xref: /openbmc/linux/net/mac80211/ibss.c (revision 6d8e62c3)
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 	}
150 
151 	/* put the remaining rates in WLAN_EID_EXT_SUPP_RATES */
152 	if (rates_n > 8) {
153 		*pos++ = WLAN_EID_EXT_SUPP_RATES;
154 		*pos++ = rates_n - 8;
155 		for (; ri < sband->n_bitrates; ri++) {
156 			int rate = DIV_ROUND_UP(sband->bitrates[ri].bitrate,
157 						5 * (1 << shift));
158 			u8 basic = 0;
159 			if (!(rates & BIT(ri)))
160 				continue;
161 
162 			if (basic_rates & BIT(ri))
163 				basic = 0x80;
164 			*pos++ = basic | (u8) rate;
165 		}
166 	}
167 
168 	if (ifibss->ie_len) {
169 		memcpy(pos, ifibss->ie, ifibss->ie_len);
170 		pos += ifibss->ie_len;
171 	}
172 
173 	/* add HT capability and information IEs */
174 	if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT &&
175 	    chandef->width != NL80211_CHAN_WIDTH_5 &&
176 	    chandef->width != NL80211_CHAN_WIDTH_10 &&
177 	    sband->ht_cap.ht_supported) {
178 		struct ieee80211_sta_ht_cap ht_cap;
179 
180 		memcpy(&ht_cap, &sband->ht_cap, sizeof(ht_cap));
181 		ieee80211_apply_htcap_overrides(sdata, &ht_cap);
182 
183 		pos = ieee80211_ie_build_ht_cap(pos, &ht_cap, ht_cap.cap);
184 		/*
185 		 * Note: According to 802.11n-2009 9.13.3.1, HT Protection
186 		 * field and RIFS Mode are reserved in IBSS mode, therefore
187 		 * keep them at 0
188 		 */
189 		pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap,
190 						 chandef, 0);
191 	}
192 
193 	if (local->hw.queues >= IEEE80211_NUM_ACS)
194 		pos = ieee80211_add_wmm_info_ie(pos, 0); /* U-APSD not in use */
195 
196 	presp->head_len = pos - presp->head;
197 	if (WARN_ON(presp->head_len > frame_len))
198 		goto error;
199 
200 	return presp;
201 error:
202 	kfree(presp);
203 	return NULL;
204 }
205 
206 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
207 				      const u8 *bssid, const int beacon_int,
208 				      struct cfg80211_chan_def *req_chandef,
209 				      const u32 basic_rates,
210 				      const u16 capability, u64 tsf,
211 				      bool creator)
212 {
213 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
214 	struct ieee80211_local *local = sdata->local;
215 	struct ieee80211_mgmt *mgmt;
216 	struct cfg80211_bss *bss;
217 	u32 bss_change;
218 	struct cfg80211_chan_def chandef;
219 	struct ieee80211_channel *chan;
220 	struct beacon_data *presp;
221 	enum nl80211_bss_scan_width scan_width;
222 	bool have_higher_than_11mbit;
223 	bool radar_required;
224 	int err;
225 
226 	sdata_assert_lock(sdata);
227 
228 	/* Reset own TSF to allow time synchronization work. */
229 	drv_reset_tsf(local, sdata);
230 
231 	if (!ether_addr_equal(ifibss->bssid, bssid))
232 		sta_info_flush(sdata);
233 
234 	/* if merging, indicate to driver that we leave the old IBSS */
235 	if (sdata->vif.bss_conf.ibss_joined) {
236 		sdata->vif.bss_conf.ibss_joined = false;
237 		sdata->vif.bss_conf.ibss_creator = false;
238 		sdata->vif.bss_conf.enable_beacon = false;
239 		netif_carrier_off(sdata->dev);
240 		ieee80211_bss_info_change_notify(sdata,
241 						 BSS_CHANGED_IBSS |
242 						 BSS_CHANGED_BEACON_ENABLED);
243 		drv_leave_ibss(local, sdata);
244 	}
245 
246 	presp = rcu_dereference_protected(ifibss->presp,
247 					  lockdep_is_held(&sdata->wdev.mtx));
248 	RCU_INIT_POINTER(ifibss->presp, NULL);
249 	if (presp)
250 		kfree_rcu(presp, rcu_head);
251 
252 	sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
253 
254 	/* make a copy of the chandef, it could be modified below. */
255 	chandef = *req_chandef;
256 	chan = chandef.chan;
257 	if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef,
258 				     NL80211_IFTYPE_ADHOC)) {
259 		if (chandef.width == NL80211_CHAN_WIDTH_5 ||
260 		    chandef.width == NL80211_CHAN_WIDTH_10 ||
261 		    chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
262 		    chandef.width == NL80211_CHAN_WIDTH_20) {
263 			sdata_info(sdata,
264 				   "Failed to join IBSS, beacons forbidden\n");
265 			return;
266 		}
267 		chandef.width = NL80211_CHAN_WIDTH_20;
268 		chandef.center_freq1 = chan->center_freq;
269 		/* check again for downgraded chandef */
270 		if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef,
271 					     NL80211_IFTYPE_ADHOC)) {
272 			sdata_info(sdata,
273 				   "Failed to join IBSS, beacons forbidden\n");
274 			return;
275 		}
276 	}
277 
278 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
279 					    &chandef, NL80211_IFTYPE_ADHOC);
280 	if (err < 0) {
281 		sdata_info(sdata,
282 			   "Failed to join IBSS, invalid chandef\n");
283 		return;
284 	}
285 	if (err > 0 && !ifibss->userspace_handles_dfs) {
286 		sdata_info(sdata,
287 			   "Failed to join IBSS, DFS channel without control program\n");
288 		return;
289 	}
290 
291 	radar_required = err;
292 
293 	mutex_lock(&local->mtx);
294 	if (ieee80211_vif_use_channel(sdata, &chandef,
295 				      ifibss->fixed_channel ?
296 					IEEE80211_CHANCTX_SHARED :
297 					IEEE80211_CHANCTX_EXCLUSIVE)) {
298 		sdata_info(sdata, "Failed to join IBSS, no channel context\n");
299 		mutex_unlock(&local->mtx);
300 		return;
301 	}
302 	sdata->radar_required = radar_required;
303 	mutex_unlock(&local->mtx);
304 
305 	memcpy(ifibss->bssid, bssid, ETH_ALEN);
306 
307 	presp = ieee80211_ibss_build_presp(sdata, beacon_int, basic_rates,
308 					   capability, tsf, &chandef,
309 					   &have_higher_than_11mbit, NULL);
310 	if (!presp)
311 		return;
312 
313 	rcu_assign_pointer(ifibss->presp, presp);
314 	mgmt = (void *)presp->head;
315 
316 	sdata->vif.bss_conf.enable_beacon = true;
317 	sdata->vif.bss_conf.beacon_int = beacon_int;
318 	sdata->vif.bss_conf.basic_rates = basic_rates;
319 	sdata->vif.bss_conf.ssid_len = ifibss->ssid_len;
320 	memcpy(sdata->vif.bss_conf.ssid, ifibss->ssid, ifibss->ssid_len);
321 	bss_change = BSS_CHANGED_BEACON_INT;
322 	bss_change |= ieee80211_reset_erp_info(sdata);
323 	bss_change |= BSS_CHANGED_BSSID;
324 	bss_change |= BSS_CHANGED_BEACON;
325 	bss_change |= BSS_CHANGED_BEACON_ENABLED;
326 	bss_change |= BSS_CHANGED_BASIC_RATES;
327 	bss_change |= BSS_CHANGED_HT;
328 	bss_change |= BSS_CHANGED_IBSS;
329 	bss_change |= BSS_CHANGED_SSID;
330 
331 	/*
332 	 * In 5 GHz/802.11a, we can always use short slot time.
333 	 * (IEEE 802.11-2012 18.3.8.7)
334 	 *
335 	 * In 2.4GHz, we must always use long slots in IBSS for compatibility
336 	 * reasons.
337 	 * (IEEE 802.11-2012 19.4.5)
338 	 *
339 	 * HT follows these specifications (IEEE 802.11-2012 20.3.18)
340 	 */
341 	sdata->vif.bss_conf.use_short_slot = chan->band == IEEE80211_BAND_5GHZ;
342 	bss_change |= BSS_CHANGED_ERP_SLOT;
343 
344 	/* cf. IEEE 802.11 9.2.12 */
345 	if (chan->band == IEEE80211_BAND_2GHZ && have_higher_than_11mbit)
346 		sdata->flags |= IEEE80211_SDATA_OPERATING_GMODE;
347 	else
348 		sdata->flags &= ~IEEE80211_SDATA_OPERATING_GMODE;
349 
350 	ieee80211_set_wmm_default(sdata, true);
351 
352 	sdata->vif.bss_conf.ibss_joined = true;
353 	sdata->vif.bss_conf.ibss_creator = creator;
354 
355 	err = drv_join_ibss(local, sdata);
356 	if (err) {
357 		sdata->vif.bss_conf.ibss_joined = false;
358 		sdata->vif.bss_conf.ibss_creator = false;
359 		sdata->vif.bss_conf.enable_beacon = false;
360 		sdata->vif.bss_conf.ssid_len = 0;
361 		RCU_INIT_POINTER(ifibss->presp, NULL);
362 		kfree_rcu(presp, rcu_head);
363 		mutex_lock(&local->mtx);
364 		ieee80211_vif_release_channel(sdata);
365 		mutex_unlock(&local->mtx);
366 		sdata_info(sdata, "Failed to join IBSS, driver failure: %d\n",
367 			   err);
368 		return;
369 	}
370 
371 	ieee80211_bss_info_change_notify(sdata, bss_change);
372 
373 	ifibss->state = IEEE80211_IBSS_MLME_JOINED;
374 	mod_timer(&ifibss->timer,
375 		  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
376 
377 	scan_width = cfg80211_chandef_to_scan_width(&chandef);
378 	bss = cfg80211_inform_bss_width_frame(local->hw.wiphy, chan,
379 					      scan_width, mgmt,
380 					      presp->head_len, 0, GFP_KERNEL);
381 	cfg80211_put_bss(local->hw.wiphy, bss);
382 	netif_carrier_on(sdata->dev);
383 	cfg80211_ibss_joined(sdata->dev, ifibss->bssid, chan, GFP_KERNEL);
384 }
385 
386 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
387 				    struct ieee80211_bss *bss)
388 {
389 	struct cfg80211_bss *cbss =
390 		container_of((void *)bss, struct cfg80211_bss, priv);
391 	struct ieee80211_supported_band *sband;
392 	struct cfg80211_chan_def chandef;
393 	u32 basic_rates;
394 	int i, j;
395 	u16 beacon_int = cbss->beacon_interval;
396 	const struct cfg80211_bss_ies *ies;
397 	enum nl80211_channel_type chan_type;
398 	u64 tsf;
399 	u32 rate_flags;
400 	int shift;
401 
402 	sdata_assert_lock(sdata);
403 
404 	if (beacon_int < 10)
405 		beacon_int = 10;
406 
407 	switch (sdata->u.ibss.chandef.width) {
408 	case NL80211_CHAN_WIDTH_20_NOHT:
409 	case NL80211_CHAN_WIDTH_20:
410 	case NL80211_CHAN_WIDTH_40:
411 		chan_type = cfg80211_get_chandef_type(&sdata->u.ibss.chandef);
412 		cfg80211_chandef_create(&chandef, cbss->channel, chan_type);
413 		break;
414 	case NL80211_CHAN_WIDTH_5:
415 	case NL80211_CHAN_WIDTH_10:
416 		cfg80211_chandef_create(&chandef, cbss->channel,
417 					NL80211_CHAN_WIDTH_20_NOHT);
418 		chandef.width = sdata->u.ibss.chandef.width;
419 		break;
420 	default:
421 		/* fall back to 20 MHz for unsupported modes */
422 		cfg80211_chandef_create(&chandef, cbss->channel,
423 					NL80211_CHAN_WIDTH_20_NOHT);
424 		break;
425 	}
426 
427 	sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
428 	rate_flags = ieee80211_chandef_rate_flags(&sdata->u.ibss.chandef);
429 	shift = ieee80211_vif_get_shift(&sdata->vif);
430 
431 	basic_rates = 0;
432 
433 	for (i = 0; i < bss->supp_rates_len; i++) {
434 		int rate = bss->supp_rates[i] & 0x7f;
435 		bool is_basic = !!(bss->supp_rates[i] & 0x80);
436 
437 		for (j = 0; j < sband->n_bitrates; j++) {
438 			int brate;
439 			if ((rate_flags & sband->bitrates[j].flags)
440 			    != rate_flags)
441 				continue;
442 
443 			brate = DIV_ROUND_UP(sband->bitrates[j].bitrate,
444 					     5 * (1 << shift));
445 			if (brate == rate) {
446 				if (is_basic)
447 					basic_rates |= BIT(j);
448 				break;
449 			}
450 		}
451 	}
452 
453 	rcu_read_lock();
454 	ies = rcu_dereference(cbss->ies);
455 	tsf = ies->tsf;
456 	rcu_read_unlock();
457 
458 	__ieee80211_sta_join_ibss(sdata, cbss->bssid,
459 				  beacon_int,
460 				  &chandef,
461 				  basic_rates,
462 				  cbss->capability,
463 				  tsf, false);
464 }
465 
466 int ieee80211_ibss_csa_beacon(struct ieee80211_sub_if_data *sdata,
467 			      struct cfg80211_csa_settings *csa_settings)
468 {
469 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
470 	struct beacon_data *presp, *old_presp;
471 	struct cfg80211_bss *cbss;
472 	const struct cfg80211_bss_ies *ies;
473 	u16 capability;
474 	u64 tsf;
475 	int ret = 0;
476 
477 	sdata_assert_lock(sdata);
478 
479 	capability = WLAN_CAPABILITY_IBSS;
480 
481 	if (ifibss->privacy)
482 		capability |= WLAN_CAPABILITY_PRIVACY;
483 
484 	cbss = cfg80211_get_bss(sdata->local->hw.wiphy, ifibss->chandef.chan,
485 				ifibss->bssid, ifibss->ssid,
486 				ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
487 				WLAN_CAPABILITY_PRIVACY,
488 				capability);
489 
490 	if (WARN_ON(!cbss)) {
491 		ret = -EINVAL;
492 		goto out;
493 	}
494 
495 	rcu_read_lock();
496 	ies = rcu_dereference(cbss->ies);
497 	tsf = ies->tsf;
498 	rcu_read_unlock();
499 	cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
500 
501 	old_presp = rcu_dereference_protected(ifibss->presp,
502 					  lockdep_is_held(&sdata->wdev.mtx));
503 
504 	presp = ieee80211_ibss_build_presp(sdata,
505 					   sdata->vif.bss_conf.beacon_int,
506 					   sdata->vif.bss_conf.basic_rates,
507 					   capability, tsf, &ifibss->chandef,
508 					   NULL, csa_settings);
509 	if (!presp) {
510 		ret = -ENOMEM;
511 		goto out;
512 	}
513 
514 	rcu_assign_pointer(ifibss->presp, presp);
515 	if (old_presp)
516 		kfree_rcu(old_presp, rcu_head);
517 
518 	return BSS_CHANGED_BEACON;
519  out:
520 	return ret;
521 }
522 
523 int ieee80211_ibss_finish_csa(struct ieee80211_sub_if_data *sdata)
524 {
525 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
526 	struct cfg80211_bss *cbss;
527 	int err, changed = 0;
528 	u16 capability;
529 
530 	sdata_assert_lock(sdata);
531 
532 	/* update cfg80211 bss information with the new channel */
533 	if (!is_zero_ether_addr(ifibss->bssid)) {
534 		capability = WLAN_CAPABILITY_IBSS;
535 
536 		if (ifibss->privacy)
537 			capability |= WLAN_CAPABILITY_PRIVACY;
538 
539 		cbss = cfg80211_get_bss(sdata->local->hw.wiphy,
540 					ifibss->chandef.chan,
541 					ifibss->bssid, ifibss->ssid,
542 					ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
543 					WLAN_CAPABILITY_PRIVACY,
544 					capability);
545 		/* XXX: should not really modify cfg80211 data */
546 		if (cbss) {
547 			cbss->channel = sdata->csa_chandef.chan;
548 			cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
549 		}
550 	}
551 
552 	ifibss->chandef = sdata->csa_chandef;
553 
554 	/* generate the beacon */
555 	err = ieee80211_ibss_csa_beacon(sdata, NULL);
556 	if (err < 0)
557 		return err;
558 
559 	changed |= err;
560 
561 	return changed;
562 }
563 
564 void ieee80211_ibss_stop(struct ieee80211_sub_if_data *sdata)
565 {
566 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
567 
568 	cancel_work_sync(&ifibss->csa_connection_drop_work);
569 }
570 
571 static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta)
572 	__acquires(RCU)
573 {
574 	struct ieee80211_sub_if_data *sdata = sta->sdata;
575 	u8 addr[ETH_ALEN];
576 
577 	memcpy(addr, sta->sta.addr, ETH_ALEN);
578 
579 	ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr);
580 
581 	sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
582 	sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
583 	/* authorize the station only if the network is not RSN protected. If
584 	 * not wait for the userspace to authorize it */
585 	if (!sta->sdata->u.ibss.control_port)
586 		sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
587 
588 	rate_control_rate_init(sta);
589 
590 	/* If it fails, maybe we raced another insertion? */
591 	if (sta_info_insert_rcu(sta))
592 		return sta_info_get(sdata, addr);
593 	return sta;
594 }
595 
596 static struct sta_info *
597 ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, const u8 *bssid,
598 		       const u8 *addr, u32 supp_rates)
599 	__acquires(RCU)
600 {
601 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
602 	struct ieee80211_local *local = sdata->local;
603 	struct sta_info *sta;
604 	struct ieee80211_chanctx_conf *chanctx_conf;
605 	struct ieee80211_supported_band *sband;
606 	enum nl80211_bss_scan_width scan_width;
607 	int band;
608 
609 	/*
610 	 * XXX: Consider removing the least recently used entry and
611 	 * 	allow new one to be added.
612 	 */
613 	if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
614 		net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
615 				    sdata->name, addr);
616 		rcu_read_lock();
617 		return NULL;
618 	}
619 
620 	if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) {
621 		rcu_read_lock();
622 		return NULL;
623 	}
624 
625 	if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) {
626 		rcu_read_lock();
627 		return NULL;
628 	}
629 
630 	rcu_read_lock();
631 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
632 	if (WARN_ON_ONCE(!chanctx_conf))
633 		return NULL;
634 	band = chanctx_conf->def.chan->band;
635 	scan_width = cfg80211_chandef_to_scan_width(&chanctx_conf->def);
636 	rcu_read_unlock();
637 
638 	sta = sta_info_alloc(sdata, addr, GFP_KERNEL);
639 	if (!sta) {
640 		rcu_read_lock();
641 		return NULL;
642 	}
643 
644 	sta->last_rx = jiffies;
645 
646 	/* make sure mandatory rates are always added */
647 	sband = local->hw.wiphy->bands[band];
648 	sta->sta.supp_rates[band] = supp_rates |
649 			ieee80211_mandatory_rates(sband, scan_width);
650 
651 	return ieee80211_ibss_finish_sta(sta);
652 }
653 
654 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
655 {
656 	struct ieee80211_local *local = sdata->local;
657 	int active = 0;
658 	struct sta_info *sta;
659 
660 	sdata_assert_lock(sdata);
661 
662 	rcu_read_lock();
663 
664 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
665 		if (sta->sdata == sdata &&
666 		    time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
667 			       jiffies)) {
668 			active++;
669 			break;
670 		}
671 	}
672 
673 	rcu_read_unlock();
674 
675 	return active;
676 }
677 
678 static void ieee80211_ibss_disconnect(struct ieee80211_sub_if_data *sdata)
679 {
680 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
681 	struct ieee80211_local *local = sdata->local;
682 	struct cfg80211_bss *cbss;
683 	struct beacon_data *presp;
684 	struct sta_info *sta;
685 	u16 capability;
686 
687 	if (!is_zero_ether_addr(ifibss->bssid)) {
688 		capability = WLAN_CAPABILITY_IBSS;
689 
690 		if (ifibss->privacy)
691 			capability |= WLAN_CAPABILITY_PRIVACY;
692 
693 		cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->chandef.chan,
694 					ifibss->bssid, ifibss->ssid,
695 					ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
696 					WLAN_CAPABILITY_PRIVACY,
697 					capability);
698 
699 		if (cbss) {
700 			cfg80211_unlink_bss(local->hw.wiphy, cbss);
701 			cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
702 		}
703 	}
704 
705 	ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
706 
707 	sta_info_flush(sdata);
708 
709 	spin_lock_bh(&ifibss->incomplete_lock);
710 	while (!list_empty(&ifibss->incomplete_stations)) {
711 		sta = list_first_entry(&ifibss->incomplete_stations,
712 				       struct sta_info, list);
713 		list_del(&sta->list);
714 		spin_unlock_bh(&ifibss->incomplete_lock);
715 
716 		sta_info_free(local, sta);
717 		spin_lock_bh(&ifibss->incomplete_lock);
718 	}
719 	spin_unlock_bh(&ifibss->incomplete_lock);
720 
721 	netif_carrier_off(sdata->dev);
722 
723 	sdata->vif.bss_conf.ibss_joined = false;
724 	sdata->vif.bss_conf.ibss_creator = false;
725 	sdata->vif.bss_conf.enable_beacon = false;
726 	sdata->vif.bss_conf.ssid_len = 0;
727 
728 	/* remove beacon */
729 	presp = rcu_dereference_protected(ifibss->presp,
730 					  lockdep_is_held(&sdata->wdev.mtx));
731 	RCU_INIT_POINTER(sdata->u.ibss.presp, NULL);
732 	if (presp)
733 		kfree_rcu(presp, rcu_head);
734 
735 	clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
736 	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
737 						BSS_CHANGED_IBSS);
738 	drv_leave_ibss(local, sdata);
739 	mutex_lock(&local->mtx);
740 	ieee80211_vif_release_channel(sdata);
741 	mutex_unlock(&local->mtx);
742 }
743 
744 static void ieee80211_csa_connection_drop_work(struct work_struct *work)
745 {
746 	struct ieee80211_sub_if_data *sdata =
747 		container_of(work, struct ieee80211_sub_if_data,
748 			     u.ibss.csa_connection_drop_work);
749 
750 	sdata_lock(sdata);
751 
752 	ieee80211_ibss_disconnect(sdata);
753 	synchronize_rcu();
754 	skb_queue_purge(&sdata->skb_queue);
755 
756 	/* trigger a scan to find another IBSS network to join */
757 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
758 
759 	sdata_unlock(sdata);
760 }
761 
762 static void ieee80211_ibss_csa_mark_radar(struct ieee80211_sub_if_data *sdata)
763 {
764 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
765 	int err;
766 
767 	/* if the current channel is a DFS channel, mark the channel as
768 	 * unavailable.
769 	 */
770 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
771 					    &ifibss->chandef,
772 					    NL80211_IFTYPE_ADHOC);
773 	if (err > 0)
774 		cfg80211_radar_event(sdata->local->hw.wiphy, &ifibss->chandef,
775 				     GFP_ATOMIC);
776 }
777 
778 static bool
779 ieee80211_ibss_process_chanswitch(struct ieee80211_sub_if_data *sdata,
780 				  struct ieee802_11_elems *elems,
781 				  bool beacon)
782 {
783 	struct cfg80211_csa_settings params;
784 	struct ieee80211_csa_ie csa_ie;
785 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
786 	enum nl80211_channel_type ch_type;
787 	int err;
788 	u32 sta_flags;
789 
790 	sdata_assert_lock(sdata);
791 
792 	sta_flags = IEEE80211_STA_DISABLE_VHT;
793 	switch (ifibss->chandef.width) {
794 	case NL80211_CHAN_WIDTH_5:
795 	case NL80211_CHAN_WIDTH_10:
796 	case NL80211_CHAN_WIDTH_20_NOHT:
797 		sta_flags |= IEEE80211_STA_DISABLE_HT;
798 		/* fall through */
799 	case NL80211_CHAN_WIDTH_20:
800 		sta_flags |= IEEE80211_STA_DISABLE_40MHZ;
801 		break;
802 	default:
803 		break;
804 	}
805 
806 	memset(&params, 0, sizeof(params));
807 	memset(&csa_ie, 0, sizeof(csa_ie));
808 	err = ieee80211_parse_ch_switch_ie(sdata, elems,
809 					   ifibss->chandef.chan->band,
810 					   sta_flags, ifibss->bssid, &csa_ie);
811 	/* can't switch to destination channel, fail */
812 	if (err < 0)
813 		goto disconnect;
814 
815 	/* did not contain a CSA */
816 	if (err)
817 		return false;
818 
819 	/* channel switch is not supported, disconnect */
820 	if (!(sdata->local->hw.wiphy->flags & WIPHY_FLAG_HAS_CHANNEL_SWITCH))
821 		goto disconnect;
822 
823 	params.count = csa_ie.count;
824 	params.chandef = csa_ie.chandef;
825 
826 	switch (ifibss->chandef.width) {
827 	case NL80211_CHAN_WIDTH_20_NOHT:
828 	case NL80211_CHAN_WIDTH_20:
829 	case NL80211_CHAN_WIDTH_40:
830 		/* keep our current HT mode (HT20/HT40+/HT40-), even if
831 		 * another mode  has been announced. The mode is not adopted
832 		 * within the beacon while doing CSA and we should therefore
833 		 * keep the mode which we announce.
834 		 */
835 		ch_type = cfg80211_get_chandef_type(&ifibss->chandef);
836 		cfg80211_chandef_create(&params.chandef, params.chandef.chan,
837 					ch_type);
838 		break;
839 	case NL80211_CHAN_WIDTH_5:
840 	case NL80211_CHAN_WIDTH_10:
841 		if (params.chandef.width != ifibss->chandef.width) {
842 			sdata_info(sdata,
843 				   "IBSS %pM received channel switch from incompatible channel width (%d MHz, width:%d, CF1/2: %d/%d MHz), disconnecting\n",
844 				   ifibss->bssid,
845 				   params.chandef.chan->center_freq,
846 				   params.chandef.width,
847 				   params.chandef.center_freq1,
848 				   params.chandef.center_freq2);
849 			goto disconnect;
850 		}
851 		break;
852 	default:
853 		/* should not happen, sta_flags should prevent VHT modes. */
854 		WARN_ON(1);
855 		goto disconnect;
856 	}
857 
858 	if (!cfg80211_reg_can_beacon(sdata->local->hw.wiphy, &params.chandef,
859 				     NL80211_IFTYPE_ADHOC)) {
860 		sdata_info(sdata,
861 			   "IBSS %pM switches to unsupported channel (%d MHz, width:%d, CF1/2: %d/%d MHz), disconnecting\n",
862 			   ifibss->bssid,
863 			   params.chandef.chan->center_freq,
864 			   params.chandef.width,
865 			   params.chandef.center_freq1,
866 			   params.chandef.center_freq2);
867 		goto disconnect;
868 	}
869 
870 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
871 					    &params.chandef,
872 					    NL80211_IFTYPE_ADHOC);
873 	if (err < 0)
874 		goto disconnect;
875 	if (err > 0 && !ifibss->userspace_handles_dfs) {
876 		/* IBSS-DFS only allowed with a control program */
877 		goto disconnect;
878 	}
879 
880 	params.radar_required = err;
881 
882 	if (cfg80211_chandef_identical(&params.chandef,
883 				       &sdata->vif.bss_conf.chandef)) {
884 		ibss_dbg(sdata,
885 			 "received csa with an identical chandef, ignoring\n");
886 		return true;
887 	}
888 
889 	/* all checks done, now perform the channel switch. */
890 	ibss_dbg(sdata,
891 		 "received channel switch announcement to go to channel %d MHz\n",
892 		 params.chandef.chan->center_freq);
893 
894 	params.block_tx = !!csa_ie.mode;
895 
896 	if (ieee80211_channel_switch(sdata->local->hw.wiphy, sdata->dev,
897 				     &params))
898 		goto disconnect;
899 
900 	ieee80211_ibss_csa_mark_radar(sdata);
901 
902 	return true;
903 disconnect:
904 	ibss_dbg(sdata, "Can't handle channel switch, disconnect\n");
905 	ieee80211_queue_work(&sdata->local->hw,
906 			     &ifibss->csa_connection_drop_work);
907 
908 	ieee80211_ibss_csa_mark_radar(sdata);
909 
910 	return true;
911 }
912 
913 static void
914 ieee80211_rx_mgmt_spectrum_mgmt(struct ieee80211_sub_if_data *sdata,
915 				struct ieee80211_mgmt *mgmt, size_t len,
916 				struct ieee80211_rx_status *rx_status,
917 				struct ieee802_11_elems *elems)
918 {
919 	int required_len;
920 
921 	if (len < IEEE80211_MIN_ACTION_SIZE + 1)
922 		return;
923 
924 	/* CSA is the only action we handle for now */
925 	if (mgmt->u.action.u.measurement.action_code !=
926 	    WLAN_ACTION_SPCT_CHL_SWITCH)
927 		return;
928 
929 	required_len = IEEE80211_MIN_ACTION_SIZE +
930 		       sizeof(mgmt->u.action.u.chan_switch);
931 	if (len < required_len)
932 		return;
933 
934 	if (!sdata->vif.csa_active)
935 		ieee80211_ibss_process_chanswitch(sdata, elems, false);
936 }
937 
938 static void ieee80211_rx_mgmt_deauth_ibss(struct ieee80211_sub_if_data *sdata,
939 					  struct ieee80211_mgmt *mgmt,
940 					  size_t len)
941 {
942 	u16 reason = le16_to_cpu(mgmt->u.deauth.reason_code);
943 
944 	if (len < IEEE80211_DEAUTH_FRAME_LEN)
945 		return;
946 
947 	ibss_dbg(sdata, "RX DeAuth SA=%pM DA=%pM BSSID=%pM (reason: %d)\n",
948 		 mgmt->sa, mgmt->da, mgmt->bssid, reason);
949 	sta_info_destroy_addr(sdata, mgmt->sa);
950 }
951 
952 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
953 					struct ieee80211_mgmt *mgmt,
954 					size_t len)
955 {
956 	u16 auth_alg, auth_transaction;
957 
958 	sdata_assert_lock(sdata);
959 
960 	if (len < 24 + 6)
961 		return;
962 
963 	auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
964 	auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
965 
966 	ibss_dbg(sdata,
967 		 "RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n",
968 		 mgmt->sa, mgmt->da, mgmt->bssid, auth_transaction);
969 
970 	if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1)
971 		return;
972 
973 	/*
974 	 * IEEE 802.11 standard does not require authentication in IBSS
975 	 * networks and most implementations do not seem to use it.
976 	 * However, try to reply to authentication attempts if someone
977 	 * has actually implemented this.
978 	 */
979 	ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, 0, NULL, 0,
980 			    mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0, 0);
981 }
982 
983 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
984 				  struct ieee80211_mgmt *mgmt, size_t len,
985 				  struct ieee80211_rx_status *rx_status,
986 				  struct ieee802_11_elems *elems)
987 {
988 	struct ieee80211_local *local = sdata->local;
989 	struct cfg80211_bss *cbss;
990 	struct ieee80211_bss *bss;
991 	struct sta_info *sta;
992 	struct ieee80211_channel *channel;
993 	u64 beacon_timestamp, rx_timestamp;
994 	u32 supp_rates = 0;
995 	enum ieee80211_band band = rx_status->band;
996 	enum nl80211_bss_scan_width scan_width;
997 	struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
998 	bool rates_updated = false;
999 
1000 	channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
1001 	if (!channel)
1002 		return;
1003 
1004 	if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
1005 	    ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid)) {
1006 
1007 		rcu_read_lock();
1008 		sta = sta_info_get(sdata, mgmt->sa);
1009 
1010 		if (elems->supp_rates) {
1011 			supp_rates = ieee80211_sta_get_rates(sdata, elems,
1012 							     band, NULL);
1013 			if (sta) {
1014 				u32 prev_rates;
1015 
1016 				prev_rates = sta->sta.supp_rates[band];
1017 				/* make sure mandatory rates are always added */
1018 				scan_width = NL80211_BSS_CHAN_WIDTH_20;
1019 				if (rx_status->flag & RX_FLAG_5MHZ)
1020 					scan_width = NL80211_BSS_CHAN_WIDTH_5;
1021 				if (rx_status->flag & RX_FLAG_10MHZ)
1022 					scan_width = NL80211_BSS_CHAN_WIDTH_10;
1023 
1024 				sta->sta.supp_rates[band] = supp_rates |
1025 					ieee80211_mandatory_rates(sband,
1026 								  scan_width);
1027 				if (sta->sta.supp_rates[band] != prev_rates) {
1028 					ibss_dbg(sdata,
1029 						 "updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n",
1030 						 sta->sta.addr, prev_rates,
1031 						 sta->sta.supp_rates[band]);
1032 					rates_updated = true;
1033 				}
1034 			} else {
1035 				rcu_read_unlock();
1036 				sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
1037 						mgmt->sa, supp_rates);
1038 			}
1039 		}
1040 
1041 		if (sta && elems->wmm_info)
1042 			sta->sta.wme = true;
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 
1052 			ieee80211_ht_oper_to_chandef(channel,
1053 						     elems->ht_operation,
1054 						     &chandef);
1055 
1056 			memcpy(&htcap_ie, elems->ht_cap_elem, sizeof(htcap_ie));
1057 
1058 			/*
1059 			 * fall back to HT20 if we don't use or use
1060 			 * the other extension channel
1061 			 */
1062 			if (chandef.center_freq1 !=
1063 			    sdata->u.ibss.chandef.center_freq1)
1064 				htcap_ie.cap_info &=
1065 					cpu_to_le16(~IEEE80211_HT_CAP_SUP_WIDTH_20_40);
1066 
1067 			rates_updated |= ieee80211_ht_cap_ie_to_sta_ht_cap(
1068 						sdata, sband, &htcap_ie, sta);
1069 		}
1070 
1071 		if (sta && rates_updated) {
1072 			drv_sta_rc_update(local, sdata, &sta->sta,
1073 					  IEEE80211_RC_SUPP_RATES_CHANGED);
1074 			rate_control_rate_init(sta);
1075 		}
1076 
1077 		rcu_read_unlock();
1078 	}
1079 
1080 	bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
1081 					channel);
1082 	if (!bss)
1083 		return;
1084 
1085 	cbss = container_of((void *)bss, struct cfg80211_bss, priv);
1086 
1087 	/* same for beacon and probe response */
1088 	beacon_timestamp = le64_to_cpu(mgmt->u.beacon.timestamp);
1089 
1090 	/* check if we need to merge IBSS */
1091 
1092 	/* not an IBSS */
1093 	if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
1094 		goto put_bss;
1095 
1096 	/* different channel */
1097 	if (sdata->u.ibss.fixed_channel &&
1098 	    sdata->u.ibss.chandef.chan != cbss->channel)
1099 		goto put_bss;
1100 
1101 	/* different SSID */
1102 	if (elems->ssid_len != sdata->u.ibss.ssid_len ||
1103 	    memcmp(elems->ssid, sdata->u.ibss.ssid,
1104 				sdata->u.ibss.ssid_len))
1105 		goto put_bss;
1106 
1107 	/* process channel switch */
1108 	if (sdata->vif.csa_active ||
1109 	    ieee80211_ibss_process_chanswitch(sdata, elems, true))
1110 		goto put_bss;
1111 
1112 	/* same BSSID */
1113 	if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid))
1114 		goto put_bss;
1115 
1116 	/* we use a fixed BSSID */
1117 	if (sdata->u.ibss.fixed_bssid)
1118 		goto put_bss;
1119 
1120 	if (ieee80211_have_rx_timestamp(rx_status)) {
1121 		/* time when timestamp field was received */
1122 		rx_timestamp =
1123 			ieee80211_calculate_rx_timestamp(local, rx_status,
1124 							 len + FCS_LEN, 24);
1125 	} else {
1126 		/*
1127 		 * second best option: get current TSF
1128 		 * (will return -1 if not supported)
1129 		 */
1130 		rx_timestamp = drv_get_tsf(local, sdata);
1131 	}
1132 
1133 	ibss_dbg(sdata,
1134 		 "RX beacon SA=%pM BSSID=%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
1135 		 mgmt->sa, mgmt->bssid,
1136 		 (unsigned long long)rx_timestamp,
1137 		 (unsigned long long)beacon_timestamp,
1138 		 (unsigned long long)(rx_timestamp - beacon_timestamp),
1139 		 jiffies);
1140 
1141 	if (beacon_timestamp > rx_timestamp) {
1142 		ibss_dbg(sdata,
1143 			 "beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n",
1144 			 mgmt->bssid);
1145 		ieee80211_sta_join_ibss(sdata, bss);
1146 		supp_rates = ieee80211_sta_get_rates(sdata, elems, band, NULL);
1147 		ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
1148 				       supp_rates);
1149 		rcu_read_unlock();
1150 	}
1151 
1152  put_bss:
1153 	ieee80211_rx_bss_put(local, bss);
1154 }
1155 
1156 void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata,
1157 			      const u8 *bssid, const u8 *addr,
1158 			      u32 supp_rates)
1159 {
1160 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1161 	struct ieee80211_local *local = sdata->local;
1162 	struct sta_info *sta;
1163 	struct ieee80211_chanctx_conf *chanctx_conf;
1164 	struct ieee80211_supported_band *sband;
1165 	enum nl80211_bss_scan_width scan_width;
1166 	int band;
1167 
1168 	/*
1169 	 * XXX: Consider removing the least recently used entry and
1170 	 * 	allow new one to be added.
1171 	 */
1172 	if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
1173 		net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
1174 				    sdata->name, addr);
1175 		return;
1176 	}
1177 
1178 	if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
1179 		return;
1180 
1181 	if (!ether_addr_equal(bssid, sdata->u.ibss.bssid))
1182 		return;
1183 
1184 	rcu_read_lock();
1185 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
1186 	if (WARN_ON_ONCE(!chanctx_conf)) {
1187 		rcu_read_unlock();
1188 		return;
1189 	}
1190 	band = chanctx_conf->def.chan->band;
1191 	scan_width = cfg80211_chandef_to_scan_width(&chanctx_conf->def);
1192 	rcu_read_unlock();
1193 
1194 	sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
1195 	if (!sta)
1196 		return;
1197 
1198 	sta->last_rx = jiffies;
1199 
1200 	/* make sure mandatory rates are always added */
1201 	sband = local->hw.wiphy->bands[band];
1202 	sta->sta.supp_rates[band] = supp_rates |
1203 			ieee80211_mandatory_rates(sband, scan_width);
1204 
1205 	spin_lock(&ifibss->incomplete_lock);
1206 	list_add(&sta->list, &ifibss->incomplete_stations);
1207 	spin_unlock(&ifibss->incomplete_lock);
1208 	ieee80211_queue_work(&local->hw, &sdata->work);
1209 }
1210 
1211 static void ieee80211_ibss_sta_expire(struct ieee80211_sub_if_data *sdata)
1212 {
1213 	struct ieee80211_local *local = sdata->local;
1214 	struct sta_info *sta, *tmp;
1215 	unsigned long exp_time = IEEE80211_IBSS_INACTIVITY_LIMIT;
1216 	unsigned long exp_rsn_time = IEEE80211_IBSS_RSN_INACTIVITY_LIMIT;
1217 
1218 	mutex_lock(&local->sta_mtx);
1219 
1220 	list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
1221 		if (sdata != sta->sdata)
1222 			continue;
1223 
1224 		if (time_after(jiffies, sta->last_rx + exp_time) ||
1225 		    (time_after(jiffies, sta->last_rx + exp_rsn_time) &&
1226 		     sta->sta_state != IEEE80211_STA_AUTHORIZED)) {
1227 			sta_dbg(sta->sdata, "expiring inactive %sSTA %pM\n",
1228 				sta->sta_state != IEEE80211_STA_AUTHORIZED ?
1229 				"not authorized " : "", sta->sta.addr);
1230 
1231 			WARN_ON(__sta_info_destroy(sta));
1232 		}
1233 	}
1234 
1235 	mutex_unlock(&local->sta_mtx);
1236 }
1237 
1238 /*
1239  * This function is called with state == IEEE80211_IBSS_MLME_JOINED
1240  */
1241 
1242 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
1243 {
1244 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1245 	enum nl80211_bss_scan_width scan_width;
1246 
1247 	sdata_assert_lock(sdata);
1248 
1249 	mod_timer(&ifibss->timer,
1250 		  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
1251 
1252 	ieee80211_ibss_sta_expire(sdata);
1253 
1254 	if (time_before(jiffies, ifibss->last_scan_completed +
1255 		       IEEE80211_IBSS_MERGE_INTERVAL))
1256 		return;
1257 
1258 	if (ieee80211_sta_active_ibss(sdata))
1259 		return;
1260 
1261 	if (ifibss->fixed_channel)
1262 		return;
1263 
1264 	sdata_info(sdata,
1265 		   "No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n");
1266 
1267 	scan_width = cfg80211_chandef_to_scan_width(&ifibss->chandef);
1268 	ieee80211_request_ibss_scan(sdata, ifibss->ssid, ifibss->ssid_len,
1269 				    NULL, scan_width);
1270 }
1271 
1272 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
1273 {
1274 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1275 	u8 bssid[ETH_ALEN];
1276 	u16 capability;
1277 	int i;
1278 
1279 	sdata_assert_lock(sdata);
1280 
1281 	if (ifibss->fixed_bssid) {
1282 		memcpy(bssid, ifibss->bssid, ETH_ALEN);
1283 	} else {
1284 		/* Generate random, not broadcast, locally administered BSSID. Mix in
1285 		 * own MAC address to make sure that devices that do not have proper
1286 		 * random number generator get different BSSID. */
1287 		get_random_bytes(bssid, ETH_ALEN);
1288 		for (i = 0; i < ETH_ALEN; i++)
1289 			bssid[i] ^= sdata->vif.addr[i];
1290 		bssid[0] &= ~0x01;
1291 		bssid[0] |= 0x02;
1292 	}
1293 
1294 	sdata_info(sdata, "Creating new IBSS network, BSSID %pM\n", bssid);
1295 
1296 	capability = WLAN_CAPABILITY_IBSS;
1297 
1298 	if (ifibss->privacy)
1299 		capability |= WLAN_CAPABILITY_PRIVACY;
1300 	else
1301 		sdata->drop_unencrypted = 0;
1302 
1303 	__ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
1304 				  &ifibss->chandef, ifibss->basic_rates,
1305 				  capability, 0, true);
1306 }
1307 
1308 /*
1309  * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
1310  */
1311 
1312 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
1313 {
1314 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1315 	struct ieee80211_local *local = sdata->local;
1316 	struct cfg80211_bss *cbss;
1317 	struct ieee80211_channel *chan = NULL;
1318 	const u8 *bssid = NULL;
1319 	enum nl80211_bss_scan_width scan_width;
1320 	int active_ibss;
1321 	u16 capability;
1322 
1323 	sdata_assert_lock(sdata);
1324 
1325 	active_ibss = ieee80211_sta_active_ibss(sdata);
1326 	ibss_dbg(sdata, "sta_find_ibss (active_ibss=%d)\n", active_ibss);
1327 
1328 	if (active_ibss)
1329 		return;
1330 
1331 	capability = WLAN_CAPABILITY_IBSS;
1332 	if (ifibss->privacy)
1333 		capability |= WLAN_CAPABILITY_PRIVACY;
1334 	if (ifibss->fixed_bssid)
1335 		bssid = ifibss->bssid;
1336 	if (ifibss->fixed_channel)
1337 		chan = ifibss->chandef.chan;
1338 	if (!is_zero_ether_addr(ifibss->bssid))
1339 		bssid = ifibss->bssid;
1340 	cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
1341 				ifibss->ssid, ifibss->ssid_len,
1342 				WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
1343 				capability);
1344 
1345 	if (cbss) {
1346 		struct ieee80211_bss *bss;
1347 
1348 		bss = (void *)cbss->priv;
1349 		ibss_dbg(sdata,
1350 			 "sta_find_ibss: selected %pM current %pM\n",
1351 			 cbss->bssid, ifibss->bssid);
1352 		sdata_info(sdata,
1353 			   "Selected IBSS BSSID %pM based on configured SSID\n",
1354 			   cbss->bssid);
1355 
1356 		ieee80211_sta_join_ibss(sdata, bss);
1357 		ieee80211_rx_bss_put(local, bss);
1358 		return;
1359 	}
1360 
1361 	/* if a fixed bssid and a fixed freq have been provided create the IBSS
1362 	 * directly and do not waste time scanning
1363 	 */
1364 	if (ifibss->fixed_bssid && ifibss->fixed_channel) {
1365 		sdata_info(sdata, "Created IBSS using preconfigured BSSID %pM\n",
1366 			   bssid);
1367 		ieee80211_sta_create_ibss(sdata);
1368 		return;
1369 	}
1370 
1371 
1372 	ibss_dbg(sdata, "sta_find_ibss: did not try to join ibss\n");
1373 
1374 	/* Selected IBSS not found in current scan results - try to scan */
1375 	if (time_after(jiffies, ifibss->last_scan_completed +
1376 					IEEE80211_SCAN_INTERVAL)) {
1377 		sdata_info(sdata, "Trigger new scan to find an IBSS to join\n");
1378 
1379 		scan_width = cfg80211_chandef_to_scan_width(&ifibss->chandef);
1380 		ieee80211_request_ibss_scan(sdata, ifibss->ssid,
1381 					    ifibss->ssid_len, chan,
1382 					    scan_width);
1383 	} else {
1384 		int interval = IEEE80211_SCAN_INTERVAL;
1385 
1386 		if (time_after(jiffies, ifibss->ibss_join_req +
1387 			       IEEE80211_IBSS_JOIN_TIMEOUT))
1388 			ieee80211_sta_create_ibss(sdata);
1389 
1390 		mod_timer(&ifibss->timer,
1391 			  round_jiffies(jiffies + interval));
1392 	}
1393 }
1394 
1395 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
1396 					struct sk_buff *req)
1397 {
1398 	struct ieee80211_mgmt *mgmt = (void *)req->data;
1399 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1400 	struct ieee80211_local *local = sdata->local;
1401 	int tx_last_beacon, len = req->len;
1402 	struct sk_buff *skb;
1403 	struct beacon_data *presp;
1404 	u8 *pos, *end;
1405 
1406 	sdata_assert_lock(sdata);
1407 
1408 	presp = rcu_dereference_protected(ifibss->presp,
1409 					  lockdep_is_held(&sdata->wdev.mtx));
1410 
1411 	if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
1412 	    len < 24 + 2 || !presp)
1413 		return;
1414 
1415 	tx_last_beacon = drv_tx_last_beacon(local);
1416 
1417 	ibss_dbg(sdata,
1418 		 "RX ProbeReq SA=%pM DA=%pM BSSID=%pM (tx_last_beacon=%d)\n",
1419 		 mgmt->sa, mgmt->da, mgmt->bssid, tx_last_beacon);
1420 
1421 	if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da))
1422 		return;
1423 
1424 	if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) &&
1425 	    !is_broadcast_ether_addr(mgmt->bssid))
1426 		return;
1427 
1428 	end = ((u8 *) mgmt) + len;
1429 	pos = mgmt->u.probe_req.variable;
1430 	if (pos[0] != WLAN_EID_SSID ||
1431 	    pos + 2 + pos[1] > end) {
1432 		ibss_dbg(sdata, "Invalid SSID IE in ProbeReq from %pM\n",
1433 			 mgmt->sa);
1434 		return;
1435 	}
1436 	if (pos[1] != 0 &&
1437 	    (pos[1] != ifibss->ssid_len ||
1438 	     memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
1439 		/* Ignore ProbeReq for foreign SSID */
1440 		return;
1441 	}
1442 
1443 	/* Reply with ProbeResp */
1444 	skb = dev_alloc_skb(local->tx_headroom + presp->head_len);
1445 	if (!skb)
1446 		return;
1447 
1448 	skb_reserve(skb, local->tx_headroom);
1449 	memcpy(skb_put(skb, presp->head_len), presp->head, presp->head_len);
1450 
1451 	memcpy(((struct ieee80211_mgmt *) skb->data)->da, mgmt->sa, ETH_ALEN);
1452 	ibss_dbg(sdata, "Sending ProbeResp to %pM\n", mgmt->sa);
1453 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
1454 
1455 	/* avoid excessive retries for probe request to wildcard SSIDs */
1456 	if (pos[1] == 0)
1457 		IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_NO_ACK;
1458 
1459 	ieee80211_tx_skb(sdata, skb);
1460 }
1461 
1462 static
1463 void ieee80211_rx_mgmt_probe_beacon(struct ieee80211_sub_if_data *sdata,
1464 				    struct ieee80211_mgmt *mgmt, size_t len,
1465 				    struct ieee80211_rx_status *rx_status)
1466 {
1467 	size_t baselen;
1468 	struct ieee802_11_elems elems;
1469 
1470 	BUILD_BUG_ON(offsetof(typeof(mgmt->u.probe_resp), variable) !=
1471 		     offsetof(typeof(mgmt->u.beacon), variable));
1472 
1473 	/*
1474 	 * either beacon or probe_resp but the variable field is at the
1475 	 * same offset
1476 	 */
1477 	baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
1478 	if (baselen > len)
1479 		return;
1480 
1481 	ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
1482 			       false, &elems);
1483 
1484 	ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems);
1485 }
1486 
1487 void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
1488 				   struct sk_buff *skb)
1489 {
1490 	struct ieee80211_rx_status *rx_status;
1491 	struct ieee80211_mgmt *mgmt;
1492 	u16 fc;
1493 	struct ieee802_11_elems elems;
1494 	int ies_len;
1495 
1496 	rx_status = IEEE80211_SKB_RXCB(skb);
1497 	mgmt = (struct ieee80211_mgmt *) skb->data;
1498 	fc = le16_to_cpu(mgmt->frame_control);
1499 
1500 	sdata_lock(sdata);
1501 
1502 	if (!sdata->u.ibss.ssid_len)
1503 		goto mgmt_out; /* not ready to merge yet */
1504 
1505 	switch (fc & IEEE80211_FCTL_STYPE) {
1506 	case IEEE80211_STYPE_PROBE_REQ:
1507 		ieee80211_rx_mgmt_probe_req(sdata, skb);
1508 		break;
1509 	case IEEE80211_STYPE_PROBE_RESP:
1510 	case IEEE80211_STYPE_BEACON:
1511 		ieee80211_rx_mgmt_probe_beacon(sdata, mgmt, skb->len,
1512 					       rx_status);
1513 		break;
1514 	case IEEE80211_STYPE_AUTH:
1515 		ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
1516 		break;
1517 	case IEEE80211_STYPE_DEAUTH:
1518 		ieee80211_rx_mgmt_deauth_ibss(sdata, mgmt, skb->len);
1519 		break;
1520 	case IEEE80211_STYPE_ACTION:
1521 		switch (mgmt->u.action.category) {
1522 		case WLAN_CATEGORY_SPECTRUM_MGMT:
1523 			ies_len = skb->len -
1524 				  offsetof(struct ieee80211_mgmt,
1525 					   u.action.u.chan_switch.variable);
1526 
1527 			if (ies_len < 0)
1528 				break;
1529 
1530 			ieee802_11_parse_elems(
1531 				mgmt->u.action.u.chan_switch.variable,
1532 				ies_len, true, &elems);
1533 
1534 			if (elems.parse_error)
1535 				break;
1536 
1537 			ieee80211_rx_mgmt_spectrum_mgmt(sdata, mgmt, skb->len,
1538 							rx_status, &elems);
1539 			break;
1540 		}
1541 	}
1542 
1543  mgmt_out:
1544 	sdata_unlock(sdata);
1545 }
1546 
1547 void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
1548 {
1549 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1550 	struct sta_info *sta;
1551 
1552 	sdata_lock(sdata);
1553 
1554 	/*
1555 	 * Work could be scheduled after scan or similar
1556 	 * when we aren't even joined (or trying) with a
1557 	 * network.
1558 	 */
1559 	if (!ifibss->ssid_len)
1560 		goto out;
1561 
1562 	spin_lock_bh(&ifibss->incomplete_lock);
1563 	while (!list_empty(&ifibss->incomplete_stations)) {
1564 		sta = list_first_entry(&ifibss->incomplete_stations,
1565 				       struct sta_info, list);
1566 		list_del(&sta->list);
1567 		spin_unlock_bh(&ifibss->incomplete_lock);
1568 
1569 		ieee80211_ibss_finish_sta(sta);
1570 		rcu_read_unlock();
1571 		spin_lock_bh(&ifibss->incomplete_lock);
1572 	}
1573 	spin_unlock_bh(&ifibss->incomplete_lock);
1574 
1575 	switch (ifibss->state) {
1576 	case IEEE80211_IBSS_MLME_SEARCH:
1577 		ieee80211_sta_find_ibss(sdata);
1578 		break;
1579 	case IEEE80211_IBSS_MLME_JOINED:
1580 		ieee80211_sta_merge_ibss(sdata);
1581 		break;
1582 	default:
1583 		WARN_ON(1);
1584 		break;
1585 	}
1586 
1587  out:
1588 	sdata_unlock(sdata);
1589 }
1590 
1591 static void ieee80211_ibss_timer(unsigned long data)
1592 {
1593 	struct ieee80211_sub_if_data *sdata =
1594 		(struct ieee80211_sub_if_data *) data;
1595 
1596 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
1597 }
1598 
1599 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
1600 {
1601 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1602 
1603 	setup_timer(&ifibss->timer, ieee80211_ibss_timer,
1604 		    (unsigned long) sdata);
1605 	INIT_LIST_HEAD(&ifibss->incomplete_stations);
1606 	spin_lock_init(&ifibss->incomplete_lock);
1607 	INIT_WORK(&ifibss->csa_connection_drop_work,
1608 		  ieee80211_csa_connection_drop_work);
1609 }
1610 
1611 /* scan finished notification */
1612 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
1613 {
1614 	struct ieee80211_sub_if_data *sdata;
1615 
1616 	mutex_lock(&local->iflist_mtx);
1617 	list_for_each_entry(sdata, &local->interfaces, list) {
1618 		if (!ieee80211_sdata_running(sdata))
1619 			continue;
1620 		if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
1621 			continue;
1622 		sdata->u.ibss.last_scan_completed = jiffies;
1623 		ieee80211_queue_work(&local->hw, &sdata->work);
1624 	}
1625 	mutex_unlock(&local->iflist_mtx);
1626 }
1627 
1628 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
1629 			struct cfg80211_ibss_params *params)
1630 {
1631 	u32 changed = 0;
1632 	u32 rate_flags;
1633 	struct ieee80211_supported_band *sband;
1634 	enum ieee80211_chanctx_mode chanmode;
1635 	struct ieee80211_local *local = sdata->local;
1636 	int radar_detect_width = 0;
1637 	int i;
1638 	int ret;
1639 
1640 	ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
1641 					    &params->chandef,
1642 					    sdata->wdev.iftype);
1643 	if (ret < 0)
1644 		return ret;
1645 
1646 	if (ret > 0) {
1647 		if (!params->userspace_handles_dfs)
1648 			return -EINVAL;
1649 		radar_detect_width = BIT(params->chandef.width);
1650 	}
1651 
1652 	chanmode = (params->channel_fixed && !ret) ?
1653 		IEEE80211_CHANCTX_SHARED : IEEE80211_CHANCTX_EXCLUSIVE;
1654 
1655 	mutex_lock(&local->chanctx_mtx);
1656 	ret = ieee80211_check_combinations(sdata, &params->chandef, chanmode,
1657 					   radar_detect_width);
1658 	mutex_unlock(&local->chanctx_mtx);
1659 	if (ret < 0)
1660 		return ret;
1661 
1662 	if (params->bssid) {
1663 		memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
1664 		sdata->u.ibss.fixed_bssid = true;
1665 	} else
1666 		sdata->u.ibss.fixed_bssid = false;
1667 
1668 	sdata->u.ibss.privacy = params->privacy;
1669 	sdata->u.ibss.control_port = params->control_port;
1670 	sdata->u.ibss.userspace_handles_dfs = params->userspace_handles_dfs;
1671 	sdata->u.ibss.basic_rates = params->basic_rates;
1672 	sdata->u.ibss.last_scan_completed = jiffies;
1673 
1674 	/* fix basic_rates if channel does not support these rates */
1675 	rate_flags = ieee80211_chandef_rate_flags(&params->chandef);
1676 	sband = local->hw.wiphy->bands[params->chandef.chan->band];
1677 	for (i = 0; i < sband->n_bitrates; i++) {
1678 		if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
1679 			sdata->u.ibss.basic_rates &= ~BIT(i);
1680 	}
1681 	memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate,
1682 	       sizeof(params->mcast_rate));
1683 
1684 	sdata->vif.bss_conf.beacon_int = params->beacon_interval;
1685 
1686 	sdata->u.ibss.chandef = params->chandef;
1687 	sdata->u.ibss.fixed_channel = params->channel_fixed;
1688 
1689 	if (params->ie) {
1690 		sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
1691 					   GFP_KERNEL);
1692 		if (sdata->u.ibss.ie)
1693 			sdata->u.ibss.ie_len = params->ie_len;
1694 	}
1695 
1696 	sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
1697 	sdata->u.ibss.ibss_join_req = jiffies;
1698 
1699 	memcpy(sdata->u.ibss.ssid, params->ssid, params->ssid_len);
1700 	sdata->u.ibss.ssid_len = params->ssid_len;
1701 
1702 	memcpy(&sdata->u.ibss.ht_capa, &params->ht_capa,
1703 	       sizeof(sdata->u.ibss.ht_capa));
1704 	memcpy(&sdata->u.ibss.ht_capa_mask, &params->ht_capa_mask,
1705 	       sizeof(sdata->u.ibss.ht_capa_mask));
1706 
1707 	/*
1708 	 * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is
1709 	 * reserved, but an HT STA shall protect HT transmissions as though
1710 	 * the HT Protection field were set to non-HT mixed mode.
1711 	 *
1712 	 * In an IBSS, the RIFS Mode field of the HT Operation element is
1713 	 * also reserved, but an HT STA shall operate as though this field
1714 	 * were set to 1.
1715 	 */
1716 
1717 	sdata->vif.bss_conf.ht_operation_mode |=
1718 		  IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED
1719 		| IEEE80211_HT_PARAM_RIFS_MODE;
1720 
1721 	changed |= BSS_CHANGED_HT;
1722 	ieee80211_bss_info_change_notify(sdata, changed);
1723 
1724 	sdata->smps_mode = IEEE80211_SMPS_OFF;
1725 	sdata->needed_rx_chains = local->rx_chains;
1726 
1727 	ieee80211_queue_work(&local->hw, &sdata->work);
1728 
1729 	return 0;
1730 }
1731 
1732 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
1733 {
1734 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1735 
1736 	ieee80211_ibss_disconnect(sdata);
1737 	ifibss->ssid_len = 0;
1738 	memset(ifibss->bssid, 0, ETH_ALEN);
1739 
1740 	/* remove beacon */
1741 	kfree(sdata->u.ibss.ie);
1742 
1743 	/* on the next join, re-program HT parameters */
1744 	memset(&ifibss->ht_capa, 0, sizeof(ifibss->ht_capa));
1745 	memset(&ifibss->ht_capa_mask, 0, sizeof(ifibss->ht_capa_mask));
1746 
1747 	synchronize_rcu();
1748 
1749 	skb_queue_purge(&sdata->skb_queue);
1750 
1751 	del_timer_sync(&sdata->u.ibss.timer);
1752 
1753 	return 0;
1754 }
1755