xref: /linux/net/mac80211/ibss.c (revision be239684b18e1cdcafcf8c7face4a2f562c745ad)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * IBSS mode implementation
4  * Copyright 2003-2008, Jouni Malinen <j@w1.fi>
5  * Copyright 2004, Instant802 Networks, Inc.
6  * Copyright 2005, Devicescape Software, Inc.
7  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
8  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
9  * Copyright 2009, Johannes Berg <johannes@sipsolutions.net>
10  * Copyright 2013-2014  Intel Mobile Communications GmbH
11  * Copyright(c) 2016 Intel Deutschland GmbH
12  * Copyright(c) 2018-2023 Intel Corporation
13  */
14 
15 #include <linux/delay.h>
16 #include <linux/slab.h>
17 #include <linux/if_ether.h>
18 #include <linux/skbuff.h>
19 #include <linux/if_arp.h>
20 #include <linux/etherdevice.h>
21 #include <linux/rtnetlink.h>
22 #include <net/mac80211.h>
23 
24 #include "ieee80211_i.h"
25 #include "driver-ops.h"
26 #include "rate.h"
27 
28 #define IEEE80211_SCAN_INTERVAL (2 * HZ)
29 #define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)
30 
31 #define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
32 #define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)
33 #define IEEE80211_IBSS_RSN_INACTIVITY_LIMIT (10 * HZ)
34 
35 #define IEEE80211_IBSS_MAX_STA_ENTRIES 128
36 
37 static struct beacon_data *
38 ieee80211_ibss_build_presp(struct ieee80211_sub_if_data *sdata,
39 			   const int beacon_int, const u32 basic_rates,
40 			   const u16 capability, u64 tsf,
41 			   struct cfg80211_chan_def *chandef,
42 			   bool *have_higher_than_11mbit,
43 			   struct cfg80211_csa_settings *csa_settings)
44 {
45 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
46 	struct ieee80211_local *local = sdata->local;
47 	int rates_n = 0, i, ri;
48 	struct ieee80211_mgmt *mgmt;
49 	u8 *pos;
50 	struct ieee80211_supported_band *sband;
51 	u32 rate_flags, rates = 0, rates_added = 0;
52 	struct beacon_data *presp;
53 	int frame_len;
54 
55 	/* Build IBSS probe response */
56 	frame_len = sizeof(struct ieee80211_hdr_3addr) +
57 		    12 /* struct ieee80211_mgmt.u.beacon */ +
58 		    2 + IEEE80211_MAX_SSID_LEN /* max SSID */ +
59 		    2 + 8 /* max Supported Rates */ +
60 		    3 /* max DS params */ +
61 		    4 /* IBSS params */ +
62 		    5 /* Channel Switch Announcement */ +
63 		    2 + (IEEE80211_MAX_SUPP_RATES - 8) +
64 		    2 + sizeof(struct ieee80211_ht_cap) +
65 		    2 + sizeof(struct ieee80211_ht_operation) +
66 		    2 + sizeof(struct ieee80211_vht_cap) +
67 		    2 + sizeof(struct ieee80211_vht_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 	rates_n = 0;
95 	if (have_higher_than_11mbit)
96 		*have_higher_than_11mbit = false;
97 
98 	for (i = 0; i < sband->n_bitrates; i++) {
99 		if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
100 			continue;
101 		if (sband->bitrates[i].bitrate > 110 &&
102 		    have_higher_than_11mbit)
103 			*have_higher_than_11mbit = true;
104 
105 		rates |= BIT(i);
106 		rates_n++;
107 	}
108 
109 	*pos++ = WLAN_EID_SUPP_RATES;
110 	*pos++ = min_t(int, 8, rates_n);
111 	for (ri = 0; ri < sband->n_bitrates; ri++) {
112 		int rate = DIV_ROUND_UP(sband->bitrates[ri].bitrate, 5);
113 		u8 basic = 0;
114 		if (!(rates & BIT(ri)))
115 			continue;
116 
117 		if (basic_rates & BIT(ri))
118 			basic = 0x80;
119 		*pos++ = basic | (u8) rate;
120 		if (++rates_added == 8) {
121 			ri++; /* continue at next rate for EXT_SUPP_RATES */
122 			break;
123 		}
124 	}
125 
126 	if (sband->band == NL80211_BAND_2GHZ) {
127 		*pos++ = WLAN_EID_DS_PARAMS;
128 		*pos++ = 1;
129 		*pos++ = ieee80211_frequency_to_channel(
130 				chandef->chan->center_freq);
131 	}
132 
133 	*pos++ = WLAN_EID_IBSS_PARAMS;
134 	*pos++ = 2;
135 	/* FIX: set ATIM window based on scan results */
136 	*pos++ = 0;
137 	*pos++ = 0;
138 
139 	if (csa_settings) {
140 		*pos++ = WLAN_EID_CHANNEL_SWITCH;
141 		*pos++ = 3;
142 		*pos++ = csa_settings->block_tx ? 1 : 0;
143 		*pos++ = ieee80211_frequency_to_channel(
144 				csa_settings->chandef.chan->center_freq);
145 		presp->cntdwn_counter_offsets[0] = (pos - presp->head);
146 		*pos++ = csa_settings->count;
147 		presp->cntdwn_current_counter = csa_settings->count;
148 	}
149 
150 	/* put the remaining rates in WLAN_EID_EXT_SUPP_RATES */
151 	if (rates_n > 8) {
152 		*pos++ = WLAN_EID_EXT_SUPP_RATES;
153 		*pos++ = rates_n - 8;
154 		for (; ri < sband->n_bitrates; ri++) {
155 			int rate = DIV_ROUND_UP(sband->bitrates[ri].bitrate, 5);
156 			u8 basic = 0;
157 			if (!(rates & BIT(ri)))
158 				continue;
159 
160 			if (basic_rates & BIT(ri))
161 				basic = 0x80;
162 			*pos++ = basic | (u8) rate;
163 		}
164 	}
165 
166 	if (ifibss->ie_len) {
167 		memcpy(pos, ifibss->ie, ifibss->ie_len);
168 		pos += ifibss->ie_len;
169 	}
170 
171 	/* add HT capability and information IEs */
172 	if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT &&
173 	    chandef->width != NL80211_CHAN_WIDTH_5 &&
174 	    chandef->width != NL80211_CHAN_WIDTH_10 &&
175 	    sband->ht_cap.ht_supported) {
176 		struct ieee80211_sta_ht_cap ht_cap;
177 
178 		memcpy(&ht_cap, &sband->ht_cap, sizeof(ht_cap));
179 		ieee80211_apply_htcap_overrides(sdata, &ht_cap);
180 
181 		pos = ieee80211_ie_build_ht_cap(pos, &ht_cap, ht_cap.cap);
182 		/*
183 		 * Note: According to 802.11n-2009 9.13.3.1, HT Protection
184 		 * field and RIFS Mode are reserved in IBSS mode, therefore
185 		 * keep them at 0
186 		 */
187 		pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap,
188 						 chandef, 0, false);
189 
190 		/* add VHT capability and information IEs */
191 		if (chandef->width != NL80211_CHAN_WIDTH_20 &&
192 		    chandef->width != NL80211_CHAN_WIDTH_40 &&
193 		    sband->vht_cap.vht_supported) {
194 			pos = ieee80211_ie_build_vht_cap(pos, &sband->vht_cap,
195 							 sband->vht_cap.cap);
196 			pos = ieee80211_ie_build_vht_oper(pos, &sband->vht_cap,
197 							  chandef);
198 		}
199 	}
200 
201 	if (local->hw.queues >= IEEE80211_NUM_ACS)
202 		pos = ieee80211_add_wmm_info_ie(pos, 0); /* U-APSD not in use */
203 
204 	presp->head_len = pos - presp->head;
205 	if (WARN_ON(presp->head_len > frame_len))
206 		goto error;
207 
208 	return presp;
209 error:
210 	kfree(presp);
211 	return NULL;
212 }
213 
214 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
215 				      const u8 *bssid, const int beacon_int,
216 				      struct cfg80211_chan_def *req_chandef,
217 				      const u32 basic_rates,
218 				      const u16 capability, u64 tsf,
219 				      bool creator)
220 {
221 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
222 	struct ieee80211_local *local = sdata->local;
223 	struct ieee80211_mgmt *mgmt;
224 	struct cfg80211_bss *bss;
225 	u64 bss_change;
226 	struct cfg80211_chan_def chandef;
227 	struct ieee80211_channel *chan;
228 	struct beacon_data *presp;
229 	struct cfg80211_inform_bss bss_meta = {};
230 	bool have_higher_than_11mbit;
231 	bool radar_required;
232 	int err;
233 
234 	lockdep_assert_wiphy(local->hw.wiphy);
235 
236 	/* Reset own TSF to allow time synchronization work. */
237 	drv_reset_tsf(local, sdata);
238 
239 	if (!ether_addr_equal(ifibss->bssid, bssid))
240 		sta_info_flush(sdata);
241 
242 	/* if merging, indicate to driver that we leave the old IBSS */
243 	if (sdata->vif.cfg.ibss_joined) {
244 		sdata->vif.cfg.ibss_joined = false;
245 		sdata->vif.cfg.ibss_creator = false;
246 		sdata->vif.bss_conf.enable_beacon = false;
247 		netif_carrier_off(sdata->dev);
248 		ieee80211_bss_info_change_notify(sdata,
249 						 BSS_CHANGED_IBSS |
250 						 BSS_CHANGED_BEACON_ENABLED);
251 		drv_leave_ibss(local, sdata);
252 	}
253 
254 	presp = sdata_dereference(ifibss->presp, sdata);
255 	RCU_INIT_POINTER(ifibss->presp, NULL);
256 	if (presp)
257 		kfree_rcu(presp, rcu_head);
258 
259 	/* make a copy of the chandef, it could be modified below. */
260 	chandef = *req_chandef;
261 	chan = chandef.chan;
262 	if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef,
263 				     NL80211_IFTYPE_ADHOC)) {
264 		if (chandef.width == NL80211_CHAN_WIDTH_5 ||
265 		    chandef.width == NL80211_CHAN_WIDTH_10 ||
266 		    chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
267 		    chandef.width == NL80211_CHAN_WIDTH_20) {
268 			sdata_info(sdata,
269 				   "Failed to join IBSS, beacons forbidden\n");
270 			return;
271 		}
272 		chandef.width = NL80211_CHAN_WIDTH_20;
273 		chandef.center_freq1 = chan->center_freq;
274 		/* check again for downgraded chandef */
275 		if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef,
276 					     NL80211_IFTYPE_ADHOC)) {
277 			sdata_info(sdata,
278 				   "Failed to join IBSS, beacons forbidden\n");
279 			return;
280 		}
281 	}
282 
283 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
284 					    &chandef, NL80211_IFTYPE_ADHOC);
285 	if (err < 0) {
286 		sdata_info(sdata,
287 			   "Failed to join IBSS, invalid chandef\n");
288 		return;
289 	}
290 	if (err > 0 && !ifibss->userspace_handles_dfs) {
291 		sdata_info(sdata,
292 			   "Failed to join IBSS, DFS channel without control program\n");
293 		return;
294 	}
295 
296 	radar_required = err;
297 
298 	if (ieee80211_link_use_channel(&sdata->deflink, &chandef,
299 				       ifibss->fixed_channel ?
300 					IEEE80211_CHANCTX_SHARED :
301 					IEEE80211_CHANCTX_EXCLUSIVE)) {
302 		sdata_info(sdata, "Failed to join IBSS, no channel context\n");
303 		return;
304 	}
305 	sdata->deflink.radar_required = radar_required;
306 
307 	memcpy(ifibss->bssid, bssid, ETH_ALEN);
308 
309 	presp = ieee80211_ibss_build_presp(sdata, beacon_int, basic_rates,
310 					   capability, tsf, &chandef,
311 					   &have_higher_than_11mbit, NULL);
312 	if (!presp)
313 		return;
314 
315 	rcu_assign_pointer(ifibss->presp, presp);
316 	mgmt = (void *)presp->head;
317 
318 	sdata->vif.bss_conf.enable_beacon = true;
319 	sdata->vif.bss_conf.beacon_int = beacon_int;
320 	sdata->vif.bss_conf.basic_rates = basic_rates;
321 	sdata->vif.cfg.ssid_len = ifibss->ssid_len;
322 	memcpy(sdata->vif.cfg.ssid, ifibss->ssid, ifibss->ssid_len);
323 	bss_change = BSS_CHANGED_BEACON_INT;
324 	bss_change |= ieee80211_reset_erp_info(sdata);
325 	bss_change |= BSS_CHANGED_BSSID;
326 	bss_change |= BSS_CHANGED_BEACON;
327 	bss_change |= BSS_CHANGED_BEACON_ENABLED;
328 	bss_change |= BSS_CHANGED_BASIC_RATES;
329 	bss_change |= BSS_CHANGED_HT;
330 	bss_change |= BSS_CHANGED_IBSS;
331 	bss_change |= BSS_CHANGED_SSID;
332 
333 	/*
334 	 * In 5 GHz/802.11a, we can always use short slot time.
335 	 * (IEEE 802.11-2012 18.3.8.7)
336 	 *
337 	 * In 2.4GHz, we must always use long slots in IBSS for compatibility
338 	 * reasons.
339 	 * (IEEE 802.11-2012 19.4.5)
340 	 *
341 	 * HT follows these specifications (IEEE 802.11-2012 20.3.18)
342 	 */
343 	sdata->vif.bss_conf.use_short_slot = chan->band == NL80211_BAND_5GHZ;
344 	bss_change |= BSS_CHANGED_ERP_SLOT;
345 
346 	/* cf. IEEE 802.11 9.2.12 */
347 	sdata->deflink.operating_11g_mode =
348 		chan->band == NL80211_BAND_2GHZ && have_higher_than_11mbit;
349 
350 	ieee80211_set_wmm_default(&sdata->deflink, true, false);
351 
352 	sdata->vif.cfg.ibss_joined = true;
353 	sdata->vif.cfg.ibss_creator = creator;
354 
355 	err = drv_join_ibss(local, sdata);
356 	if (err) {
357 		sdata->vif.cfg.ibss_joined = false;
358 		sdata->vif.cfg.ibss_creator = false;
359 		sdata->vif.bss_conf.enable_beacon = false;
360 		sdata->vif.cfg.ssid_len = 0;
361 		RCU_INIT_POINTER(ifibss->presp, NULL);
362 		kfree_rcu(presp, rcu_head);
363 		ieee80211_link_release_channel(&sdata->deflink);
364 		sdata_info(sdata, "Failed to join IBSS, driver failure: %d\n",
365 			   err);
366 		return;
367 	}
368 
369 	ieee80211_bss_info_change_notify(sdata, bss_change);
370 
371 	ifibss->state = IEEE80211_IBSS_MLME_JOINED;
372 	mod_timer(&ifibss->timer,
373 		  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
374 
375 	bss_meta.chan = chan;
376 	bss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta, mgmt,
377 					     presp->head_len, GFP_KERNEL);
378 
379 	cfg80211_put_bss(local->hw.wiphy, bss);
380 	netif_carrier_on(sdata->dev);
381 	cfg80211_ibss_joined(sdata->dev, ifibss->bssid, chan, GFP_KERNEL);
382 }
383 
384 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
385 				    struct ieee80211_bss *bss)
386 {
387 	struct cfg80211_bss *cbss =
388 		container_of((void *)bss, struct cfg80211_bss, priv);
389 	struct ieee80211_supported_band *sband;
390 	struct cfg80211_chan_def chandef;
391 	u32 basic_rates;
392 	int i, j;
393 	u16 beacon_int = cbss->beacon_interval;
394 	const struct cfg80211_bss_ies *ies;
395 	enum nl80211_channel_type chan_type;
396 	u64 tsf;
397 	u32 rate_flags;
398 
399 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
400 
401 	if (beacon_int < 10)
402 		beacon_int = 10;
403 
404 	switch (sdata->u.ibss.chandef.width) {
405 	case NL80211_CHAN_WIDTH_20_NOHT:
406 	case NL80211_CHAN_WIDTH_20:
407 	case NL80211_CHAN_WIDTH_40:
408 		chan_type = cfg80211_get_chandef_type(&sdata->u.ibss.chandef);
409 		cfg80211_chandef_create(&chandef, cbss->channel, chan_type);
410 		break;
411 	case NL80211_CHAN_WIDTH_5:
412 	case NL80211_CHAN_WIDTH_10:
413 		cfg80211_chandef_create(&chandef, cbss->channel,
414 					NL80211_CHAN_NO_HT);
415 		chandef.width = sdata->u.ibss.chandef.width;
416 		break;
417 	case NL80211_CHAN_WIDTH_80:
418 	case NL80211_CHAN_WIDTH_80P80:
419 	case NL80211_CHAN_WIDTH_160:
420 		chandef = sdata->u.ibss.chandef;
421 		chandef.chan = cbss->channel;
422 		break;
423 	default:
424 		/* fall back to 20 MHz for unsupported modes */
425 		cfg80211_chandef_create(&chandef, cbss->channel,
426 					NL80211_CHAN_NO_HT);
427 		break;
428 	}
429 
430 	sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
431 	rate_flags = ieee80211_chandef_rate_flags(&sdata->u.ibss.chandef);
432 
433 	basic_rates = 0;
434 
435 	for (i = 0; i < bss->supp_rates_len; i++) {
436 		int rate = bss->supp_rates[i] & 0x7f;
437 		bool is_basic = !!(bss->supp_rates[i] & 0x80);
438 
439 		for (j = 0; j < sband->n_bitrates; j++) {
440 			int brate;
441 			if ((rate_flags & sband->bitrates[j].flags)
442 			    != rate_flags)
443 				continue;
444 
445 			brate = DIV_ROUND_UP(sband->bitrates[j].bitrate, 5);
446 			if (brate == rate) {
447 				if (is_basic)
448 					basic_rates |= BIT(j);
449 				break;
450 			}
451 		}
452 	}
453 
454 	rcu_read_lock();
455 	ies = rcu_dereference(cbss->ies);
456 	tsf = ies->tsf;
457 	rcu_read_unlock();
458 
459 	__ieee80211_sta_join_ibss(sdata, cbss->bssid,
460 				  beacon_int,
461 				  &chandef,
462 				  basic_rates,
463 				  cbss->capability,
464 				  tsf, false);
465 }
466 
467 int ieee80211_ibss_csa_beacon(struct ieee80211_sub_if_data *sdata,
468 			      struct cfg80211_csa_settings *csa_settings,
469 			      u64 *changed)
470 {
471 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
472 	struct beacon_data *presp, *old_presp;
473 	struct cfg80211_bss *cbss;
474 	const struct cfg80211_bss_ies *ies;
475 	u16 capability = WLAN_CAPABILITY_IBSS;
476 	u64 tsf;
477 
478 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
479 
480 	if (ifibss->privacy)
481 		capability |= WLAN_CAPABILITY_PRIVACY;
482 
483 	cbss = cfg80211_get_bss(sdata->local->hw.wiphy, ifibss->chandef.chan,
484 				ifibss->bssid, ifibss->ssid,
485 				ifibss->ssid_len, IEEE80211_BSS_TYPE_IBSS,
486 				IEEE80211_PRIVACY(ifibss->privacy));
487 
488 	if (unlikely(!cbss))
489 		return -EINVAL;
490 
491 	rcu_read_lock();
492 	ies = rcu_dereference(cbss->ies);
493 	tsf = ies->tsf;
494 	rcu_read_unlock();
495 	cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
496 
497 	old_presp = sdata_dereference(ifibss->presp, sdata);
498 
499 	presp = ieee80211_ibss_build_presp(sdata,
500 					   sdata->vif.bss_conf.beacon_int,
501 					   sdata->vif.bss_conf.basic_rates,
502 					   capability, tsf, &ifibss->chandef,
503 					   NULL, csa_settings);
504 	if (!presp)
505 		return -ENOMEM;
506 
507 	rcu_assign_pointer(ifibss->presp, presp);
508 	if (old_presp)
509 		kfree_rcu(old_presp, rcu_head);
510 
511 	*changed |= BSS_CHANGED_BEACON;
512 	return 0;
513 }
514 
515 int ieee80211_ibss_finish_csa(struct ieee80211_sub_if_data *sdata, u64 *changed)
516 {
517 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
518 	struct cfg80211_bss *cbss;
519 
520 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
521 
522 	/* When not connected/joined, sending CSA doesn't make sense. */
523 	if (ifibss->state != IEEE80211_IBSS_MLME_JOINED)
524 		return -ENOLINK;
525 
526 	/* update cfg80211 bss information with the new channel */
527 	if (!is_zero_ether_addr(ifibss->bssid)) {
528 		cbss = cfg80211_get_bss(sdata->local->hw.wiphy,
529 					ifibss->chandef.chan,
530 					ifibss->bssid, ifibss->ssid,
531 					ifibss->ssid_len,
532 					IEEE80211_BSS_TYPE_IBSS,
533 					IEEE80211_PRIVACY(ifibss->privacy));
534 		/* XXX: should not really modify cfg80211 data */
535 		if (cbss) {
536 			cbss->channel = sdata->deflink.csa_chandef.chan;
537 			cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
538 		}
539 	}
540 
541 	ifibss->chandef = sdata->deflink.csa_chandef;
542 
543 	/* generate the beacon */
544 	return ieee80211_ibss_csa_beacon(sdata, NULL, changed);
545 }
546 
547 void ieee80211_ibss_stop(struct ieee80211_sub_if_data *sdata)
548 {
549 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
550 
551 	wiphy_work_cancel(sdata->local->hw.wiphy,
552 			  &ifibss->csa_connection_drop_work);
553 }
554 
555 static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta)
556 	__acquires(RCU)
557 {
558 	struct ieee80211_sub_if_data *sdata = sta->sdata;
559 	u8 addr[ETH_ALEN];
560 
561 	memcpy(addr, sta->sta.addr, ETH_ALEN);
562 
563 	ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr);
564 
565 	sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
566 	sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
567 	/* authorize the station only if the network is not RSN protected. If
568 	 * not wait for the userspace to authorize it */
569 	if (!sta->sdata->u.ibss.control_port)
570 		sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
571 
572 	rate_control_rate_init(sta);
573 
574 	/* If it fails, maybe we raced another insertion? */
575 	if (sta_info_insert_rcu(sta))
576 		return sta_info_get(sdata, addr);
577 	return sta;
578 }
579 
580 static struct sta_info *
581 ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, const u8 *bssid,
582 		       const u8 *addr, u32 supp_rates)
583 	__acquires(RCU)
584 {
585 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
586 	struct ieee80211_local *local = sdata->local;
587 	struct sta_info *sta;
588 	struct ieee80211_chanctx_conf *chanctx_conf;
589 	struct ieee80211_supported_band *sband;
590 	int band;
591 
592 	/*
593 	 * XXX: Consider removing the least recently used entry and
594 	 * 	allow new one to be added.
595 	 */
596 	if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
597 		net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
598 				    sdata->name, addr);
599 		rcu_read_lock();
600 		return NULL;
601 	}
602 
603 	if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) {
604 		rcu_read_lock();
605 		return NULL;
606 	}
607 
608 	if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) {
609 		rcu_read_lock();
610 		return NULL;
611 	}
612 
613 	rcu_read_lock();
614 	chanctx_conf = rcu_dereference(sdata->vif.bss_conf.chanctx_conf);
615 	if (WARN_ON_ONCE(!chanctx_conf))
616 		return NULL;
617 	band = chanctx_conf->def.chan->band;
618 	rcu_read_unlock();
619 
620 	sta = sta_info_alloc(sdata, addr, GFP_KERNEL);
621 	if (!sta) {
622 		rcu_read_lock();
623 		return NULL;
624 	}
625 
626 	/* make sure mandatory rates are always added */
627 	sband = local->hw.wiphy->bands[band];
628 	sta->sta.deflink.supp_rates[band] = supp_rates |
629 			ieee80211_mandatory_rates(sband);
630 
631 	return ieee80211_ibss_finish_sta(sta);
632 }
633 
634 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
635 {
636 	struct ieee80211_local *local = sdata->local;
637 	int active = 0;
638 	struct sta_info *sta;
639 
640 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
641 
642 	rcu_read_lock();
643 
644 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
645 		unsigned long last_active = ieee80211_sta_last_active(sta);
646 
647 		if (sta->sdata == sdata &&
648 		    time_is_after_jiffies(last_active +
649 					  IEEE80211_IBSS_MERGE_INTERVAL)) {
650 			active++;
651 			break;
652 		}
653 	}
654 
655 	rcu_read_unlock();
656 
657 	return active;
658 }
659 
660 static void ieee80211_ibss_disconnect(struct ieee80211_sub_if_data *sdata)
661 {
662 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
663 	struct ieee80211_local *local = sdata->local;
664 	struct cfg80211_bss *cbss;
665 	struct beacon_data *presp;
666 	struct sta_info *sta;
667 
668 	lockdep_assert_wiphy(local->hw.wiphy);
669 
670 	if (!is_zero_ether_addr(ifibss->bssid)) {
671 		cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->chandef.chan,
672 					ifibss->bssid, ifibss->ssid,
673 					ifibss->ssid_len,
674 					IEEE80211_BSS_TYPE_IBSS,
675 					IEEE80211_PRIVACY(ifibss->privacy));
676 
677 		if (cbss) {
678 			cfg80211_unlink_bss(local->hw.wiphy, cbss);
679 			cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
680 		}
681 	}
682 
683 	ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
684 
685 	sta_info_flush(sdata);
686 
687 	spin_lock_bh(&ifibss->incomplete_lock);
688 	while (!list_empty(&ifibss->incomplete_stations)) {
689 		sta = list_first_entry(&ifibss->incomplete_stations,
690 				       struct sta_info, list);
691 		list_del(&sta->list);
692 		spin_unlock_bh(&ifibss->incomplete_lock);
693 
694 		sta_info_free(local, sta);
695 		spin_lock_bh(&ifibss->incomplete_lock);
696 	}
697 	spin_unlock_bh(&ifibss->incomplete_lock);
698 
699 	netif_carrier_off(sdata->dev);
700 
701 	sdata->vif.cfg.ibss_joined = false;
702 	sdata->vif.cfg.ibss_creator = false;
703 	sdata->vif.bss_conf.enable_beacon = false;
704 	sdata->vif.cfg.ssid_len = 0;
705 
706 	/* remove beacon */
707 	presp = sdata_dereference(ifibss->presp, sdata);
708 	RCU_INIT_POINTER(sdata->u.ibss.presp, NULL);
709 	if (presp)
710 		kfree_rcu(presp, rcu_head);
711 
712 	clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
713 	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
714 						BSS_CHANGED_IBSS);
715 	drv_leave_ibss(local, sdata);
716 	ieee80211_link_release_channel(&sdata->deflink);
717 }
718 
719 static void ieee80211_csa_connection_drop_work(struct wiphy *wiphy,
720 					       struct wiphy_work *work)
721 {
722 	struct ieee80211_sub_if_data *sdata =
723 		container_of(work, struct ieee80211_sub_if_data,
724 			     u.ibss.csa_connection_drop_work);
725 
726 	ieee80211_ibss_disconnect(sdata);
727 	synchronize_rcu();
728 	skb_queue_purge(&sdata->skb_queue);
729 
730 	/* trigger a scan to find another IBSS network to join */
731 	wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
732 }
733 
734 static void ieee80211_ibss_csa_mark_radar(struct ieee80211_sub_if_data *sdata)
735 {
736 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
737 	int err;
738 
739 	/* if the current channel is a DFS channel, mark the channel as
740 	 * unavailable.
741 	 */
742 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
743 					    &ifibss->chandef,
744 					    NL80211_IFTYPE_ADHOC);
745 	if (err > 0)
746 		cfg80211_radar_event(sdata->local->hw.wiphy, &ifibss->chandef,
747 				     GFP_ATOMIC);
748 }
749 
750 static bool
751 ieee80211_ibss_process_chanswitch(struct ieee80211_sub_if_data *sdata,
752 				  struct ieee802_11_elems *elems,
753 				  bool beacon)
754 {
755 	struct cfg80211_csa_settings params;
756 	struct ieee80211_csa_ie csa_ie;
757 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
758 	enum nl80211_channel_type ch_type;
759 	int err;
760 	ieee80211_conn_flags_t conn_flags;
761 	u32 vht_cap_info = 0;
762 
763 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
764 
765 	conn_flags = IEEE80211_CONN_DISABLE_VHT;
766 
767 	switch (ifibss->chandef.width) {
768 	case NL80211_CHAN_WIDTH_5:
769 	case NL80211_CHAN_WIDTH_10:
770 	case NL80211_CHAN_WIDTH_20_NOHT:
771 		conn_flags |= IEEE80211_CONN_DISABLE_HT;
772 		fallthrough;
773 	case NL80211_CHAN_WIDTH_20:
774 		conn_flags |= IEEE80211_CONN_DISABLE_40MHZ;
775 		break;
776 	default:
777 		break;
778 	}
779 
780 	if (elems->vht_cap_elem)
781 		vht_cap_info = le32_to_cpu(elems->vht_cap_elem->vht_cap_info);
782 
783 	memset(&params, 0, sizeof(params));
784 	err = ieee80211_parse_ch_switch_ie(sdata, elems,
785 					   ifibss->chandef.chan->band,
786 					   vht_cap_info,
787 					   conn_flags, ifibss->bssid, &csa_ie);
788 	/* can't switch to destination channel, fail */
789 	if (err < 0)
790 		goto disconnect;
791 
792 	/* did not contain a CSA */
793 	if (err)
794 		return false;
795 
796 	/* channel switch is not supported, disconnect */
797 	if (!(sdata->local->hw.wiphy->flags & WIPHY_FLAG_HAS_CHANNEL_SWITCH))
798 		goto disconnect;
799 
800 	params.count = csa_ie.count;
801 	params.chandef = csa_ie.chandef;
802 
803 	switch (ifibss->chandef.width) {
804 	case NL80211_CHAN_WIDTH_20_NOHT:
805 	case NL80211_CHAN_WIDTH_20:
806 	case NL80211_CHAN_WIDTH_40:
807 		/* keep our current HT mode (HT20/HT40+/HT40-), even if
808 		 * another mode  has been announced. The mode is not adopted
809 		 * within the beacon while doing CSA and we should therefore
810 		 * keep the mode which we announce.
811 		 */
812 		ch_type = cfg80211_get_chandef_type(&ifibss->chandef);
813 		cfg80211_chandef_create(&params.chandef, params.chandef.chan,
814 					ch_type);
815 		break;
816 	case NL80211_CHAN_WIDTH_5:
817 	case NL80211_CHAN_WIDTH_10:
818 		if (params.chandef.width != ifibss->chandef.width) {
819 			sdata_info(sdata,
820 				   "IBSS %pM received channel switch from incompatible channel width (%d MHz, width:%d, CF1/2: %d/%d MHz), disconnecting\n",
821 				   ifibss->bssid,
822 				   params.chandef.chan->center_freq,
823 				   params.chandef.width,
824 				   params.chandef.center_freq1,
825 				   params.chandef.center_freq2);
826 			goto disconnect;
827 		}
828 		break;
829 	default:
830 		/* should not happen, conn_flags should prevent VHT modes. */
831 		WARN_ON(1);
832 		goto disconnect;
833 	}
834 
835 	if (!cfg80211_reg_can_beacon(sdata->local->hw.wiphy, &params.chandef,
836 				     NL80211_IFTYPE_ADHOC)) {
837 		sdata_info(sdata,
838 			   "IBSS %pM switches to unsupported channel (%d MHz, width:%d, CF1/2: %d/%d MHz), disconnecting\n",
839 			   ifibss->bssid,
840 			   params.chandef.chan->center_freq,
841 			   params.chandef.width,
842 			   params.chandef.center_freq1,
843 			   params.chandef.center_freq2);
844 		goto disconnect;
845 	}
846 
847 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
848 					    &params.chandef,
849 					    NL80211_IFTYPE_ADHOC);
850 	if (err < 0)
851 		goto disconnect;
852 	if (err > 0 && !ifibss->userspace_handles_dfs) {
853 		/* IBSS-DFS only allowed with a control program */
854 		goto disconnect;
855 	}
856 
857 	params.radar_required = err;
858 
859 	if (cfg80211_chandef_identical(&params.chandef,
860 				       &sdata->vif.bss_conf.chandef)) {
861 		ibss_dbg(sdata,
862 			 "received csa with an identical chandef, ignoring\n");
863 		return true;
864 	}
865 
866 	/* all checks done, now perform the channel switch. */
867 	ibss_dbg(sdata,
868 		 "received channel switch announcement to go to channel %d MHz\n",
869 		 params.chandef.chan->center_freq);
870 
871 	params.block_tx = !!csa_ie.mode;
872 
873 	if (ieee80211_channel_switch(sdata->local->hw.wiphy, sdata->dev,
874 				     &params))
875 		goto disconnect;
876 
877 	ieee80211_ibss_csa_mark_radar(sdata);
878 
879 	return true;
880 disconnect:
881 	ibss_dbg(sdata, "Can't handle channel switch, disconnect\n");
882 	wiphy_work_queue(sdata->local->hw.wiphy,
883 			 &ifibss->csa_connection_drop_work);
884 
885 	ieee80211_ibss_csa_mark_radar(sdata);
886 
887 	return true;
888 }
889 
890 static void
891 ieee80211_rx_mgmt_spectrum_mgmt(struct ieee80211_sub_if_data *sdata,
892 				struct ieee80211_mgmt *mgmt, size_t len,
893 				struct ieee80211_rx_status *rx_status,
894 				struct ieee802_11_elems *elems)
895 {
896 	int required_len;
897 
898 	if (len < IEEE80211_MIN_ACTION_SIZE + 1)
899 		return;
900 
901 	/* CSA is the only action we handle for now */
902 	if (mgmt->u.action.u.measurement.action_code !=
903 	    WLAN_ACTION_SPCT_CHL_SWITCH)
904 		return;
905 
906 	required_len = IEEE80211_MIN_ACTION_SIZE +
907 		       sizeof(mgmt->u.action.u.chan_switch);
908 	if (len < required_len)
909 		return;
910 
911 	if (!sdata->vif.bss_conf.csa_active)
912 		ieee80211_ibss_process_chanswitch(sdata, elems, false);
913 }
914 
915 static void ieee80211_rx_mgmt_deauth_ibss(struct ieee80211_sub_if_data *sdata,
916 					  struct ieee80211_mgmt *mgmt,
917 					  size_t len)
918 {
919 	u16 reason = le16_to_cpu(mgmt->u.deauth.reason_code);
920 
921 	if (len < IEEE80211_DEAUTH_FRAME_LEN)
922 		return;
923 
924 	ibss_dbg(sdata, "RX DeAuth SA=%pM DA=%pM\n", mgmt->sa, mgmt->da);
925 	ibss_dbg(sdata, "\tBSSID=%pM (reason: %d)\n", mgmt->bssid, reason);
926 	sta_info_destroy_addr(sdata, mgmt->sa);
927 }
928 
929 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
930 					struct ieee80211_mgmt *mgmt,
931 					size_t len)
932 {
933 	u16 auth_alg, auth_transaction;
934 
935 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
936 
937 	if (len < 24 + 6)
938 		return;
939 
940 	auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
941 	auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
942 
943 	ibss_dbg(sdata, "RX Auth SA=%pM DA=%pM\n", mgmt->sa, mgmt->da);
944 	ibss_dbg(sdata, "\tBSSID=%pM (auth_transaction=%d)\n",
945 		 mgmt->bssid, auth_transaction);
946 
947 	if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1)
948 		return;
949 
950 	/*
951 	 * IEEE 802.11 standard does not require authentication in IBSS
952 	 * networks and most implementations do not seem to use it.
953 	 * However, try to reply to authentication attempts if someone
954 	 * has actually implemented this.
955 	 */
956 	ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, 0, NULL, 0,
957 			    mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0, 0);
958 }
959 
960 static void ieee80211_update_sta_info(struct ieee80211_sub_if_data *sdata,
961 				      struct ieee80211_mgmt *mgmt, size_t len,
962 				      struct ieee80211_rx_status *rx_status,
963 				      struct ieee802_11_elems *elems,
964 				      struct ieee80211_channel *channel)
965 {
966 	struct sta_info *sta;
967 	enum nl80211_band band = rx_status->band;
968 	struct ieee80211_local *local = sdata->local;
969 	struct ieee80211_supported_band *sband;
970 	bool rates_updated = false;
971 	u32 supp_rates = 0;
972 
973 	if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
974 		return;
975 
976 	if (!ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid))
977 		return;
978 
979 	sband = local->hw.wiphy->bands[band];
980 	if (WARN_ON(!sband))
981 		return;
982 
983 	rcu_read_lock();
984 	sta = sta_info_get(sdata, mgmt->sa);
985 
986 	if (elems->supp_rates) {
987 		supp_rates = ieee80211_sta_get_rates(sdata, elems,
988 						     band, NULL);
989 		if (sta) {
990 			u32 prev_rates;
991 
992 			prev_rates = sta->sta.deflink.supp_rates[band];
993 
994 			sta->sta.deflink.supp_rates[band] = supp_rates |
995 				ieee80211_mandatory_rates(sband);
996 			if (sta->sta.deflink.supp_rates[band] != prev_rates) {
997 				ibss_dbg(sdata,
998 					 "updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n",
999 					 sta->sta.addr, prev_rates,
1000 					 sta->sta.deflink.supp_rates[band]);
1001 				rates_updated = true;
1002 			}
1003 		} else {
1004 			rcu_read_unlock();
1005 			sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
1006 						     mgmt->sa, supp_rates);
1007 		}
1008 	}
1009 
1010 	if (sta && !sta->sta.wme &&
1011 	    (elems->wmm_info || elems->s1g_capab) &&
1012 	    local->hw.queues >= IEEE80211_NUM_ACS) {
1013 		sta->sta.wme = true;
1014 		ieee80211_check_fast_xmit(sta);
1015 	}
1016 
1017 	if (sta && elems->ht_operation && elems->ht_cap_elem &&
1018 	    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_20_NOHT &&
1019 	    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_5 &&
1020 	    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_10) {
1021 		/* we both use HT */
1022 		struct ieee80211_ht_cap htcap_ie;
1023 		struct cfg80211_chan_def chandef;
1024 		enum ieee80211_sta_rx_bandwidth bw = sta->sta.deflink.bandwidth;
1025 
1026 		cfg80211_chandef_create(&chandef, channel, NL80211_CHAN_NO_HT);
1027 		ieee80211_chandef_ht_oper(elems->ht_operation, &chandef);
1028 
1029 		memcpy(&htcap_ie, elems->ht_cap_elem, sizeof(htcap_ie));
1030 		rates_updated |= ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
1031 								   &htcap_ie,
1032 								   &sta->deflink);
1033 
1034 		if (elems->vht_operation && elems->vht_cap_elem &&
1035 		    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_20 &&
1036 		    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_40) {
1037 			/* we both use VHT */
1038 			struct ieee80211_vht_cap cap_ie;
1039 			struct ieee80211_sta_vht_cap cap = sta->sta.deflink.vht_cap;
1040 			u32 vht_cap_info =
1041 				le32_to_cpu(elems->vht_cap_elem->vht_cap_info);
1042 
1043 			ieee80211_chandef_vht_oper(&local->hw, vht_cap_info,
1044 						   elems->vht_operation,
1045 						   elems->ht_operation,
1046 						   &chandef);
1047 			memcpy(&cap_ie, elems->vht_cap_elem, sizeof(cap_ie));
1048 			ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband,
1049 							    &cap_ie, NULL,
1050 							    &sta->deflink);
1051 			if (memcmp(&cap, &sta->sta.deflink.vht_cap, sizeof(cap)))
1052 				rates_updated |= true;
1053 		}
1054 
1055 		if (bw != sta->sta.deflink.bandwidth)
1056 			rates_updated |= true;
1057 
1058 		if (!cfg80211_chandef_compatible(&sdata->u.ibss.chandef,
1059 						 &chandef))
1060 			WARN_ON_ONCE(1);
1061 	}
1062 
1063 	if (sta && rates_updated) {
1064 		u32 changed = IEEE80211_RC_SUPP_RATES_CHANGED;
1065 		u8 rx_nss = sta->sta.deflink.rx_nss;
1066 
1067 		/* Force rx_nss recalculation */
1068 		sta->sta.deflink.rx_nss = 0;
1069 		rate_control_rate_init(sta);
1070 		if (sta->sta.deflink.rx_nss != rx_nss)
1071 			changed |= IEEE80211_RC_NSS_CHANGED;
1072 
1073 		drv_sta_rc_update(local, sdata, &sta->sta, changed);
1074 	}
1075 
1076 	rcu_read_unlock();
1077 }
1078 
1079 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
1080 				  struct ieee80211_mgmt *mgmt, size_t len,
1081 				  struct ieee80211_rx_status *rx_status,
1082 				  struct ieee802_11_elems *elems)
1083 {
1084 	struct ieee80211_local *local = sdata->local;
1085 	struct cfg80211_bss *cbss;
1086 	struct ieee80211_bss *bss;
1087 	struct ieee80211_channel *channel;
1088 	u64 beacon_timestamp, rx_timestamp;
1089 	u32 supp_rates = 0;
1090 	enum nl80211_band band = rx_status->band;
1091 
1092 	channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
1093 	if (!channel)
1094 		return;
1095 
1096 	ieee80211_update_sta_info(sdata, mgmt, len, rx_status, elems, channel);
1097 
1098 	bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, channel);
1099 	if (!bss)
1100 		return;
1101 
1102 	cbss = container_of((void *)bss, struct cfg80211_bss, priv);
1103 
1104 	/* same for beacon and probe response */
1105 	beacon_timestamp = le64_to_cpu(mgmt->u.beacon.timestamp);
1106 
1107 	/* check if we need to merge IBSS */
1108 
1109 	/* not an IBSS */
1110 	if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
1111 		goto put_bss;
1112 
1113 	/* different channel */
1114 	if (sdata->u.ibss.fixed_channel &&
1115 	    sdata->u.ibss.chandef.chan != cbss->channel)
1116 		goto put_bss;
1117 
1118 	/* different SSID */
1119 	if (elems->ssid_len != sdata->u.ibss.ssid_len ||
1120 	    memcmp(elems->ssid, sdata->u.ibss.ssid,
1121 				sdata->u.ibss.ssid_len))
1122 		goto put_bss;
1123 
1124 	/* process channel switch */
1125 	if (sdata->vif.bss_conf.csa_active ||
1126 	    ieee80211_ibss_process_chanswitch(sdata, elems, true))
1127 		goto put_bss;
1128 
1129 	/* same BSSID */
1130 	if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid))
1131 		goto put_bss;
1132 
1133 	/* we use a fixed BSSID */
1134 	if (sdata->u.ibss.fixed_bssid)
1135 		goto put_bss;
1136 
1137 	if (ieee80211_have_rx_timestamp(rx_status)) {
1138 		/* time when timestamp field was received */
1139 		rx_timestamp =
1140 			ieee80211_calculate_rx_timestamp(local, rx_status,
1141 							 len + FCS_LEN, 24);
1142 	} else {
1143 		/*
1144 		 * second best option: get current TSF
1145 		 * (will return -1 if not supported)
1146 		 */
1147 		rx_timestamp = drv_get_tsf(local, sdata);
1148 	}
1149 
1150 	ibss_dbg(sdata, "RX beacon SA=%pM BSSID=%pM TSF=0x%llx\n",
1151 		 mgmt->sa, mgmt->bssid,
1152 		 (unsigned long long)rx_timestamp);
1153 	ibss_dbg(sdata, "\tBCN=0x%llx diff=%lld @%lu\n",
1154 		 (unsigned long long)beacon_timestamp,
1155 		 (unsigned long long)(rx_timestamp - beacon_timestamp),
1156 		 jiffies);
1157 
1158 	if (beacon_timestamp > rx_timestamp) {
1159 		ibss_dbg(sdata,
1160 			 "beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n",
1161 			 mgmt->bssid);
1162 		ieee80211_sta_join_ibss(sdata, bss);
1163 		supp_rates = ieee80211_sta_get_rates(sdata, elems, band, NULL);
1164 		ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
1165 				       supp_rates);
1166 		rcu_read_unlock();
1167 	}
1168 
1169  put_bss:
1170 	ieee80211_rx_bss_put(local, bss);
1171 }
1172 
1173 void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata,
1174 			      const u8 *bssid, const u8 *addr,
1175 			      u32 supp_rates)
1176 {
1177 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1178 	struct ieee80211_local *local = sdata->local;
1179 	struct sta_info *sta;
1180 	struct ieee80211_chanctx_conf *chanctx_conf;
1181 	struct ieee80211_supported_band *sband;
1182 	int band;
1183 
1184 	/*
1185 	 * XXX: Consider removing the least recently used entry and
1186 	 * 	allow new one to be added.
1187 	 */
1188 	if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
1189 		net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
1190 				    sdata->name, addr);
1191 		return;
1192 	}
1193 
1194 	if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
1195 		return;
1196 
1197 	if (!ether_addr_equal(bssid, sdata->u.ibss.bssid))
1198 		return;
1199 
1200 	rcu_read_lock();
1201 	chanctx_conf = rcu_dereference(sdata->vif.bss_conf.chanctx_conf);
1202 	if (WARN_ON_ONCE(!chanctx_conf)) {
1203 		rcu_read_unlock();
1204 		return;
1205 	}
1206 	band = chanctx_conf->def.chan->band;
1207 	rcu_read_unlock();
1208 
1209 	sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
1210 	if (!sta)
1211 		return;
1212 
1213 	/* make sure mandatory rates are always added */
1214 	sband = local->hw.wiphy->bands[band];
1215 	sta->sta.deflink.supp_rates[band] = supp_rates |
1216 			ieee80211_mandatory_rates(sband);
1217 
1218 	spin_lock(&ifibss->incomplete_lock);
1219 	list_add(&sta->list, &ifibss->incomplete_stations);
1220 	spin_unlock(&ifibss->incomplete_lock);
1221 	wiphy_work_queue(local->hw.wiphy, &sdata->work);
1222 }
1223 
1224 static void ieee80211_ibss_sta_expire(struct ieee80211_sub_if_data *sdata)
1225 {
1226 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1227 	struct ieee80211_local *local = sdata->local;
1228 	struct sta_info *sta, *tmp;
1229 	unsigned long exp_time = IEEE80211_IBSS_INACTIVITY_LIMIT;
1230 	unsigned long exp_rsn = IEEE80211_IBSS_RSN_INACTIVITY_LIMIT;
1231 
1232 	lockdep_assert_wiphy(local->hw.wiphy);
1233 
1234 	list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
1235 		unsigned long last_active = ieee80211_sta_last_active(sta);
1236 
1237 		if (sdata != sta->sdata)
1238 			continue;
1239 
1240 		if (time_is_before_jiffies(last_active + exp_time) ||
1241 		    (time_is_before_jiffies(last_active + exp_rsn) &&
1242 		     sta->sta_state != IEEE80211_STA_AUTHORIZED)) {
1243 			u8 frame_buf[IEEE80211_DEAUTH_FRAME_LEN];
1244 
1245 			sta_dbg(sta->sdata, "expiring inactive %sSTA %pM\n",
1246 				sta->sta_state != IEEE80211_STA_AUTHORIZED ?
1247 				"not authorized " : "", sta->sta.addr);
1248 
1249 			ieee80211_send_deauth_disassoc(sdata, sta->sta.addr,
1250 						       ifibss->bssid,
1251 						       IEEE80211_STYPE_DEAUTH,
1252 						       WLAN_REASON_DEAUTH_LEAVING,
1253 						       true, frame_buf);
1254 			WARN_ON(__sta_info_destroy(sta));
1255 		}
1256 	}
1257 }
1258 
1259 /*
1260  * This function is called with state == IEEE80211_IBSS_MLME_JOINED
1261  */
1262 
1263 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
1264 {
1265 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1266 
1267 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
1268 
1269 	mod_timer(&ifibss->timer,
1270 		  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
1271 
1272 	ieee80211_ibss_sta_expire(sdata);
1273 
1274 	if (time_before(jiffies, ifibss->last_scan_completed +
1275 		       IEEE80211_IBSS_MERGE_INTERVAL))
1276 		return;
1277 
1278 	if (ieee80211_sta_active_ibss(sdata))
1279 		return;
1280 
1281 	if (ifibss->fixed_channel)
1282 		return;
1283 
1284 	sdata_info(sdata,
1285 		   "No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n");
1286 
1287 	ieee80211_request_ibss_scan(sdata, ifibss->ssid, ifibss->ssid_len,
1288 				    NULL, 0);
1289 }
1290 
1291 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
1292 {
1293 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1294 	u8 bssid[ETH_ALEN];
1295 	u16 capability;
1296 	int i;
1297 
1298 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
1299 
1300 	if (ifibss->fixed_bssid) {
1301 		memcpy(bssid, ifibss->bssid, ETH_ALEN);
1302 	} else {
1303 		/* Generate random, not broadcast, locally administered BSSID. Mix in
1304 		 * own MAC address to make sure that devices that do not have proper
1305 		 * random number generator get different BSSID. */
1306 		get_random_bytes(bssid, ETH_ALEN);
1307 		for (i = 0; i < ETH_ALEN; i++)
1308 			bssid[i] ^= sdata->vif.addr[i];
1309 		bssid[0] &= ~0x01;
1310 		bssid[0] |= 0x02;
1311 	}
1312 
1313 	sdata_info(sdata, "Creating new IBSS network, BSSID %pM\n", bssid);
1314 
1315 	capability = WLAN_CAPABILITY_IBSS;
1316 
1317 	if (ifibss->privacy)
1318 		capability |= WLAN_CAPABILITY_PRIVACY;
1319 
1320 	__ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
1321 				  &ifibss->chandef, ifibss->basic_rates,
1322 				  capability, 0, true);
1323 }
1324 
1325 static unsigned int ibss_setup_channels(struct wiphy *wiphy,
1326 					struct ieee80211_channel **channels,
1327 					unsigned int channels_max,
1328 					u32 center_freq, u32 width)
1329 {
1330 	struct ieee80211_channel *chan = NULL;
1331 	unsigned int n_chan = 0;
1332 	u32 start_freq, end_freq, freq;
1333 
1334 	if (width <= 20) {
1335 		start_freq = center_freq;
1336 		end_freq = center_freq;
1337 	} else {
1338 		start_freq = center_freq - width / 2 + 10;
1339 		end_freq = center_freq + width / 2 - 10;
1340 	}
1341 
1342 	for (freq = start_freq; freq <= end_freq; freq += 20) {
1343 		chan = ieee80211_get_channel(wiphy, freq);
1344 		if (!chan)
1345 			continue;
1346 		if (n_chan >= channels_max)
1347 			return n_chan;
1348 
1349 		channels[n_chan] = chan;
1350 		n_chan++;
1351 	}
1352 
1353 	return n_chan;
1354 }
1355 
1356 static unsigned int
1357 ieee80211_ibss_setup_scan_channels(struct wiphy *wiphy,
1358 				   const struct cfg80211_chan_def *chandef,
1359 				   struct ieee80211_channel **channels,
1360 				   unsigned int channels_max)
1361 {
1362 	unsigned int n_chan = 0;
1363 	u32 width, cf1, cf2 = 0;
1364 
1365 	switch (chandef->width) {
1366 	case NL80211_CHAN_WIDTH_40:
1367 		width = 40;
1368 		break;
1369 	case NL80211_CHAN_WIDTH_80P80:
1370 		cf2 = chandef->center_freq2;
1371 		fallthrough;
1372 	case NL80211_CHAN_WIDTH_80:
1373 		width = 80;
1374 		break;
1375 	case NL80211_CHAN_WIDTH_160:
1376 		width = 160;
1377 		break;
1378 	default:
1379 		width = 20;
1380 		break;
1381 	}
1382 
1383 	cf1 = chandef->center_freq1;
1384 
1385 	n_chan = ibss_setup_channels(wiphy, channels, channels_max, cf1, width);
1386 
1387 	if (cf2)
1388 		n_chan += ibss_setup_channels(wiphy, &channels[n_chan],
1389 					      channels_max - n_chan, cf2,
1390 					      width);
1391 
1392 	return n_chan;
1393 }
1394 
1395 /*
1396  * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
1397  */
1398 
1399 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
1400 {
1401 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1402 	struct ieee80211_local *local = sdata->local;
1403 	struct cfg80211_bss *cbss;
1404 	struct ieee80211_channel *chan = NULL;
1405 	const u8 *bssid = NULL;
1406 	int active_ibss;
1407 
1408 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
1409 
1410 	active_ibss = ieee80211_sta_active_ibss(sdata);
1411 	ibss_dbg(sdata, "sta_find_ibss (active_ibss=%d)\n", active_ibss);
1412 
1413 	if (active_ibss)
1414 		return;
1415 
1416 	if (ifibss->fixed_bssid)
1417 		bssid = ifibss->bssid;
1418 	if (ifibss->fixed_channel)
1419 		chan = ifibss->chandef.chan;
1420 	if (!is_zero_ether_addr(ifibss->bssid))
1421 		bssid = ifibss->bssid;
1422 	cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
1423 				ifibss->ssid, ifibss->ssid_len,
1424 				IEEE80211_BSS_TYPE_IBSS,
1425 				IEEE80211_PRIVACY(ifibss->privacy));
1426 
1427 	if (cbss) {
1428 		struct ieee80211_bss *bss;
1429 
1430 		bss = (void *)cbss->priv;
1431 		ibss_dbg(sdata,
1432 			 "sta_find_ibss: selected %pM current %pM\n",
1433 			 cbss->bssid, ifibss->bssid);
1434 		sdata_info(sdata,
1435 			   "Selected IBSS BSSID %pM based on configured SSID\n",
1436 			   cbss->bssid);
1437 
1438 		ieee80211_sta_join_ibss(sdata, bss);
1439 		ieee80211_rx_bss_put(local, bss);
1440 		return;
1441 	}
1442 
1443 	/* if a fixed bssid and a fixed freq have been provided create the IBSS
1444 	 * directly and do not waste time scanning
1445 	 */
1446 	if (ifibss->fixed_bssid && ifibss->fixed_channel) {
1447 		sdata_info(sdata, "Created IBSS using preconfigured BSSID %pM\n",
1448 			   bssid);
1449 		ieee80211_sta_create_ibss(sdata);
1450 		return;
1451 	}
1452 
1453 
1454 	ibss_dbg(sdata, "sta_find_ibss: did not try to join ibss\n");
1455 
1456 	/* Selected IBSS not found in current scan results - try to scan */
1457 	if (time_after(jiffies, ifibss->last_scan_completed +
1458 					IEEE80211_SCAN_INTERVAL)) {
1459 		struct ieee80211_channel *channels[8];
1460 		unsigned int num;
1461 
1462 		sdata_info(sdata, "Trigger new scan to find an IBSS to join\n");
1463 
1464 		if (ifibss->fixed_channel) {
1465 			num = ieee80211_ibss_setup_scan_channels(local->hw.wiphy,
1466 								 &ifibss->chandef,
1467 								 channels,
1468 								 ARRAY_SIZE(channels));
1469 			ieee80211_request_ibss_scan(sdata, ifibss->ssid,
1470 						    ifibss->ssid_len, channels,
1471 						    num);
1472 		} else {
1473 			ieee80211_request_ibss_scan(sdata, ifibss->ssid,
1474 						    ifibss->ssid_len, NULL, 0);
1475 		}
1476 	} else {
1477 		int interval = IEEE80211_SCAN_INTERVAL;
1478 
1479 		if (time_after(jiffies, ifibss->ibss_join_req +
1480 			       IEEE80211_IBSS_JOIN_TIMEOUT))
1481 			ieee80211_sta_create_ibss(sdata);
1482 
1483 		mod_timer(&ifibss->timer,
1484 			  round_jiffies(jiffies + interval));
1485 	}
1486 }
1487 
1488 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
1489 					struct sk_buff *req)
1490 {
1491 	struct ieee80211_mgmt *mgmt = (void *)req->data;
1492 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1493 	struct ieee80211_local *local = sdata->local;
1494 	int tx_last_beacon, len = req->len;
1495 	struct sk_buff *skb;
1496 	struct beacon_data *presp;
1497 	u8 *pos, *end;
1498 
1499 	lockdep_assert_wiphy(sdata->local->hw.wiphy);
1500 
1501 	presp = sdata_dereference(ifibss->presp, sdata);
1502 
1503 	if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
1504 	    len < 24 + 2 || !presp)
1505 		return;
1506 
1507 	tx_last_beacon = drv_tx_last_beacon(local);
1508 
1509 	ibss_dbg(sdata, "RX ProbeReq SA=%pM DA=%pM\n", mgmt->sa, mgmt->da);
1510 	ibss_dbg(sdata, "\tBSSID=%pM (tx_last_beacon=%d)\n",
1511 		 mgmt->bssid, tx_last_beacon);
1512 
1513 	if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da))
1514 		return;
1515 
1516 	if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) &&
1517 	    !is_broadcast_ether_addr(mgmt->bssid))
1518 		return;
1519 
1520 	end = ((u8 *) mgmt) + len;
1521 	pos = mgmt->u.probe_req.variable;
1522 	if (pos[0] != WLAN_EID_SSID ||
1523 	    pos + 2 + pos[1] > end) {
1524 		ibss_dbg(sdata, "Invalid SSID IE in ProbeReq from %pM\n",
1525 			 mgmt->sa);
1526 		return;
1527 	}
1528 	if (pos[1] != 0 &&
1529 	    (pos[1] != ifibss->ssid_len ||
1530 	     memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
1531 		/* Ignore ProbeReq for foreign SSID */
1532 		return;
1533 	}
1534 
1535 	/* Reply with ProbeResp */
1536 	skb = dev_alloc_skb(local->tx_headroom + presp->head_len);
1537 	if (!skb)
1538 		return;
1539 
1540 	skb_reserve(skb, local->tx_headroom);
1541 	skb_put_data(skb, presp->head, presp->head_len);
1542 
1543 	memcpy(((struct ieee80211_mgmt *) skb->data)->da, mgmt->sa, ETH_ALEN);
1544 	ibss_dbg(sdata, "Sending ProbeResp to %pM\n", mgmt->sa);
1545 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
1546 
1547 	/* avoid excessive retries for probe request to wildcard SSIDs */
1548 	if (pos[1] == 0)
1549 		IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_NO_ACK;
1550 
1551 	ieee80211_tx_skb(sdata, skb);
1552 }
1553 
1554 static
1555 void ieee80211_rx_mgmt_probe_beacon(struct ieee80211_sub_if_data *sdata,
1556 				    struct ieee80211_mgmt *mgmt, size_t len,
1557 				    struct ieee80211_rx_status *rx_status)
1558 {
1559 	size_t baselen;
1560 	struct ieee802_11_elems *elems;
1561 
1562 	BUILD_BUG_ON(offsetof(typeof(mgmt->u.probe_resp), variable) !=
1563 		     offsetof(typeof(mgmt->u.beacon), variable));
1564 
1565 	/*
1566 	 * either beacon or probe_resp but the variable field is at the
1567 	 * same offset
1568 	 */
1569 	baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
1570 	if (baselen > len)
1571 		return;
1572 
1573 	elems = ieee802_11_parse_elems(mgmt->u.probe_resp.variable,
1574 				       len - baselen, false, NULL);
1575 
1576 	if (elems) {
1577 		ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, elems);
1578 		kfree(elems);
1579 	}
1580 }
1581 
1582 void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
1583 				   struct sk_buff *skb)
1584 {
1585 	struct ieee80211_rx_status *rx_status;
1586 	struct ieee80211_mgmt *mgmt;
1587 	u16 fc;
1588 	struct ieee802_11_elems *elems;
1589 	int ies_len;
1590 
1591 	rx_status = IEEE80211_SKB_RXCB(skb);
1592 	mgmt = (struct ieee80211_mgmt *) skb->data;
1593 	fc = le16_to_cpu(mgmt->frame_control);
1594 
1595 	if (!sdata->u.ibss.ssid_len)
1596 		return; /* not ready to merge yet */
1597 
1598 	switch (fc & IEEE80211_FCTL_STYPE) {
1599 	case IEEE80211_STYPE_PROBE_REQ:
1600 		ieee80211_rx_mgmt_probe_req(sdata, skb);
1601 		break;
1602 	case IEEE80211_STYPE_PROBE_RESP:
1603 	case IEEE80211_STYPE_BEACON:
1604 		ieee80211_rx_mgmt_probe_beacon(sdata, mgmt, skb->len,
1605 					       rx_status);
1606 		break;
1607 	case IEEE80211_STYPE_AUTH:
1608 		ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
1609 		break;
1610 	case IEEE80211_STYPE_DEAUTH:
1611 		ieee80211_rx_mgmt_deauth_ibss(sdata, mgmt, skb->len);
1612 		break;
1613 	case IEEE80211_STYPE_ACTION:
1614 		switch (mgmt->u.action.category) {
1615 		case WLAN_CATEGORY_SPECTRUM_MGMT:
1616 			ies_len = skb->len -
1617 				  offsetof(struct ieee80211_mgmt,
1618 					   u.action.u.chan_switch.variable);
1619 
1620 			if (ies_len < 0)
1621 				break;
1622 
1623 			elems = ieee802_11_parse_elems(
1624 				mgmt->u.action.u.chan_switch.variable,
1625 				ies_len, true, NULL);
1626 
1627 			if (elems && !elems->parse_error)
1628 				ieee80211_rx_mgmt_spectrum_mgmt(sdata, mgmt,
1629 								skb->len,
1630 								rx_status,
1631 								elems);
1632 			kfree(elems);
1633 			break;
1634 		}
1635 	}
1636 }
1637 
1638 void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
1639 {
1640 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1641 	struct sta_info *sta;
1642 
1643 	/*
1644 	 * Work could be scheduled after scan or similar
1645 	 * when we aren't even joined (or trying) with a
1646 	 * network.
1647 	 */
1648 	if (!ifibss->ssid_len)
1649 		return;
1650 
1651 	spin_lock_bh(&ifibss->incomplete_lock);
1652 	while (!list_empty(&ifibss->incomplete_stations)) {
1653 		sta = list_first_entry(&ifibss->incomplete_stations,
1654 				       struct sta_info, list);
1655 		list_del(&sta->list);
1656 		spin_unlock_bh(&ifibss->incomplete_lock);
1657 
1658 		ieee80211_ibss_finish_sta(sta);
1659 		rcu_read_unlock();
1660 		spin_lock_bh(&ifibss->incomplete_lock);
1661 	}
1662 	spin_unlock_bh(&ifibss->incomplete_lock);
1663 
1664 	switch (ifibss->state) {
1665 	case IEEE80211_IBSS_MLME_SEARCH:
1666 		ieee80211_sta_find_ibss(sdata);
1667 		break;
1668 	case IEEE80211_IBSS_MLME_JOINED:
1669 		ieee80211_sta_merge_ibss(sdata);
1670 		break;
1671 	default:
1672 		WARN_ON(1);
1673 		break;
1674 	}
1675 }
1676 
1677 static void ieee80211_ibss_timer(struct timer_list *t)
1678 {
1679 	struct ieee80211_sub_if_data *sdata =
1680 		from_timer(sdata, t, u.ibss.timer);
1681 
1682 	wiphy_work_queue(sdata->local->hw.wiphy, &sdata->work);
1683 }
1684 
1685 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
1686 {
1687 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1688 
1689 	timer_setup(&ifibss->timer, ieee80211_ibss_timer, 0);
1690 	INIT_LIST_HEAD(&ifibss->incomplete_stations);
1691 	spin_lock_init(&ifibss->incomplete_lock);
1692 	wiphy_work_init(&ifibss->csa_connection_drop_work,
1693 			ieee80211_csa_connection_drop_work);
1694 }
1695 
1696 /* scan finished notification */
1697 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
1698 {
1699 	struct ieee80211_sub_if_data *sdata;
1700 
1701 	lockdep_assert_wiphy(local->hw.wiphy);
1702 
1703 	list_for_each_entry(sdata, &local->interfaces, list) {
1704 		if (!ieee80211_sdata_running(sdata))
1705 			continue;
1706 		if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
1707 			continue;
1708 		sdata->u.ibss.last_scan_completed = jiffies;
1709 	}
1710 }
1711 
1712 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
1713 			struct cfg80211_ibss_params *params)
1714 {
1715 	u64 changed = 0;
1716 	u32 rate_flags;
1717 	struct ieee80211_supported_band *sband;
1718 	enum ieee80211_chanctx_mode chanmode;
1719 	struct ieee80211_local *local = sdata->local;
1720 	int radar_detect_width = 0;
1721 	int i;
1722 	int ret;
1723 
1724 	lockdep_assert_wiphy(local->hw.wiphy);
1725 
1726 	if (params->chandef.chan->freq_offset) {
1727 		/* this may work, but is untested */
1728 		return -EOPNOTSUPP;
1729 	}
1730 
1731 	ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
1732 					    &params->chandef,
1733 					    sdata->wdev.iftype);
1734 	if (ret < 0)
1735 		return ret;
1736 
1737 	if (ret > 0) {
1738 		if (!params->userspace_handles_dfs)
1739 			return -EINVAL;
1740 		radar_detect_width = BIT(params->chandef.width);
1741 	}
1742 
1743 	chanmode = (params->channel_fixed && !ret) ?
1744 		IEEE80211_CHANCTX_SHARED : IEEE80211_CHANCTX_EXCLUSIVE;
1745 
1746 	ret = ieee80211_check_combinations(sdata, &params->chandef, chanmode,
1747 					   radar_detect_width);
1748 	if (ret < 0)
1749 		return ret;
1750 
1751 	if (params->bssid) {
1752 		memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
1753 		sdata->u.ibss.fixed_bssid = true;
1754 	} else
1755 		sdata->u.ibss.fixed_bssid = false;
1756 
1757 	sdata->u.ibss.privacy = params->privacy;
1758 	sdata->u.ibss.control_port = params->control_port;
1759 	sdata->u.ibss.userspace_handles_dfs = params->userspace_handles_dfs;
1760 	sdata->u.ibss.basic_rates = params->basic_rates;
1761 	sdata->u.ibss.last_scan_completed = jiffies;
1762 
1763 	/* fix basic_rates if channel does not support these rates */
1764 	rate_flags = ieee80211_chandef_rate_flags(&params->chandef);
1765 	sband = local->hw.wiphy->bands[params->chandef.chan->band];
1766 	for (i = 0; i < sband->n_bitrates; i++) {
1767 		if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
1768 			sdata->u.ibss.basic_rates &= ~BIT(i);
1769 	}
1770 	memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate,
1771 	       sizeof(params->mcast_rate));
1772 
1773 	sdata->vif.bss_conf.beacon_int = params->beacon_interval;
1774 
1775 	sdata->u.ibss.chandef = params->chandef;
1776 	sdata->u.ibss.fixed_channel = params->channel_fixed;
1777 
1778 	if (params->ie) {
1779 		sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
1780 					   GFP_KERNEL);
1781 		if (sdata->u.ibss.ie)
1782 			sdata->u.ibss.ie_len = params->ie_len;
1783 	}
1784 
1785 	sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
1786 	sdata->u.ibss.ibss_join_req = jiffies;
1787 
1788 	memcpy(sdata->u.ibss.ssid, params->ssid, params->ssid_len);
1789 	sdata->u.ibss.ssid_len = params->ssid_len;
1790 
1791 	memcpy(&sdata->u.ibss.ht_capa, &params->ht_capa,
1792 	       sizeof(sdata->u.ibss.ht_capa));
1793 	memcpy(&sdata->u.ibss.ht_capa_mask, &params->ht_capa_mask,
1794 	       sizeof(sdata->u.ibss.ht_capa_mask));
1795 
1796 	/*
1797 	 * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is
1798 	 * reserved, but an HT STA shall protect HT transmissions as though
1799 	 * the HT Protection field were set to non-HT mixed mode.
1800 	 *
1801 	 * In an IBSS, the RIFS Mode field of the HT Operation element is
1802 	 * also reserved, but an HT STA shall operate as though this field
1803 	 * were set to 1.
1804 	 */
1805 
1806 	sdata->vif.bss_conf.ht_operation_mode |=
1807 		  IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED
1808 		| IEEE80211_HT_PARAM_RIFS_MODE;
1809 
1810 	changed |= BSS_CHANGED_HT | BSS_CHANGED_MCAST_RATE;
1811 	ieee80211_link_info_change_notify(sdata, &sdata->deflink, changed);
1812 
1813 	sdata->deflink.smps_mode = IEEE80211_SMPS_OFF;
1814 	sdata->deflink.needed_rx_chains = local->rx_chains;
1815 	sdata->control_port_over_nl80211 = params->control_port_over_nl80211;
1816 
1817 	wiphy_work_queue(local->hw.wiphy, &sdata->work);
1818 
1819 	return 0;
1820 }
1821 
1822 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
1823 {
1824 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1825 
1826 	ieee80211_ibss_disconnect(sdata);
1827 	ifibss->ssid_len = 0;
1828 	eth_zero_addr(ifibss->bssid);
1829 
1830 	/* remove beacon */
1831 	kfree(sdata->u.ibss.ie);
1832 	sdata->u.ibss.ie = NULL;
1833 	sdata->u.ibss.ie_len = 0;
1834 
1835 	/* on the next join, re-program HT parameters */
1836 	memset(&ifibss->ht_capa, 0, sizeof(ifibss->ht_capa));
1837 	memset(&ifibss->ht_capa_mask, 0, sizeof(ifibss->ht_capa_mask));
1838 
1839 	synchronize_rcu();
1840 
1841 	skb_queue_purge(&sdata->skb_queue);
1842 
1843 	del_timer_sync(&sdata->u.ibss.timer);
1844 
1845 	return 0;
1846 }
1847