xref: /linux/net/mac80211/ibss.c (revision 722ecdbce68a87de2d9296f91308f44ea900a039)
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) 2018-2021 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 	int shift;
55 
56 	/* Build IBSS probe response */
57 	frame_len = sizeof(struct ieee80211_hdr_3addr) +
58 		    12 /* struct ieee80211_mgmt.u.beacon */ +
59 		    2 + IEEE80211_MAX_SSID_LEN /* max SSID */ +
60 		    2 + 8 /* max Supported Rates */ +
61 		    3 /* max DS params */ +
62 		    4 /* IBSS params */ +
63 		    5 /* Channel Switch Announcement */ +
64 		    2 + (IEEE80211_MAX_SUPP_RATES - 8) +
65 		    2 + sizeof(struct ieee80211_ht_cap) +
66 		    2 + sizeof(struct ieee80211_ht_operation) +
67 		    2 + sizeof(struct ieee80211_vht_cap) +
68 		    2 + sizeof(struct ieee80211_vht_operation) +
69 		    ifibss->ie_len;
70 	presp = kzalloc(sizeof(*presp) + frame_len, GFP_KERNEL);
71 	if (!presp)
72 		return NULL;
73 
74 	presp->head = (void *)(presp + 1);
75 
76 	mgmt = (void *) presp->head;
77 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
78 					  IEEE80211_STYPE_PROBE_RESP);
79 	eth_broadcast_addr(mgmt->da);
80 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
81 	memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
82 	mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
83 	mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
84 	mgmt->u.beacon.capab_info = cpu_to_le16(capability);
85 
86 	pos = (u8 *)mgmt + offsetof(struct ieee80211_mgmt, u.beacon.variable);
87 
88 	*pos++ = WLAN_EID_SSID;
89 	*pos++ = ifibss->ssid_len;
90 	memcpy(pos, ifibss->ssid, ifibss->ssid_len);
91 	pos += ifibss->ssid_len;
92 
93 	sband = local->hw.wiphy->bands[chandef->chan->band];
94 	rate_flags = ieee80211_chandef_rate_flags(chandef);
95 	shift = ieee80211_chandef_get_shift(chandef);
96 	rates_n = 0;
97 	if (have_higher_than_11mbit)
98 		*have_higher_than_11mbit = false;
99 
100 	for (i = 0; i < sband->n_bitrates; i++) {
101 		if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
102 			continue;
103 		if (sband->bitrates[i].bitrate > 110 &&
104 		    have_higher_than_11mbit)
105 			*have_higher_than_11mbit = true;
106 
107 		rates |= BIT(i);
108 		rates_n++;
109 	}
110 
111 	*pos++ = WLAN_EID_SUPP_RATES;
112 	*pos++ = min_t(int, 8, rates_n);
113 	for (ri = 0; ri < sband->n_bitrates; ri++) {
114 		int rate = DIV_ROUND_UP(sband->bitrates[ri].bitrate,
115 					5 * (1 << shift));
116 		u8 basic = 0;
117 		if (!(rates & BIT(ri)))
118 			continue;
119 
120 		if (basic_rates & BIT(ri))
121 			basic = 0x80;
122 		*pos++ = basic | (u8) rate;
123 		if (++rates_added == 8) {
124 			ri++; /* continue at next rate for EXT_SUPP_RATES */
125 			break;
126 		}
127 	}
128 
129 	if (sband->band == NL80211_BAND_2GHZ) {
130 		*pos++ = WLAN_EID_DS_PARAMS;
131 		*pos++ = 1;
132 		*pos++ = ieee80211_frequency_to_channel(
133 				chandef->chan->center_freq);
134 	}
135 
136 	*pos++ = WLAN_EID_IBSS_PARAMS;
137 	*pos++ = 2;
138 	/* FIX: set ATIM window based on scan results */
139 	*pos++ = 0;
140 	*pos++ = 0;
141 
142 	if (csa_settings) {
143 		*pos++ = WLAN_EID_CHANNEL_SWITCH;
144 		*pos++ = 3;
145 		*pos++ = csa_settings->block_tx ? 1 : 0;
146 		*pos++ = ieee80211_frequency_to_channel(
147 				csa_settings->chandef.chan->center_freq);
148 		presp->cntdwn_counter_offsets[0] = (pos - presp->head);
149 		*pos++ = csa_settings->count;
150 		presp->cntdwn_current_counter = csa_settings->count;
151 	}
152 
153 	/* put the remaining rates in WLAN_EID_EXT_SUPP_RATES */
154 	if (rates_n > 8) {
155 		*pos++ = WLAN_EID_EXT_SUPP_RATES;
156 		*pos++ = rates_n - 8;
157 		for (; ri < sband->n_bitrates; ri++) {
158 			int rate = DIV_ROUND_UP(sband->bitrates[ri].bitrate,
159 						5 * (1 << shift));
160 			u8 basic = 0;
161 			if (!(rates & BIT(ri)))
162 				continue;
163 
164 			if (basic_rates & BIT(ri))
165 				basic = 0x80;
166 			*pos++ = basic | (u8) rate;
167 		}
168 	}
169 
170 	if (ifibss->ie_len) {
171 		memcpy(pos, ifibss->ie, ifibss->ie_len);
172 		pos += ifibss->ie_len;
173 	}
174 
175 	/* add HT capability and information IEs */
176 	if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT &&
177 	    chandef->width != NL80211_CHAN_WIDTH_5 &&
178 	    chandef->width != NL80211_CHAN_WIDTH_10 &&
179 	    sband->ht_cap.ht_supported) {
180 		struct ieee80211_sta_ht_cap ht_cap;
181 
182 		memcpy(&ht_cap, &sband->ht_cap, sizeof(ht_cap));
183 		ieee80211_apply_htcap_overrides(sdata, &ht_cap);
184 
185 		pos = ieee80211_ie_build_ht_cap(pos, &ht_cap, ht_cap.cap);
186 		/*
187 		 * Note: According to 802.11n-2009 9.13.3.1, HT Protection
188 		 * field and RIFS Mode are reserved in IBSS mode, therefore
189 		 * keep them at 0
190 		 */
191 		pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap,
192 						 chandef, 0, false);
193 
194 		/* add VHT capability and information IEs */
195 		if (chandef->width != NL80211_CHAN_WIDTH_20 &&
196 		    chandef->width != NL80211_CHAN_WIDTH_40 &&
197 		    sband->vht_cap.vht_supported) {
198 			pos = ieee80211_ie_build_vht_cap(pos, &sband->vht_cap,
199 							 sband->vht_cap.cap);
200 			pos = ieee80211_ie_build_vht_oper(pos, &sband->vht_cap,
201 							  chandef);
202 		}
203 	}
204 
205 	if (local->hw.queues >= IEEE80211_NUM_ACS)
206 		pos = ieee80211_add_wmm_info_ie(pos, 0); /* U-APSD not in use */
207 
208 	presp->head_len = pos - presp->head;
209 	if (WARN_ON(presp->head_len > frame_len))
210 		goto error;
211 
212 	return presp;
213 error:
214 	kfree(presp);
215 	return NULL;
216 }
217 
218 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
219 				      const u8 *bssid, const int beacon_int,
220 				      struct cfg80211_chan_def *req_chandef,
221 				      const u32 basic_rates,
222 				      const u16 capability, u64 tsf,
223 				      bool creator)
224 {
225 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
226 	struct ieee80211_local *local = sdata->local;
227 	struct ieee80211_mgmt *mgmt;
228 	struct cfg80211_bss *bss;
229 	u32 bss_change;
230 	struct cfg80211_chan_def chandef;
231 	struct ieee80211_channel *chan;
232 	struct beacon_data *presp;
233 	struct cfg80211_inform_bss bss_meta = {};
234 	bool have_higher_than_11mbit;
235 	bool radar_required;
236 	int err;
237 
238 	sdata_assert_lock(sdata);
239 
240 	/* Reset own TSF to allow time synchronization work. */
241 	drv_reset_tsf(local, sdata);
242 
243 	if (!ether_addr_equal(ifibss->bssid, bssid))
244 		sta_info_flush(sdata);
245 
246 	/* if merging, indicate to driver that we leave the old IBSS */
247 	if (sdata->vif.bss_conf.ibss_joined) {
248 		sdata->vif.bss_conf.ibss_joined = false;
249 		sdata->vif.bss_conf.ibss_creator = false;
250 		sdata->vif.bss_conf.enable_beacon = false;
251 		netif_carrier_off(sdata->dev);
252 		ieee80211_bss_info_change_notify(sdata,
253 						 BSS_CHANGED_IBSS |
254 						 BSS_CHANGED_BEACON_ENABLED);
255 		drv_leave_ibss(local, sdata);
256 	}
257 
258 	presp = rcu_dereference_protected(ifibss->presp,
259 					  lockdep_is_held(&sdata->wdev.mtx));
260 	RCU_INIT_POINTER(ifibss->presp, NULL);
261 	if (presp)
262 		kfree_rcu(presp, rcu_head);
263 
264 	/* make a copy of the chandef, it could be modified below. */
265 	chandef = *req_chandef;
266 	chan = chandef.chan;
267 	if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef,
268 				     NL80211_IFTYPE_ADHOC)) {
269 		if (chandef.width == NL80211_CHAN_WIDTH_5 ||
270 		    chandef.width == NL80211_CHAN_WIDTH_10 ||
271 		    chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
272 		    chandef.width == NL80211_CHAN_WIDTH_20) {
273 			sdata_info(sdata,
274 				   "Failed to join IBSS, beacons forbidden\n");
275 			return;
276 		}
277 		chandef.width = NL80211_CHAN_WIDTH_20;
278 		chandef.center_freq1 = chan->center_freq;
279 		/* check again for downgraded chandef */
280 		if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef,
281 					     NL80211_IFTYPE_ADHOC)) {
282 			sdata_info(sdata,
283 				   "Failed to join IBSS, beacons forbidden\n");
284 			return;
285 		}
286 	}
287 
288 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
289 					    &chandef, NL80211_IFTYPE_ADHOC);
290 	if (err < 0) {
291 		sdata_info(sdata,
292 			   "Failed to join IBSS, invalid chandef\n");
293 		return;
294 	}
295 	if (err > 0 && !ifibss->userspace_handles_dfs) {
296 		sdata_info(sdata,
297 			   "Failed to join IBSS, DFS channel without control program\n");
298 		return;
299 	}
300 
301 	radar_required = err;
302 
303 	mutex_lock(&local->mtx);
304 	if (ieee80211_vif_use_channel(sdata, &chandef,
305 				      ifibss->fixed_channel ?
306 					IEEE80211_CHANCTX_SHARED :
307 					IEEE80211_CHANCTX_EXCLUSIVE)) {
308 		sdata_info(sdata, "Failed to join IBSS, no channel context\n");
309 		mutex_unlock(&local->mtx);
310 		return;
311 	}
312 	sdata->radar_required = radar_required;
313 	mutex_unlock(&local->mtx);
314 
315 	memcpy(ifibss->bssid, bssid, ETH_ALEN);
316 
317 	presp = ieee80211_ibss_build_presp(sdata, beacon_int, basic_rates,
318 					   capability, tsf, &chandef,
319 					   &have_higher_than_11mbit, NULL);
320 	if (!presp)
321 		return;
322 
323 	rcu_assign_pointer(ifibss->presp, presp);
324 	mgmt = (void *)presp->head;
325 
326 	sdata->vif.bss_conf.enable_beacon = true;
327 	sdata->vif.bss_conf.beacon_int = beacon_int;
328 	sdata->vif.bss_conf.basic_rates = basic_rates;
329 	sdata->vif.bss_conf.ssid_len = ifibss->ssid_len;
330 	memcpy(sdata->vif.bss_conf.ssid, ifibss->ssid, ifibss->ssid_len);
331 	bss_change = BSS_CHANGED_BEACON_INT;
332 	bss_change |= ieee80211_reset_erp_info(sdata);
333 	bss_change |= BSS_CHANGED_BSSID;
334 	bss_change |= BSS_CHANGED_BEACON;
335 	bss_change |= BSS_CHANGED_BEACON_ENABLED;
336 	bss_change |= BSS_CHANGED_BASIC_RATES;
337 	bss_change |= BSS_CHANGED_HT;
338 	bss_change |= BSS_CHANGED_IBSS;
339 	bss_change |= BSS_CHANGED_SSID;
340 
341 	/*
342 	 * In 5 GHz/802.11a, we can always use short slot time.
343 	 * (IEEE 802.11-2012 18.3.8.7)
344 	 *
345 	 * In 2.4GHz, we must always use long slots in IBSS for compatibility
346 	 * reasons.
347 	 * (IEEE 802.11-2012 19.4.5)
348 	 *
349 	 * HT follows these specifications (IEEE 802.11-2012 20.3.18)
350 	 */
351 	sdata->vif.bss_conf.use_short_slot = chan->band == NL80211_BAND_5GHZ;
352 	bss_change |= BSS_CHANGED_ERP_SLOT;
353 
354 	/* cf. IEEE 802.11 9.2.12 */
355 	if (chan->band == NL80211_BAND_2GHZ && have_higher_than_11mbit)
356 		sdata->flags |= IEEE80211_SDATA_OPERATING_GMODE;
357 	else
358 		sdata->flags &= ~IEEE80211_SDATA_OPERATING_GMODE;
359 
360 	ieee80211_set_wmm_default(sdata, true, false);
361 
362 	sdata->vif.bss_conf.ibss_joined = true;
363 	sdata->vif.bss_conf.ibss_creator = creator;
364 
365 	err = drv_join_ibss(local, sdata);
366 	if (err) {
367 		sdata->vif.bss_conf.ibss_joined = false;
368 		sdata->vif.bss_conf.ibss_creator = false;
369 		sdata->vif.bss_conf.enable_beacon = false;
370 		sdata->vif.bss_conf.ssid_len = 0;
371 		RCU_INIT_POINTER(ifibss->presp, NULL);
372 		kfree_rcu(presp, rcu_head);
373 		mutex_lock(&local->mtx);
374 		ieee80211_vif_release_channel(sdata);
375 		mutex_unlock(&local->mtx);
376 		sdata_info(sdata, "Failed to join IBSS, driver failure: %d\n",
377 			   err);
378 		return;
379 	}
380 
381 	ieee80211_bss_info_change_notify(sdata, bss_change);
382 
383 	ifibss->state = IEEE80211_IBSS_MLME_JOINED;
384 	mod_timer(&ifibss->timer,
385 		  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
386 
387 	bss_meta.chan = chan;
388 	bss_meta.scan_width = cfg80211_chandef_to_scan_width(&chandef);
389 	bss = cfg80211_inform_bss_frame_data(local->hw.wiphy, &bss_meta, mgmt,
390 					     presp->head_len, GFP_KERNEL);
391 
392 	cfg80211_put_bss(local->hw.wiphy, bss);
393 	netif_carrier_on(sdata->dev);
394 	cfg80211_ibss_joined(sdata->dev, ifibss->bssid, chan, GFP_KERNEL);
395 }
396 
397 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
398 				    struct ieee80211_bss *bss)
399 {
400 	struct cfg80211_bss *cbss =
401 		container_of((void *)bss, struct cfg80211_bss, priv);
402 	struct ieee80211_supported_band *sband;
403 	struct cfg80211_chan_def chandef;
404 	u32 basic_rates;
405 	int i, j;
406 	u16 beacon_int = cbss->beacon_interval;
407 	const struct cfg80211_bss_ies *ies;
408 	enum nl80211_channel_type chan_type;
409 	u64 tsf;
410 	u32 rate_flags;
411 	int shift;
412 
413 	sdata_assert_lock(sdata);
414 
415 	if (beacon_int < 10)
416 		beacon_int = 10;
417 
418 	switch (sdata->u.ibss.chandef.width) {
419 	case NL80211_CHAN_WIDTH_20_NOHT:
420 	case NL80211_CHAN_WIDTH_20:
421 	case NL80211_CHAN_WIDTH_40:
422 		chan_type = cfg80211_get_chandef_type(&sdata->u.ibss.chandef);
423 		cfg80211_chandef_create(&chandef, cbss->channel, chan_type);
424 		break;
425 	case NL80211_CHAN_WIDTH_5:
426 	case NL80211_CHAN_WIDTH_10:
427 		cfg80211_chandef_create(&chandef, cbss->channel,
428 					NL80211_CHAN_NO_HT);
429 		chandef.width = sdata->u.ibss.chandef.width;
430 		break;
431 	case NL80211_CHAN_WIDTH_80:
432 	case NL80211_CHAN_WIDTH_80P80:
433 	case NL80211_CHAN_WIDTH_160:
434 		chandef = sdata->u.ibss.chandef;
435 		chandef.chan = cbss->channel;
436 		break;
437 	default:
438 		/* fall back to 20 MHz for unsupported modes */
439 		cfg80211_chandef_create(&chandef, cbss->channel,
440 					NL80211_CHAN_NO_HT);
441 		break;
442 	}
443 
444 	sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
445 	rate_flags = ieee80211_chandef_rate_flags(&sdata->u.ibss.chandef);
446 	shift = ieee80211_vif_get_shift(&sdata->vif);
447 
448 	basic_rates = 0;
449 
450 	for (i = 0; i < bss->supp_rates_len; i++) {
451 		int rate = bss->supp_rates[i] & 0x7f;
452 		bool is_basic = !!(bss->supp_rates[i] & 0x80);
453 
454 		for (j = 0; j < sband->n_bitrates; j++) {
455 			int brate;
456 			if ((rate_flags & sband->bitrates[j].flags)
457 			    != rate_flags)
458 				continue;
459 
460 			brate = DIV_ROUND_UP(sband->bitrates[j].bitrate,
461 					     5 * (1 << shift));
462 			if (brate == rate) {
463 				if (is_basic)
464 					basic_rates |= BIT(j);
465 				break;
466 			}
467 		}
468 	}
469 
470 	rcu_read_lock();
471 	ies = rcu_dereference(cbss->ies);
472 	tsf = ies->tsf;
473 	rcu_read_unlock();
474 
475 	__ieee80211_sta_join_ibss(sdata, cbss->bssid,
476 				  beacon_int,
477 				  &chandef,
478 				  basic_rates,
479 				  cbss->capability,
480 				  tsf, false);
481 }
482 
483 int ieee80211_ibss_csa_beacon(struct ieee80211_sub_if_data *sdata,
484 			      struct cfg80211_csa_settings *csa_settings)
485 {
486 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
487 	struct beacon_data *presp, *old_presp;
488 	struct cfg80211_bss *cbss;
489 	const struct cfg80211_bss_ies *ies;
490 	u16 capability = WLAN_CAPABILITY_IBSS;
491 	u64 tsf;
492 
493 	sdata_assert_lock(sdata);
494 
495 	if (ifibss->privacy)
496 		capability |= WLAN_CAPABILITY_PRIVACY;
497 
498 	cbss = cfg80211_get_bss(sdata->local->hw.wiphy, ifibss->chandef.chan,
499 				ifibss->bssid, ifibss->ssid,
500 				ifibss->ssid_len, IEEE80211_BSS_TYPE_IBSS,
501 				IEEE80211_PRIVACY(ifibss->privacy));
502 
503 	if (WARN_ON(!cbss))
504 		return -EINVAL;
505 
506 	rcu_read_lock();
507 	ies = rcu_dereference(cbss->ies);
508 	tsf = ies->tsf;
509 	rcu_read_unlock();
510 	cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
511 
512 	old_presp = rcu_dereference_protected(ifibss->presp,
513 					  lockdep_is_held(&sdata->wdev.mtx));
514 
515 	presp = ieee80211_ibss_build_presp(sdata,
516 					   sdata->vif.bss_conf.beacon_int,
517 					   sdata->vif.bss_conf.basic_rates,
518 					   capability, tsf, &ifibss->chandef,
519 					   NULL, csa_settings);
520 	if (!presp)
521 		return -ENOMEM;
522 
523 	rcu_assign_pointer(ifibss->presp, presp);
524 	if (old_presp)
525 		kfree_rcu(old_presp, rcu_head);
526 
527 	return BSS_CHANGED_BEACON;
528 }
529 
530 int ieee80211_ibss_finish_csa(struct ieee80211_sub_if_data *sdata)
531 {
532 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
533 	struct cfg80211_bss *cbss;
534 
535 	sdata_assert_lock(sdata);
536 
537 	/* update cfg80211 bss information with the new channel */
538 	if (!is_zero_ether_addr(ifibss->bssid)) {
539 		cbss = cfg80211_get_bss(sdata->local->hw.wiphy,
540 					ifibss->chandef.chan,
541 					ifibss->bssid, ifibss->ssid,
542 					ifibss->ssid_len,
543 					IEEE80211_BSS_TYPE_IBSS,
544 					IEEE80211_PRIVACY(ifibss->privacy));
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 	return ieee80211_ibss_csa_beacon(sdata, NULL);
556 }
557 
558 void ieee80211_ibss_stop(struct ieee80211_sub_if_data *sdata)
559 {
560 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
561 
562 	cancel_work_sync(&ifibss->csa_connection_drop_work);
563 }
564 
565 static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta)
566 	__acquires(RCU)
567 {
568 	struct ieee80211_sub_if_data *sdata = sta->sdata;
569 	u8 addr[ETH_ALEN];
570 
571 	memcpy(addr, sta->sta.addr, ETH_ALEN);
572 
573 	ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr);
574 
575 	sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
576 	sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
577 	/* authorize the station only if the network is not RSN protected. If
578 	 * not wait for the userspace to authorize it */
579 	if (!sta->sdata->u.ibss.control_port)
580 		sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
581 
582 	rate_control_rate_init(sta);
583 
584 	/* If it fails, maybe we raced another insertion? */
585 	if (sta_info_insert_rcu(sta))
586 		return sta_info_get(sdata, addr);
587 	return sta;
588 }
589 
590 static struct sta_info *
591 ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, const u8 *bssid,
592 		       const u8 *addr, u32 supp_rates)
593 	__acquires(RCU)
594 {
595 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
596 	struct ieee80211_local *local = sdata->local;
597 	struct sta_info *sta;
598 	struct ieee80211_chanctx_conf *chanctx_conf;
599 	struct ieee80211_supported_band *sband;
600 	enum nl80211_bss_scan_width scan_width;
601 	int band;
602 
603 	/*
604 	 * XXX: Consider removing the least recently used entry and
605 	 * 	allow new one to be added.
606 	 */
607 	if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
608 		net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
609 				    sdata->name, addr);
610 		rcu_read_lock();
611 		return NULL;
612 	}
613 
614 	if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) {
615 		rcu_read_lock();
616 		return NULL;
617 	}
618 
619 	if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) {
620 		rcu_read_lock();
621 		return NULL;
622 	}
623 
624 	rcu_read_lock();
625 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
626 	if (WARN_ON_ONCE(!chanctx_conf))
627 		return NULL;
628 	band = chanctx_conf->def.chan->band;
629 	scan_width = cfg80211_chandef_to_scan_width(&chanctx_conf->def);
630 	rcu_read_unlock();
631 
632 	sta = sta_info_alloc(sdata, addr, GFP_KERNEL);
633 	if (!sta) {
634 		rcu_read_lock();
635 		return NULL;
636 	}
637 
638 	/* make sure mandatory rates are always added */
639 	sband = local->hw.wiphy->bands[band];
640 	sta->sta.deflink.supp_rates[band] = supp_rates |
641 			ieee80211_mandatory_rates(sband, scan_width);
642 
643 	return ieee80211_ibss_finish_sta(sta);
644 }
645 
646 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
647 {
648 	struct ieee80211_local *local = sdata->local;
649 	int active = 0;
650 	struct sta_info *sta;
651 
652 	sdata_assert_lock(sdata);
653 
654 	rcu_read_lock();
655 
656 	list_for_each_entry_rcu(sta, &local->sta_list, list) {
657 		unsigned long last_active = ieee80211_sta_last_active(sta);
658 
659 		if (sta->sdata == sdata &&
660 		    time_is_after_jiffies(last_active +
661 					  IEEE80211_IBSS_MERGE_INTERVAL)) {
662 			active++;
663 			break;
664 		}
665 	}
666 
667 	rcu_read_unlock();
668 
669 	return active;
670 }
671 
672 static void ieee80211_ibss_disconnect(struct ieee80211_sub_if_data *sdata)
673 {
674 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
675 	struct ieee80211_local *local = sdata->local;
676 	struct cfg80211_bss *cbss;
677 	struct beacon_data *presp;
678 	struct sta_info *sta;
679 
680 	if (!is_zero_ether_addr(ifibss->bssid)) {
681 		cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->chandef.chan,
682 					ifibss->bssid, ifibss->ssid,
683 					ifibss->ssid_len,
684 					IEEE80211_BSS_TYPE_IBSS,
685 					IEEE80211_PRIVACY(ifibss->privacy));
686 
687 		if (cbss) {
688 			cfg80211_unlink_bss(local->hw.wiphy, cbss);
689 			cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
690 		}
691 	}
692 
693 	ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
694 
695 	sta_info_flush(sdata);
696 
697 	spin_lock_bh(&ifibss->incomplete_lock);
698 	while (!list_empty(&ifibss->incomplete_stations)) {
699 		sta = list_first_entry(&ifibss->incomplete_stations,
700 				       struct sta_info, list);
701 		list_del(&sta->list);
702 		spin_unlock_bh(&ifibss->incomplete_lock);
703 
704 		sta_info_free(local, sta);
705 		spin_lock_bh(&ifibss->incomplete_lock);
706 	}
707 	spin_unlock_bh(&ifibss->incomplete_lock);
708 
709 	netif_carrier_off(sdata->dev);
710 
711 	sdata->vif.bss_conf.ibss_joined = false;
712 	sdata->vif.bss_conf.ibss_creator = false;
713 	sdata->vif.bss_conf.enable_beacon = false;
714 	sdata->vif.bss_conf.ssid_len = 0;
715 
716 	/* remove beacon */
717 	presp = rcu_dereference_protected(ifibss->presp,
718 					  lockdep_is_held(&sdata->wdev.mtx));
719 	RCU_INIT_POINTER(sdata->u.ibss.presp, NULL);
720 	if (presp)
721 		kfree_rcu(presp, rcu_head);
722 
723 	clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
724 	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
725 						BSS_CHANGED_IBSS);
726 	drv_leave_ibss(local, sdata);
727 	mutex_lock(&local->mtx);
728 	ieee80211_vif_release_channel(sdata);
729 	mutex_unlock(&local->mtx);
730 }
731 
732 static void ieee80211_csa_connection_drop_work(struct work_struct *work)
733 {
734 	struct ieee80211_sub_if_data *sdata =
735 		container_of(work, struct ieee80211_sub_if_data,
736 			     u.ibss.csa_connection_drop_work);
737 
738 	sdata_lock(sdata);
739 
740 	ieee80211_ibss_disconnect(sdata);
741 	synchronize_rcu();
742 	skb_queue_purge(&sdata->skb_queue);
743 
744 	/* trigger a scan to find another IBSS network to join */
745 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
746 
747 	sdata_unlock(sdata);
748 }
749 
750 static void ieee80211_ibss_csa_mark_radar(struct ieee80211_sub_if_data *sdata)
751 {
752 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
753 	int err;
754 
755 	/* if the current channel is a DFS channel, mark the channel as
756 	 * unavailable.
757 	 */
758 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
759 					    &ifibss->chandef,
760 					    NL80211_IFTYPE_ADHOC);
761 	if (err > 0)
762 		cfg80211_radar_event(sdata->local->hw.wiphy, &ifibss->chandef,
763 				     GFP_ATOMIC);
764 }
765 
766 static bool
767 ieee80211_ibss_process_chanswitch(struct ieee80211_sub_if_data *sdata,
768 				  struct ieee802_11_elems *elems,
769 				  bool beacon)
770 {
771 	struct cfg80211_csa_settings params;
772 	struct ieee80211_csa_ie csa_ie;
773 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
774 	enum nl80211_channel_type ch_type;
775 	int err;
776 	u32 sta_flags;
777 	u32 vht_cap_info = 0;
778 
779 	sdata_assert_lock(sdata);
780 
781 	sta_flags = IEEE80211_STA_DISABLE_VHT;
782 	switch (ifibss->chandef.width) {
783 	case NL80211_CHAN_WIDTH_5:
784 	case NL80211_CHAN_WIDTH_10:
785 	case NL80211_CHAN_WIDTH_20_NOHT:
786 		sta_flags |= IEEE80211_STA_DISABLE_HT;
787 		fallthrough;
788 	case NL80211_CHAN_WIDTH_20:
789 		sta_flags |= IEEE80211_STA_DISABLE_40MHZ;
790 		break;
791 	default:
792 		break;
793 	}
794 
795 	if (elems->vht_cap_elem)
796 		vht_cap_info = le32_to_cpu(elems->vht_cap_elem->vht_cap_info);
797 
798 	memset(&params, 0, sizeof(params));
799 	err = ieee80211_parse_ch_switch_ie(sdata, elems,
800 					   ifibss->chandef.chan->band,
801 					   vht_cap_info,
802 					   sta_flags, ifibss->bssid, &csa_ie);
803 	/* can't switch to destination channel, fail */
804 	if (err < 0)
805 		goto disconnect;
806 
807 	/* did not contain a CSA */
808 	if (err)
809 		return false;
810 
811 	/* channel switch is not supported, disconnect */
812 	if (!(sdata->local->hw.wiphy->flags & WIPHY_FLAG_HAS_CHANNEL_SWITCH))
813 		goto disconnect;
814 
815 	params.count = csa_ie.count;
816 	params.chandef = csa_ie.chandef;
817 
818 	switch (ifibss->chandef.width) {
819 	case NL80211_CHAN_WIDTH_20_NOHT:
820 	case NL80211_CHAN_WIDTH_20:
821 	case NL80211_CHAN_WIDTH_40:
822 		/* keep our current HT mode (HT20/HT40+/HT40-), even if
823 		 * another mode  has been announced. The mode is not adopted
824 		 * within the beacon while doing CSA and we should therefore
825 		 * keep the mode which we announce.
826 		 */
827 		ch_type = cfg80211_get_chandef_type(&ifibss->chandef);
828 		cfg80211_chandef_create(&params.chandef, params.chandef.chan,
829 					ch_type);
830 		break;
831 	case NL80211_CHAN_WIDTH_5:
832 	case NL80211_CHAN_WIDTH_10:
833 		if (params.chandef.width != ifibss->chandef.width) {
834 			sdata_info(sdata,
835 				   "IBSS %pM received channel switch from incompatible channel width (%d MHz, width:%d, CF1/2: %d/%d MHz), disconnecting\n",
836 				   ifibss->bssid,
837 				   params.chandef.chan->center_freq,
838 				   params.chandef.width,
839 				   params.chandef.center_freq1,
840 				   params.chandef.center_freq2);
841 			goto disconnect;
842 		}
843 		break;
844 	default:
845 		/* should not happen, sta_flags should prevent VHT modes. */
846 		WARN_ON(1);
847 		goto disconnect;
848 	}
849 
850 	if (!cfg80211_reg_can_beacon(sdata->local->hw.wiphy, &params.chandef,
851 				     NL80211_IFTYPE_ADHOC)) {
852 		sdata_info(sdata,
853 			   "IBSS %pM switches to unsupported channel (%d MHz, width:%d, CF1/2: %d/%d MHz), disconnecting\n",
854 			   ifibss->bssid,
855 			   params.chandef.chan->center_freq,
856 			   params.chandef.width,
857 			   params.chandef.center_freq1,
858 			   params.chandef.center_freq2);
859 		goto disconnect;
860 	}
861 
862 	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
863 					    &params.chandef,
864 					    NL80211_IFTYPE_ADHOC);
865 	if (err < 0)
866 		goto disconnect;
867 	if (err > 0 && !ifibss->userspace_handles_dfs) {
868 		/* IBSS-DFS only allowed with a control program */
869 		goto disconnect;
870 	}
871 
872 	params.radar_required = err;
873 
874 	if (cfg80211_chandef_identical(&params.chandef,
875 				       &sdata->vif.bss_conf.chandef)) {
876 		ibss_dbg(sdata,
877 			 "received csa with an identical chandef, ignoring\n");
878 		return true;
879 	}
880 
881 	/* all checks done, now perform the channel switch. */
882 	ibss_dbg(sdata,
883 		 "received channel switch announcement to go to channel %d MHz\n",
884 		 params.chandef.chan->center_freq);
885 
886 	params.block_tx = !!csa_ie.mode;
887 
888 	if (ieee80211_channel_switch(sdata->local->hw.wiphy, sdata->dev,
889 				     &params))
890 		goto disconnect;
891 
892 	ieee80211_ibss_csa_mark_radar(sdata);
893 
894 	return true;
895 disconnect:
896 	ibss_dbg(sdata, "Can't handle channel switch, disconnect\n");
897 	ieee80211_queue_work(&sdata->local->hw,
898 			     &ifibss->csa_connection_drop_work);
899 
900 	ieee80211_ibss_csa_mark_radar(sdata);
901 
902 	return true;
903 }
904 
905 static void
906 ieee80211_rx_mgmt_spectrum_mgmt(struct ieee80211_sub_if_data *sdata,
907 				struct ieee80211_mgmt *mgmt, size_t len,
908 				struct ieee80211_rx_status *rx_status,
909 				struct ieee802_11_elems *elems)
910 {
911 	int required_len;
912 
913 	if (len < IEEE80211_MIN_ACTION_SIZE + 1)
914 		return;
915 
916 	/* CSA is the only action we handle for now */
917 	if (mgmt->u.action.u.measurement.action_code !=
918 	    WLAN_ACTION_SPCT_CHL_SWITCH)
919 		return;
920 
921 	required_len = IEEE80211_MIN_ACTION_SIZE +
922 		       sizeof(mgmt->u.action.u.chan_switch);
923 	if (len < required_len)
924 		return;
925 
926 	if (!sdata->vif.csa_active)
927 		ieee80211_ibss_process_chanswitch(sdata, elems, false);
928 }
929 
930 static void ieee80211_rx_mgmt_deauth_ibss(struct ieee80211_sub_if_data *sdata,
931 					  struct ieee80211_mgmt *mgmt,
932 					  size_t len)
933 {
934 	u16 reason = le16_to_cpu(mgmt->u.deauth.reason_code);
935 
936 	if (len < IEEE80211_DEAUTH_FRAME_LEN)
937 		return;
938 
939 	ibss_dbg(sdata, "RX DeAuth SA=%pM DA=%pM\n", mgmt->sa, mgmt->da);
940 	ibss_dbg(sdata, "\tBSSID=%pM (reason: %d)\n", mgmt->bssid, reason);
941 	sta_info_destroy_addr(sdata, mgmt->sa);
942 }
943 
944 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
945 					struct ieee80211_mgmt *mgmt,
946 					size_t len)
947 {
948 	u16 auth_alg, auth_transaction;
949 
950 	sdata_assert_lock(sdata);
951 
952 	if (len < 24 + 6)
953 		return;
954 
955 	auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
956 	auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
957 
958 	ibss_dbg(sdata, "RX Auth SA=%pM DA=%pM\n", mgmt->sa, mgmt->da);
959 	ibss_dbg(sdata, "\tBSSID=%pM (auth_transaction=%d)\n",
960 		 mgmt->bssid, auth_transaction);
961 
962 	if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1)
963 		return;
964 
965 	/*
966 	 * IEEE 802.11 standard does not require authentication in IBSS
967 	 * networks and most implementations do not seem to use it.
968 	 * However, try to reply to authentication attempts if someone
969 	 * has actually implemented this.
970 	 */
971 	ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, 0, NULL, 0,
972 			    mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0, 0);
973 }
974 
975 static void ieee80211_update_sta_info(struct ieee80211_sub_if_data *sdata,
976 				      struct ieee80211_mgmt *mgmt, size_t len,
977 				      struct ieee80211_rx_status *rx_status,
978 				      struct ieee802_11_elems *elems,
979 				      struct ieee80211_channel *channel)
980 {
981 	struct sta_info *sta;
982 	enum nl80211_band band = rx_status->band;
983 	enum nl80211_bss_scan_width scan_width;
984 	struct ieee80211_local *local = sdata->local;
985 	struct ieee80211_supported_band *sband;
986 	bool rates_updated = false;
987 	u32 supp_rates = 0;
988 
989 	if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
990 		return;
991 
992 	if (!ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid))
993 		return;
994 
995 	sband = local->hw.wiphy->bands[band];
996 	if (WARN_ON(!sband))
997 		return;
998 
999 	rcu_read_lock();
1000 	sta = sta_info_get(sdata, mgmt->sa);
1001 
1002 	if (elems->supp_rates) {
1003 		supp_rates = ieee80211_sta_get_rates(sdata, elems,
1004 						     band, NULL);
1005 		if (sta) {
1006 			u32 prev_rates;
1007 
1008 			prev_rates = sta->sta.deflink.supp_rates[band];
1009 			/* make sure mandatory rates are always added */
1010 			scan_width = NL80211_BSS_CHAN_WIDTH_20;
1011 			if (rx_status->bw == RATE_INFO_BW_5)
1012 				scan_width = NL80211_BSS_CHAN_WIDTH_5;
1013 			else if (rx_status->bw == RATE_INFO_BW_10)
1014 				scan_width = NL80211_BSS_CHAN_WIDTH_10;
1015 
1016 			sta->sta.deflink.supp_rates[band] = supp_rates |
1017 				ieee80211_mandatory_rates(sband, scan_width);
1018 			if (sta->sta.deflink.supp_rates[band] != prev_rates) {
1019 				ibss_dbg(sdata,
1020 					 "updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n",
1021 					 sta->sta.addr, prev_rates,
1022 					 sta->sta.deflink.supp_rates[band]);
1023 				rates_updated = true;
1024 			}
1025 		} else {
1026 			rcu_read_unlock();
1027 			sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
1028 						     mgmt->sa, supp_rates);
1029 		}
1030 	}
1031 
1032 	if (sta && !sta->sta.wme &&
1033 	    (elems->wmm_info || elems->s1g_capab) &&
1034 	    local->hw.queues >= IEEE80211_NUM_ACS) {
1035 		sta->sta.wme = true;
1036 		ieee80211_check_fast_xmit(sta);
1037 	}
1038 
1039 	if (sta && elems->ht_operation && elems->ht_cap_elem &&
1040 	    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_20_NOHT &&
1041 	    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_5 &&
1042 	    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_10) {
1043 		/* we both use HT */
1044 		struct ieee80211_ht_cap htcap_ie;
1045 		struct cfg80211_chan_def chandef;
1046 		enum ieee80211_sta_rx_bandwidth bw = sta->sta.deflink.bandwidth;
1047 
1048 		cfg80211_chandef_create(&chandef, channel, NL80211_CHAN_NO_HT);
1049 		ieee80211_chandef_ht_oper(elems->ht_operation, &chandef);
1050 
1051 		memcpy(&htcap_ie, elems->ht_cap_elem, sizeof(htcap_ie));
1052 		rates_updated |= ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
1053 								   &htcap_ie,
1054 								   sta);
1055 
1056 		if (elems->vht_operation && elems->vht_cap_elem &&
1057 		    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_20 &&
1058 		    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_40) {
1059 			/* we both use VHT */
1060 			struct ieee80211_vht_cap cap_ie;
1061 			struct ieee80211_sta_vht_cap cap = sta->sta.deflink.vht_cap;
1062 			u32 vht_cap_info =
1063 				le32_to_cpu(elems->vht_cap_elem->vht_cap_info);
1064 
1065 			ieee80211_chandef_vht_oper(&local->hw, vht_cap_info,
1066 						   elems->vht_operation,
1067 						   elems->ht_operation,
1068 						   &chandef);
1069 			memcpy(&cap_ie, elems->vht_cap_elem, sizeof(cap_ie));
1070 			ieee80211_vht_cap_ie_to_sta_vht_cap(sdata, sband,
1071 							    &cap_ie, sta);
1072 			if (memcmp(&cap, &sta->sta.deflink.vht_cap, sizeof(cap)))
1073 				rates_updated |= true;
1074 		}
1075 
1076 		if (bw != sta->sta.deflink.bandwidth)
1077 			rates_updated |= true;
1078 
1079 		if (!cfg80211_chandef_compatible(&sdata->u.ibss.chandef,
1080 						 &chandef))
1081 			WARN_ON_ONCE(1);
1082 	}
1083 
1084 	if (sta && rates_updated) {
1085 		u32 changed = IEEE80211_RC_SUPP_RATES_CHANGED;
1086 		u8 rx_nss = sta->sta.deflink.rx_nss;
1087 
1088 		/* Force rx_nss recalculation */
1089 		sta->sta.deflink.rx_nss = 0;
1090 		rate_control_rate_init(sta);
1091 		if (sta->sta.deflink.rx_nss != rx_nss)
1092 			changed |= IEEE80211_RC_NSS_CHANGED;
1093 
1094 		drv_sta_rc_update(local, sdata, &sta->sta, changed);
1095 	}
1096 
1097 	rcu_read_unlock();
1098 }
1099 
1100 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
1101 				  struct ieee80211_mgmt *mgmt, size_t len,
1102 				  struct ieee80211_rx_status *rx_status,
1103 				  struct ieee802_11_elems *elems)
1104 {
1105 	struct ieee80211_local *local = sdata->local;
1106 	struct cfg80211_bss *cbss;
1107 	struct ieee80211_bss *bss;
1108 	struct ieee80211_channel *channel;
1109 	u64 beacon_timestamp, rx_timestamp;
1110 	u32 supp_rates = 0;
1111 	enum nl80211_band band = rx_status->band;
1112 
1113 	channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
1114 	if (!channel)
1115 		return;
1116 
1117 	ieee80211_update_sta_info(sdata, mgmt, len, rx_status, elems, channel);
1118 
1119 	bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, channel);
1120 	if (!bss)
1121 		return;
1122 
1123 	cbss = container_of((void *)bss, struct cfg80211_bss, priv);
1124 
1125 	/* same for beacon and probe response */
1126 	beacon_timestamp = le64_to_cpu(mgmt->u.beacon.timestamp);
1127 
1128 	/* check if we need to merge IBSS */
1129 
1130 	/* not an IBSS */
1131 	if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
1132 		goto put_bss;
1133 
1134 	/* different channel */
1135 	if (sdata->u.ibss.fixed_channel &&
1136 	    sdata->u.ibss.chandef.chan != cbss->channel)
1137 		goto put_bss;
1138 
1139 	/* different SSID */
1140 	if (elems->ssid_len != sdata->u.ibss.ssid_len ||
1141 	    memcmp(elems->ssid, sdata->u.ibss.ssid,
1142 				sdata->u.ibss.ssid_len))
1143 		goto put_bss;
1144 
1145 	/* process channel switch */
1146 	if (sdata->vif.csa_active ||
1147 	    ieee80211_ibss_process_chanswitch(sdata, elems, true))
1148 		goto put_bss;
1149 
1150 	/* same BSSID */
1151 	if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid))
1152 		goto put_bss;
1153 
1154 	/* we use a fixed BSSID */
1155 	if (sdata->u.ibss.fixed_bssid)
1156 		goto put_bss;
1157 
1158 	if (ieee80211_have_rx_timestamp(rx_status)) {
1159 		/* time when timestamp field was received */
1160 		rx_timestamp =
1161 			ieee80211_calculate_rx_timestamp(local, rx_status,
1162 							 len + FCS_LEN, 24);
1163 	} else {
1164 		/*
1165 		 * second best option: get current TSF
1166 		 * (will return -1 if not supported)
1167 		 */
1168 		rx_timestamp = drv_get_tsf(local, sdata);
1169 	}
1170 
1171 	ibss_dbg(sdata, "RX beacon SA=%pM BSSID=%pM TSF=0x%llx\n",
1172 		 mgmt->sa, mgmt->bssid,
1173 		 (unsigned long long)rx_timestamp);
1174 	ibss_dbg(sdata, "\tBCN=0x%llx diff=%lld @%lu\n",
1175 		 (unsigned long long)beacon_timestamp,
1176 		 (unsigned long long)(rx_timestamp - beacon_timestamp),
1177 		 jiffies);
1178 
1179 	if (beacon_timestamp > rx_timestamp) {
1180 		ibss_dbg(sdata,
1181 			 "beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n",
1182 			 mgmt->bssid);
1183 		ieee80211_sta_join_ibss(sdata, bss);
1184 		supp_rates = ieee80211_sta_get_rates(sdata, elems, band, NULL);
1185 		ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
1186 				       supp_rates);
1187 		rcu_read_unlock();
1188 	}
1189 
1190  put_bss:
1191 	ieee80211_rx_bss_put(local, bss);
1192 }
1193 
1194 void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata,
1195 			      const u8 *bssid, const u8 *addr,
1196 			      u32 supp_rates)
1197 {
1198 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1199 	struct ieee80211_local *local = sdata->local;
1200 	struct sta_info *sta;
1201 	struct ieee80211_chanctx_conf *chanctx_conf;
1202 	struct ieee80211_supported_band *sband;
1203 	enum nl80211_bss_scan_width scan_width;
1204 	int band;
1205 
1206 	/*
1207 	 * XXX: Consider removing the least recently used entry and
1208 	 * 	allow new one to be added.
1209 	 */
1210 	if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
1211 		net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
1212 				    sdata->name, addr);
1213 		return;
1214 	}
1215 
1216 	if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
1217 		return;
1218 
1219 	if (!ether_addr_equal(bssid, sdata->u.ibss.bssid))
1220 		return;
1221 
1222 	rcu_read_lock();
1223 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
1224 	if (WARN_ON_ONCE(!chanctx_conf)) {
1225 		rcu_read_unlock();
1226 		return;
1227 	}
1228 	band = chanctx_conf->def.chan->band;
1229 	scan_width = cfg80211_chandef_to_scan_width(&chanctx_conf->def);
1230 	rcu_read_unlock();
1231 
1232 	sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
1233 	if (!sta)
1234 		return;
1235 
1236 	/* make sure mandatory rates are always added */
1237 	sband = local->hw.wiphy->bands[band];
1238 	sta->sta.deflink.supp_rates[band] = supp_rates |
1239 			ieee80211_mandatory_rates(sband, scan_width);
1240 
1241 	spin_lock(&ifibss->incomplete_lock);
1242 	list_add(&sta->list, &ifibss->incomplete_stations);
1243 	spin_unlock(&ifibss->incomplete_lock);
1244 	ieee80211_queue_work(&local->hw, &sdata->work);
1245 }
1246 
1247 static void ieee80211_ibss_sta_expire(struct ieee80211_sub_if_data *sdata)
1248 {
1249 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1250 	struct ieee80211_local *local = sdata->local;
1251 	struct sta_info *sta, *tmp;
1252 	unsigned long exp_time = IEEE80211_IBSS_INACTIVITY_LIMIT;
1253 	unsigned long exp_rsn = IEEE80211_IBSS_RSN_INACTIVITY_LIMIT;
1254 
1255 	mutex_lock(&local->sta_mtx);
1256 
1257 	list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
1258 		unsigned long last_active = ieee80211_sta_last_active(sta);
1259 
1260 		if (sdata != sta->sdata)
1261 			continue;
1262 
1263 		if (time_is_before_jiffies(last_active + exp_time) ||
1264 		    (time_is_before_jiffies(last_active + exp_rsn) &&
1265 		     sta->sta_state != IEEE80211_STA_AUTHORIZED)) {
1266 			u8 frame_buf[IEEE80211_DEAUTH_FRAME_LEN];
1267 
1268 			sta_dbg(sta->sdata, "expiring inactive %sSTA %pM\n",
1269 				sta->sta_state != IEEE80211_STA_AUTHORIZED ?
1270 				"not authorized " : "", sta->sta.addr);
1271 
1272 			ieee80211_send_deauth_disassoc(sdata, sta->sta.addr,
1273 						       ifibss->bssid,
1274 						       IEEE80211_STYPE_DEAUTH,
1275 						       WLAN_REASON_DEAUTH_LEAVING,
1276 						       true, frame_buf);
1277 			WARN_ON(__sta_info_destroy(sta));
1278 		}
1279 	}
1280 
1281 	mutex_unlock(&local->sta_mtx);
1282 }
1283 
1284 /*
1285  * This function is called with state == IEEE80211_IBSS_MLME_JOINED
1286  */
1287 
1288 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
1289 {
1290 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1291 	enum nl80211_bss_scan_width scan_width;
1292 
1293 	sdata_assert_lock(sdata);
1294 
1295 	mod_timer(&ifibss->timer,
1296 		  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
1297 
1298 	ieee80211_ibss_sta_expire(sdata);
1299 
1300 	if (time_before(jiffies, ifibss->last_scan_completed +
1301 		       IEEE80211_IBSS_MERGE_INTERVAL))
1302 		return;
1303 
1304 	if (ieee80211_sta_active_ibss(sdata))
1305 		return;
1306 
1307 	if (ifibss->fixed_channel)
1308 		return;
1309 
1310 	sdata_info(sdata,
1311 		   "No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n");
1312 
1313 	scan_width = cfg80211_chandef_to_scan_width(&ifibss->chandef);
1314 	ieee80211_request_ibss_scan(sdata, ifibss->ssid, ifibss->ssid_len,
1315 				    NULL, 0, scan_width);
1316 }
1317 
1318 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
1319 {
1320 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1321 	u8 bssid[ETH_ALEN];
1322 	u16 capability;
1323 	int i;
1324 
1325 	sdata_assert_lock(sdata);
1326 
1327 	if (ifibss->fixed_bssid) {
1328 		memcpy(bssid, ifibss->bssid, ETH_ALEN);
1329 	} else {
1330 		/* Generate random, not broadcast, locally administered BSSID. Mix in
1331 		 * own MAC address to make sure that devices that do not have proper
1332 		 * random number generator get different BSSID. */
1333 		get_random_bytes(bssid, ETH_ALEN);
1334 		for (i = 0; i < ETH_ALEN; i++)
1335 			bssid[i] ^= sdata->vif.addr[i];
1336 		bssid[0] &= ~0x01;
1337 		bssid[0] |= 0x02;
1338 	}
1339 
1340 	sdata_info(sdata, "Creating new IBSS network, BSSID %pM\n", bssid);
1341 
1342 	capability = WLAN_CAPABILITY_IBSS;
1343 
1344 	if (ifibss->privacy)
1345 		capability |= WLAN_CAPABILITY_PRIVACY;
1346 
1347 	__ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
1348 				  &ifibss->chandef, ifibss->basic_rates,
1349 				  capability, 0, true);
1350 }
1351 
1352 static unsigned ibss_setup_channels(struct wiphy *wiphy,
1353 				    struct ieee80211_channel **channels,
1354 				    unsigned int channels_max,
1355 				    u32 center_freq, u32 width)
1356 {
1357 	struct ieee80211_channel *chan = NULL;
1358 	unsigned int n_chan = 0;
1359 	u32 start_freq, end_freq, freq;
1360 
1361 	if (width <= 20) {
1362 		start_freq = center_freq;
1363 		end_freq = center_freq;
1364 	} else {
1365 		start_freq = center_freq - width / 2 + 10;
1366 		end_freq = center_freq + width / 2 - 10;
1367 	}
1368 
1369 	for (freq = start_freq; freq <= end_freq; freq += 20) {
1370 		chan = ieee80211_get_channel(wiphy, freq);
1371 		if (!chan)
1372 			continue;
1373 		if (n_chan >= channels_max)
1374 			return n_chan;
1375 
1376 		channels[n_chan] = chan;
1377 		n_chan++;
1378 	}
1379 
1380 	return n_chan;
1381 }
1382 
1383 static unsigned int
1384 ieee80211_ibss_setup_scan_channels(struct wiphy *wiphy,
1385 				   const struct cfg80211_chan_def *chandef,
1386 				   struct ieee80211_channel **channels,
1387 				   unsigned int channels_max)
1388 {
1389 	unsigned int n_chan = 0;
1390 	u32 width, cf1, cf2 = 0;
1391 
1392 	switch (chandef->width) {
1393 	case NL80211_CHAN_WIDTH_40:
1394 		width = 40;
1395 		break;
1396 	case NL80211_CHAN_WIDTH_80P80:
1397 		cf2 = chandef->center_freq2;
1398 		fallthrough;
1399 	case NL80211_CHAN_WIDTH_80:
1400 		width = 80;
1401 		break;
1402 	case NL80211_CHAN_WIDTH_160:
1403 		width = 160;
1404 		break;
1405 	default:
1406 		width = 20;
1407 		break;
1408 	}
1409 
1410 	cf1 = chandef->center_freq1;
1411 
1412 	n_chan = ibss_setup_channels(wiphy, channels, channels_max, cf1, width);
1413 
1414 	if (cf2)
1415 		n_chan += ibss_setup_channels(wiphy, &channels[n_chan],
1416 					      channels_max - n_chan, cf2,
1417 					      width);
1418 
1419 	return n_chan;
1420 }
1421 
1422 /*
1423  * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
1424  */
1425 
1426 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
1427 {
1428 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1429 	struct ieee80211_local *local = sdata->local;
1430 	struct cfg80211_bss *cbss;
1431 	struct ieee80211_channel *chan = NULL;
1432 	const u8 *bssid = NULL;
1433 	enum nl80211_bss_scan_width scan_width;
1434 	int active_ibss;
1435 
1436 	sdata_assert_lock(sdata);
1437 
1438 	active_ibss = ieee80211_sta_active_ibss(sdata);
1439 	ibss_dbg(sdata, "sta_find_ibss (active_ibss=%d)\n", active_ibss);
1440 
1441 	if (active_ibss)
1442 		return;
1443 
1444 	if (ifibss->fixed_bssid)
1445 		bssid = ifibss->bssid;
1446 	if (ifibss->fixed_channel)
1447 		chan = ifibss->chandef.chan;
1448 	if (!is_zero_ether_addr(ifibss->bssid))
1449 		bssid = ifibss->bssid;
1450 	cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
1451 				ifibss->ssid, ifibss->ssid_len,
1452 				IEEE80211_BSS_TYPE_IBSS,
1453 				IEEE80211_PRIVACY(ifibss->privacy));
1454 
1455 	if (cbss) {
1456 		struct ieee80211_bss *bss;
1457 
1458 		bss = (void *)cbss->priv;
1459 		ibss_dbg(sdata,
1460 			 "sta_find_ibss: selected %pM current %pM\n",
1461 			 cbss->bssid, ifibss->bssid);
1462 		sdata_info(sdata,
1463 			   "Selected IBSS BSSID %pM based on configured SSID\n",
1464 			   cbss->bssid);
1465 
1466 		ieee80211_sta_join_ibss(sdata, bss);
1467 		ieee80211_rx_bss_put(local, bss);
1468 		return;
1469 	}
1470 
1471 	/* if a fixed bssid and a fixed freq have been provided create the IBSS
1472 	 * directly and do not waste time scanning
1473 	 */
1474 	if (ifibss->fixed_bssid && ifibss->fixed_channel) {
1475 		sdata_info(sdata, "Created IBSS using preconfigured BSSID %pM\n",
1476 			   bssid);
1477 		ieee80211_sta_create_ibss(sdata);
1478 		return;
1479 	}
1480 
1481 
1482 	ibss_dbg(sdata, "sta_find_ibss: did not try to join ibss\n");
1483 
1484 	/* Selected IBSS not found in current scan results - try to scan */
1485 	if (time_after(jiffies, ifibss->last_scan_completed +
1486 					IEEE80211_SCAN_INTERVAL)) {
1487 		struct ieee80211_channel *channels[8];
1488 		unsigned int num;
1489 
1490 		sdata_info(sdata, "Trigger new scan to find an IBSS to join\n");
1491 
1492 		scan_width = cfg80211_chandef_to_scan_width(&ifibss->chandef);
1493 
1494 		if (ifibss->fixed_channel) {
1495 			num = ieee80211_ibss_setup_scan_channels(local->hw.wiphy,
1496 								 &ifibss->chandef,
1497 								 channels,
1498 								 ARRAY_SIZE(channels));
1499 			ieee80211_request_ibss_scan(sdata, ifibss->ssid,
1500 						    ifibss->ssid_len, channels,
1501 						    num, scan_width);
1502 		} else {
1503 			ieee80211_request_ibss_scan(sdata, ifibss->ssid,
1504 						    ifibss->ssid_len, NULL,
1505 						    0, scan_width);
1506 		}
1507 	} else {
1508 		int interval = IEEE80211_SCAN_INTERVAL;
1509 
1510 		if (time_after(jiffies, ifibss->ibss_join_req +
1511 			       IEEE80211_IBSS_JOIN_TIMEOUT))
1512 			ieee80211_sta_create_ibss(sdata);
1513 
1514 		mod_timer(&ifibss->timer,
1515 			  round_jiffies(jiffies + interval));
1516 	}
1517 }
1518 
1519 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
1520 					struct sk_buff *req)
1521 {
1522 	struct ieee80211_mgmt *mgmt = (void *)req->data;
1523 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1524 	struct ieee80211_local *local = sdata->local;
1525 	int tx_last_beacon, len = req->len;
1526 	struct sk_buff *skb;
1527 	struct beacon_data *presp;
1528 	u8 *pos, *end;
1529 
1530 	sdata_assert_lock(sdata);
1531 
1532 	presp = rcu_dereference_protected(ifibss->presp,
1533 					  lockdep_is_held(&sdata->wdev.mtx));
1534 
1535 	if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
1536 	    len < 24 + 2 || !presp)
1537 		return;
1538 
1539 	tx_last_beacon = drv_tx_last_beacon(local);
1540 
1541 	ibss_dbg(sdata, "RX ProbeReq SA=%pM DA=%pM\n", mgmt->sa, mgmt->da);
1542 	ibss_dbg(sdata, "\tBSSID=%pM (tx_last_beacon=%d)\n",
1543 		 mgmt->bssid, tx_last_beacon);
1544 
1545 	if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da))
1546 		return;
1547 
1548 	if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) &&
1549 	    !is_broadcast_ether_addr(mgmt->bssid))
1550 		return;
1551 
1552 	end = ((u8 *) mgmt) + len;
1553 	pos = mgmt->u.probe_req.variable;
1554 	if (pos[0] != WLAN_EID_SSID ||
1555 	    pos + 2 + pos[1] > end) {
1556 		ibss_dbg(sdata, "Invalid SSID IE in ProbeReq from %pM\n",
1557 			 mgmt->sa);
1558 		return;
1559 	}
1560 	if (pos[1] != 0 &&
1561 	    (pos[1] != ifibss->ssid_len ||
1562 	     memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
1563 		/* Ignore ProbeReq for foreign SSID */
1564 		return;
1565 	}
1566 
1567 	/* Reply with ProbeResp */
1568 	skb = dev_alloc_skb(local->tx_headroom + presp->head_len);
1569 	if (!skb)
1570 		return;
1571 
1572 	skb_reserve(skb, local->tx_headroom);
1573 	skb_put_data(skb, presp->head, presp->head_len);
1574 
1575 	memcpy(((struct ieee80211_mgmt *) skb->data)->da, mgmt->sa, ETH_ALEN);
1576 	ibss_dbg(sdata, "Sending ProbeResp to %pM\n", mgmt->sa);
1577 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
1578 
1579 	/* avoid excessive retries for probe request to wildcard SSIDs */
1580 	if (pos[1] == 0)
1581 		IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_NO_ACK;
1582 
1583 	ieee80211_tx_skb(sdata, skb);
1584 }
1585 
1586 static
1587 void ieee80211_rx_mgmt_probe_beacon(struct ieee80211_sub_if_data *sdata,
1588 				    struct ieee80211_mgmt *mgmt, size_t len,
1589 				    struct ieee80211_rx_status *rx_status)
1590 {
1591 	size_t baselen;
1592 	struct ieee802_11_elems *elems;
1593 
1594 	BUILD_BUG_ON(offsetof(typeof(mgmt->u.probe_resp), variable) !=
1595 		     offsetof(typeof(mgmt->u.beacon), variable));
1596 
1597 	/*
1598 	 * either beacon or probe_resp but the variable field is at the
1599 	 * same offset
1600 	 */
1601 	baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
1602 	if (baselen > len)
1603 		return;
1604 
1605 	elems = ieee802_11_parse_elems(mgmt->u.probe_resp.variable,
1606 				       len - baselen, false,
1607 				       mgmt->bssid, NULL);
1608 
1609 	if (elems) {
1610 		ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, elems);
1611 		kfree(elems);
1612 	}
1613 }
1614 
1615 void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
1616 				   struct sk_buff *skb)
1617 {
1618 	struct ieee80211_rx_status *rx_status;
1619 	struct ieee80211_mgmt *mgmt;
1620 	u16 fc;
1621 	struct ieee802_11_elems *elems;
1622 	int ies_len;
1623 
1624 	rx_status = IEEE80211_SKB_RXCB(skb);
1625 	mgmt = (struct ieee80211_mgmt *) skb->data;
1626 	fc = le16_to_cpu(mgmt->frame_control);
1627 
1628 	sdata_lock(sdata);
1629 
1630 	if (!sdata->u.ibss.ssid_len)
1631 		goto mgmt_out; /* not ready to merge yet */
1632 
1633 	switch (fc & IEEE80211_FCTL_STYPE) {
1634 	case IEEE80211_STYPE_PROBE_REQ:
1635 		ieee80211_rx_mgmt_probe_req(sdata, skb);
1636 		break;
1637 	case IEEE80211_STYPE_PROBE_RESP:
1638 	case IEEE80211_STYPE_BEACON:
1639 		ieee80211_rx_mgmt_probe_beacon(sdata, mgmt, skb->len,
1640 					       rx_status);
1641 		break;
1642 	case IEEE80211_STYPE_AUTH:
1643 		ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
1644 		break;
1645 	case IEEE80211_STYPE_DEAUTH:
1646 		ieee80211_rx_mgmt_deauth_ibss(sdata, mgmt, skb->len);
1647 		break;
1648 	case IEEE80211_STYPE_ACTION:
1649 		switch (mgmt->u.action.category) {
1650 		case WLAN_CATEGORY_SPECTRUM_MGMT:
1651 			ies_len = skb->len -
1652 				  offsetof(struct ieee80211_mgmt,
1653 					   u.action.u.chan_switch.variable);
1654 
1655 			if (ies_len < 0)
1656 				break;
1657 
1658 			elems = ieee802_11_parse_elems(
1659 				mgmt->u.action.u.chan_switch.variable,
1660 				ies_len, true, mgmt->bssid, NULL);
1661 
1662 			if (elems && !elems->parse_error)
1663 				ieee80211_rx_mgmt_spectrum_mgmt(sdata, mgmt,
1664 								skb->len,
1665 								rx_status,
1666 								elems);
1667 			kfree(elems);
1668 			break;
1669 		}
1670 	}
1671 
1672  mgmt_out:
1673 	sdata_unlock(sdata);
1674 }
1675 
1676 void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
1677 {
1678 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1679 	struct sta_info *sta;
1680 
1681 	sdata_lock(sdata);
1682 
1683 	/*
1684 	 * Work could be scheduled after scan or similar
1685 	 * when we aren't even joined (or trying) with a
1686 	 * network.
1687 	 */
1688 	if (!ifibss->ssid_len)
1689 		goto out;
1690 
1691 	spin_lock_bh(&ifibss->incomplete_lock);
1692 	while (!list_empty(&ifibss->incomplete_stations)) {
1693 		sta = list_first_entry(&ifibss->incomplete_stations,
1694 				       struct sta_info, list);
1695 		list_del(&sta->list);
1696 		spin_unlock_bh(&ifibss->incomplete_lock);
1697 
1698 		ieee80211_ibss_finish_sta(sta);
1699 		rcu_read_unlock();
1700 		spin_lock_bh(&ifibss->incomplete_lock);
1701 	}
1702 	spin_unlock_bh(&ifibss->incomplete_lock);
1703 
1704 	switch (ifibss->state) {
1705 	case IEEE80211_IBSS_MLME_SEARCH:
1706 		ieee80211_sta_find_ibss(sdata);
1707 		break;
1708 	case IEEE80211_IBSS_MLME_JOINED:
1709 		ieee80211_sta_merge_ibss(sdata);
1710 		break;
1711 	default:
1712 		WARN_ON(1);
1713 		break;
1714 	}
1715 
1716  out:
1717 	sdata_unlock(sdata);
1718 }
1719 
1720 static void ieee80211_ibss_timer(struct timer_list *t)
1721 {
1722 	struct ieee80211_sub_if_data *sdata =
1723 		from_timer(sdata, t, u.ibss.timer);
1724 
1725 	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
1726 }
1727 
1728 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
1729 {
1730 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1731 
1732 	timer_setup(&ifibss->timer, ieee80211_ibss_timer, 0);
1733 	INIT_LIST_HEAD(&ifibss->incomplete_stations);
1734 	spin_lock_init(&ifibss->incomplete_lock);
1735 	INIT_WORK(&ifibss->csa_connection_drop_work,
1736 		  ieee80211_csa_connection_drop_work);
1737 }
1738 
1739 /* scan finished notification */
1740 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
1741 {
1742 	struct ieee80211_sub_if_data *sdata;
1743 
1744 	mutex_lock(&local->iflist_mtx);
1745 	list_for_each_entry(sdata, &local->interfaces, list) {
1746 		if (!ieee80211_sdata_running(sdata))
1747 			continue;
1748 		if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
1749 			continue;
1750 		sdata->u.ibss.last_scan_completed = jiffies;
1751 	}
1752 	mutex_unlock(&local->iflist_mtx);
1753 }
1754 
1755 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
1756 			struct cfg80211_ibss_params *params)
1757 {
1758 	u32 changed = 0;
1759 	u32 rate_flags;
1760 	struct ieee80211_supported_band *sband;
1761 	enum ieee80211_chanctx_mode chanmode;
1762 	struct ieee80211_local *local = sdata->local;
1763 	int radar_detect_width = 0;
1764 	int i;
1765 	int ret;
1766 
1767 	if (params->chandef.chan->freq_offset) {
1768 		/* this may work, but is untested */
1769 		return -EOPNOTSUPP;
1770 	}
1771 
1772 	ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
1773 					    &params->chandef,
1774 					    sdata->wdev.iftype);
1775 	if (ret < 0)
1776 		return ret;
1777 
1778 	if (ret > 0) {
1779 		if (!params->userspace_handles_dfs)
1780 			return -EINVAL;
1781 		radar_detect_width = BIT(params->chandef.width);
1782 	}
1783 
1784 	chanmode = (params->channel_fixed && !ret) ?
1785 		IEEE80211_CHANCTX_SHARED : IEEE80211_CHANCTX_EXCLUSIVE;
1786 
1787 	mutex_lock(&local->chanctx_mtx);
1788 	ret = ieee80211_check_combinations(sdata, &params->chandef, chanmode,
1789 					   radar_detect_width);
1790 	mutex_unlock(&local->chanctx_mtx);
1791 	if (ret < 0)
1792 		return ret;
1793 
1794 	if (params->bssid) {
1795 		memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
1796 		sdata->u.ibss.fixed_bssid = true;
1797 	} else
1798 		sdata->u.ibss.fixed_bssid = false;
1799 
1800 	sdata->u.ibss.privacy = params->privacy;
1801 	sdata->u.ibss.control_port = params->control_port;
1802 	sdata->u.ibss.userspace_handles_dfs = params->userspace_handles_dfs;
1803 	sdata->u.ibss.basic_rates = params->basic_rates;
1804 	sdata->u.ibss.last_scan_completed = jiffies;
1805 
1806 	/* fix basic_rates if channel does not support these rates */
1807 	rate_flags = ieee80211_chandef_rate_flags(&params->chandef);
1808 	sband = local->hw.wiphy->bands[params->chandef.chan->band];
1809 	for (i = 0; i < sband->n_bitrates; i++) {
1810 		if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
1811 			sdata->u.ibss.basic_rates &= ~BIT(i);
1812 	}
1813 	memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate,
1814 	       sizeof(params->mcast_rate));
1815 
1816 	sdata->vif.bss_conf.beacon_int = params->beacon_interval;
1817 
1818 	sdata->u.ibss.chandef = params->chandef;
1819 	sdata->u.ibss.fixed_channel = params->channel_fixed;
1820 
1821 	if (params->ie) {
1822 		sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
1823 					   GFP_KERNEL);
1824 		if (sdata->u.ibss.ie)
1825 			sdata->u.ibss.ie_len = params->ie_len;
1826 	}
1827 
1828 	sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
1829 	sdata->u.ibss.ibss_join_req = jiffies;
1830 
1831 	memcpy(sdata->u.ibss.ssid, params->ssid, params->ssid_len);
1832 	sdata->u.ibss.ssid_len = params->ssid_len;
1833 
1834 	memcpy(&sdata->u.ibss.ht_capa, &params->ht_capa,
1835 	       sizeof(sdata->u.ibss.ht_capa));
1836 	memcpy(&sdata->u.ibss.ht_capa_mask, &params->ht_capa_mask,
1837 	       sizeof(sdata->u.ibss.ht_capa_mask));
1838 
1839 	/*
1840 	 * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is
1841 	 * reserved, but an HT STA shall protect HT transmissions as though
1842 	 * the HT Protection field were set to non-HT mixed mode.
1843 	 *
1844 	 * In an IBSS, the RIFS Mode field of the HT Operation element is
1845 	 * also reserved, but an HT STA shall operate as though this field
1846 	 * were set to 1.
1847 	 */
1848 
1849 	sdata->vif.bss_conf.ht_operation_mode |=
1850 		  IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED
1851 		| IEEE80211_HT_PARAM_RIFS_MODE;
1852 
1853 	changed |= BSS_CHANGED_HT | BSS_CHANGED_MCAST_RATE;
1854 	ieee80211_bss_info_change_notify(sdata, changed);
1855 
1856 	sdata->smps_mode = IEEE80211_SMPS_OFF;
1857 	sdata->needed_rx_chains = local->rx_chains;
1858 	sdata->control_port_over_nl80211 = params->control_port_over_nl80211;
1859 
1860 	ieee80211_queue_work(&local->hw, &sdata->work);
1861 
1862 	return 0;
1863 }
1864 
1865 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
1866 {
1867 	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1868 
1869 	ieee80211_ibss_disconnect(sdata);
1870 	ifibss->ssid_len = 0;
1871 	eth_zero_addr(ifibss->bssid);
1872 
1873 	/* remove beacon */
1874 	kfree(sdata->u.ibss.ie);
1875 	sdata->u.ibss.ie = NULL;
1876 	sdata->u.ibss.ie_len = 0;
1877 
1878 	/* on the next join, re-program HT parameters */
1879 	memset(&ifibss->ht_capa, 0, sizeof(ifibss->ht_capa));
1880 	memset(&ifibss->ht_capa_mask, 0, sizeof(ifibss->ht_capa_mask));
1881 
1882 	synchronize_rcu();
1883 
1884 	skb_queue_purge(&sdata->skb_queue);
1885 
1886 	del_timer_sync(&sdata->u.ibss.timer);
1887 
1888 	return 0;
1889 }
1890