
1714 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1715 
1716 	setup_timer(&ifibss->timer, ieee80211_ibss_timer,
1717 		    (unsigned long) sdata);
1718 	INIT_LIST_HEAD(&ifibss->incomplete_stations);
1719 	spin_lock_init(&ifibss->incomplete_lock);
1720 	INIT_WORK(&ifibss->csa_connection_drop_work,
1721 		  ieee80211_csa_connection_drop_work);
1722 }
1723 
1724 /* scan finished notification */
1725 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
1726 {
1727 	struct ieee80211_sub_if_data *sdata;
1728 
1729 	mutex_lock(&local->iflist_mtx);
1730 	list_for_each_entry(sdata, &local->interfaces, list) {
1731 		if (!ieee80211_sdata_running(sdata))
1732 			continue;
1733 		if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
1734 			continue;
1735 		sdata->u.ibss.last_scan_completed = jiffies;
1736 	}
1737 	mutex_unlock(&local->iflist_mtx);
1738 }
1739 
1740 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
1741 			struct cfg80211_ibss_params *params)
1742 {
1743 	u32 changed = 0;
1744 	u32 rate_flags;
1745 	struct ieee80211_supported_band *sband;
1746 	enum ieee80211_chanctx_mode chanmode;
1747 	struct ieee80211_local *local = sdata->local;
1748 	int radar_detect_width = 0;
1749 	int i;
1750 	int ret;
1751 
1752 	ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
1753 					    &params->chandef,
1754 					    sdata->wdev.iftype);
1755 	if (ret < 0)
1756 		return ret;
1757 
1758 	if (ret > 0) {
1759 		if (!params->userspace_handles_dfs)
1760 			return -EINVAL;
1761 		radar_detect_width = BIT(params->chandef.width);
1762 	}
1763 
1764 	chanmode = (params->channel_fixed && !ret) ?
1765 		IEEE80211_CHANCTX_SHARED : IEEE80211_CHANCTX_EXCLUSIVE;
1766 
1767 	mutex_lock(&local->chanctx_mtx);
1768 	ret = ieee80211_check_combinations(sdata, &params->chandef, chanmode,
1769 					   radar_detect_width);
1770 	mutex_unlock(&local->chanctx_mtx);
1771 	if (ret < 0)
1772 		return ret;
1773 
1774 	if (params->bssid) {
1775 		memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
1776 		sdata->u.ibss.fixed_bssid = true;
1777 	} else
1778 		sdata->u.ibss.fixed_bssid = false;
1779 
1780 	sdata->u.ibss.privacy = params->privacy;
1781 	sdata->u.ibss.control_port = params->control_port;
1782 	sdata->u.ibss.userspace_handles_dfs = params->userspace_handles_dfs;
1783 	sdata->u.ibss.basic_rates = params->basic_rates;
1784 	sdata->u.ibss.last_scan_completed = jiffies;
1785 
1786 	/* fix basic_rates if channel does not support these rates */
1787 	rate_flags = ieee80211_chandef_rate_flags(&params->chandef);
1788 	sband = local->hw.wiphy->bands[params->chandef.chan->band];
1789 	for (i = 0; i < sband->n_bitrates; i++) {
1790 		if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
1791 			sdata->u.ibss.basic_rates &= ~BIT(i);
1792 	}
1793 	memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate,
1794 	       sizeof(params->mcast_rate));
1795 
1796 	sdata->vif.bss_conf.beacon_int = params->beacon_interval;
1797 
1798 	sdata->u.ibss.chandef = params->chandef;
1799 	sdata->u.ibss.fixed_channel = params->channel_fixed;
1800 
1801 	if (params->ie) {
1802 		sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
1803 					   GFP_KERNEL);
1804 		if (sdata->u.ibss.ie)
1805 			sdata->u.ibss.ie_len = params->ie_len;
1806 	}
1807 
1808 	sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
1809 	sdata->u.ibss.ibss_join_req = jiffies;
1810 
1811 	memcpy(sdata->u.ibss.ssid, params->ssid, params->ssid_len);
1812 	sdata->u.ibss.ssid_len = params->ssid_len;
1813 
1814 	memcpy(&sdata->u.ibss.ht_capa, &params->ht_capa,
1815 	       sizeof(sdata->u.ibss.ht_capa));
1816 	memcpy(&sdata->u.ibss.ht_capa_mask, &params->ht_capa_mask,
1817 	       sizeof(sdata->u.ibss.ht_capa_mask));
1818 
1819 	/*
1820 	 * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is
1821 	 * reserved, but an HT STA shall protect HT transmissions as though
1822 	 * the HT Protection field were set to non-HT mixed mode.
1823 	 *
1824 	 * In an IBSS, the RIFS Mode field of the HT Operation element is
1825 	 * also reserved, but an HT STA shall operate as though this field
1826 	 * were set to 1.
1827 	 */
1828 
1829 	sdata->vif.bss_conf.ht_operation_mode |=
1830 		  IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED
1831 		| IEEE80211_HT_PARAM_RIFS_MODE;
1832 
1833 	changed |= BSS_CHANGED_HT;
1834 	ieee80211_bss_info_change_notify(sdata, changed);
1835 
1836 	sdata->smps_mode = IEEE80211_SMPS_OFF;
1837 	sdata->needed_rx_chains = local->rx_chains;
1838 
1839 	ieee80211_queue_work(&local->hw, &sdata->work);
1840 
1841 	return 0;
1842 }
1843 
1844 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
1845 {
1846 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1847 
1848 	ieee80211_ibss_disconnect(sdata);
1849 	ifibss->ssid_len = 0;
1850 	eth_zero_addr(ifibss->bssid);
1851 
1852 	/* remove beacon */
1853 	kfree(sdata->u.ibss.ie);
1854 
1855 	/* on the next join, re-program HT parameters */
1856 	memset(&ifibss->ht_capa, 0, sizeof(ifibss->ht_capa));
1857 	memset(&ifibss->ht_capa_mask, 0, sizeof(ifibss->ht_capa_mask));
1858 
1859 	synchronize_rcu();
1860 
1861 	skb_queue_purge(&sdata->skb_queue);
1862 
1863 	del_timer_sync(&sdata->u.ibss.timer);
1864 
1865 	return 0;
1866 }
1867