1/*
2 * IBSS mode implementation
3 * Copyright 2003-2008, Jouni Malinen <j@w1.fi>
4 * Copyright 2004, Instant802 Networks, Inc.
5 * Copyright 2005, Devicescape Software, Inc.
6 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
7 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
8 * Copyright 2009, Johannes Berg <johannes@sipsolutions.net>
9 * Copyright 2013-2014  Intel Mobile Communications GmbH
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 */
15
16#include <linux/delay.h>
17#include <linux/slab.h>
18#include <linux/if_ether.h>
19#include <linux/skbuff.h>
20#include <linux/if_arp.h>
21#include <linux/etherdevice.h>
22#include <linux/rtnetlink.h>
23#include <net/mac80211.h>
24
25#include "ieee80211_i.h"
26#include "driver-ops.h"
27#include "rate.h"
28
29#define IEEE80211_SCAN_INTERVAL (2 * HZ)
30#define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)
31
32#define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
33#define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)
34#define IEEE80211_IBSS_RSN_INACTIVITY_LIMIT (10 * HZ)
35
36#define IEEE80211_IBSS_MAX_STA_ENTRIES 128
37
38static struct beacon_data *
39ieee80211_ibss_build_presp(struct ieee80211_sub_if_data *sdata,
40			   const int beacon_int, const u32 basic_rates,
41			   const u16 capability, u64 tsf,
42			   struct cfg80211_chan_def *chandef,
43			   bool *have_higher_than_11mbit,
44			   struct cfg80211_csa_settings *csa_settings)
45{
46	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
47	struct ieee80211_local *local = sdata->local;
48	int rates_n = 0, i, ri;
49	struct ieee80211_mgmt *mgmt;
50	u8 *pos;
51	struct ieee80211_supported_band *sband;
52	u32 rate_flags, rates = 0, rates_added = 0;
53	struct beacon_data *presp;
54	int frame_len;
55	int shift;
56
57	/* Build IBSS probe response */
58	frame_len = sizeof(struct ieee80211_hdr_3addr) +
59		    12 /* struct ieee80211_mgmt.u.beacon */ +
60		    2 + IEEE80211_MAX_SSID_LEN /* max SSID */ +
61		    2 + 8 /* max Supported Rates */ +
62		    3 /* max DS params */ +
63		    4 /* IBSS params */ +
64		    5 /* Channel Switch Announcement */ +
65		    2 + (IEEE80211_MAX_SUPP_RATES - 8) +
66		    2 + sizeof(struct ieee80211_ht_cap) +
67		    2 + sizeof(struct ieee80211_ht_operation) +
68		    ifibss->ie_len;
69	presp = kzalloc(sizeof(*presp) + frame_len, GFP_KERNEL);
70	if (!presp)
71		return NULL;
72
73	presp->head = (void *)(presp + 1);
74
75	mgmt = (void *) presp->head;
76	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
77					  IEEE80211_STYPE_PROBE_RESP);
78	eth_broadcast_addr(mgmt->da);
79	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
80	memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
81	mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
82	mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
83	mgmt->u.beacon.capab_info = cpu_to_le16(capability);
84
85	pos = (u8 *)mgmt + offsetof(struct ieee80211_mgmt, u.beacon.variable);
86
87	*pos++ = WLAN_EID_SSID;
88	*pos++ = ifibss->ssid_len;
89	memcpy(pos, ifibss->ssid, ifibss->ssid_len);
90	pos += ifibss->ssid_len;
91
92	sband = local->hw.wiphy->bands[chandef->chan->band];
93	rate_flags = ieee80211_chandef_rate_flags(chandef);
94	shift = ieee80211_chandef_get_shift(chandef);
95	rates_n = 0;
96	if (have_higher_than_11mbit)
97		*have_higher_than_11mbit = false;
98
99	for (i = 0; i < sband->n_bitrates; i++) {
100		if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
101			continue;
102		if (sband->bitrates[i].bitrate > 110 &&
103		    have_higher_than_11mbit)
104			*have_higher_than_11mbit = true;
105
106		rates |= BIT(i);
107		rates_n++;
108	}
109
110	*pos++ = WLAN_EID_SUPP_RATES;
111	*pos++ = min_t(int, 8, rates_n);
112	for (ri = 0; ri < sband->n_bitrates; ri++) {
113		int rate = DIV_ROUND_UP(sband->bitrates[ri].bitrate,
114					5 * (1 << shift));
115		u8 basic = 0;
116		if (!(rates & BIT(ri)))
117			continue;
118
119		if (basic_rates & BIT(ri))
120			basic = 0x80;
121		*pos++ = basic | (u8) rate;
122		if (++rates_added == 8) {
123			ri++; /* continue at next rate for EXT_SUPP_RATES */
124			break;
125		}
126	}
127
128	if (sband->band == IEEE80211_BAND_2GHZ) {
129		*pos++ = WLAN_EID_DS_PARAMS;
130		*pos++ = 1;
131		*pos++ = ieee80211_frequency_to_channel(
132				chandef->chan->center_freq);
133	}
134
135	*pos++ = WLAN_EID_IBSS_PARAMS;
136	*pos++ = 2;
137	/* FIX: set ATIM window based on scan results */
138	*pos++ = 0;
139	*pos++ = 0;
140
141	if (csa_settings) {
142		*pos++ = WLAN_EID_CHANNEL_SWITCH;
143		*pos++ = 3;
144		*pos++ = csa_settings->block_tx ? 1 : 0;
145		*pos++ = ieee80211_frequency_to_channel(
146				csa_settings->chandef.chan->center_freq);
147		presp->csa_counter_offsets[0] = (pos - presp->head);
148		*pos++ = csa_settings->count;
149	}
150
151	/* put the remaining rates in WLAN_EID_EXT_SUPP_RATES */
152	if (rates_n > 8) {
153		*pos++ = WLAN_EID_EXT_SUPP_RATES;
154		*pos++ = rates_n - 8;
155		for (; ri < sband->n_bitrates; ri++) {
156			int rate = DIV_ROUND_UP(sband->bitrates[ri].bitrate,
157						5 * (1 << shift));
158			u8 basic = 0;
159			if (!(rates & BIT(ri)))
160				continue;
161
162			if (basic_rates & BIT(ri))
163				basic = 0x80;
164			*pos++ = basic | (u8) rate;
165		}
166	}
167
168	if (ifibss->ie_len) {
169		memcpy(pos, ifibss->ie, ifibss->ie_len);
170		pos += ifibss->ie_len;
171	}
172
173	/* add HT capability and information IEs */
174	if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT &&
175	    chandef->width != NL80211_CHAN_WIDTH_5 &&
176	    chandef->width != NL80211_CHAN_WIDTH_10 &&
177	    sband->ht_cap.ht_supported) {
178		struct ieee80211_sta_ht_cap ht_cap;
179
180		memcpy(&ht_cap, &sband->ht_cap, sizeof(ht_cap));
181		ieee80211_apply_htcap_overrides(sdata, &ht_cap);
182
183		pos = ieee80211_ie_build_ht_cap(pos, &ht_cap, ht_cap.cap);
184		/*
185		 * Note: According to 802.11n-2009 9.13.3.1, HT Protection
186		 * field and RIFS Mode are reserved in IBSS mode, therefore
187		 * keep them at 0
188		 */
189		pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap,
190						 chandef, 0);
191	}
192
193	if (local->hw.queues >= IEEE80211_NUM_ACS)
194		pos = ieee80211_add_wmm_info_ie(pos, 0); /* U-APSD not in use */
195
196	presp->head_len = pos - presp->head;
197	if (WARN_ON(presp->head_len > frame_len))
198		goto error;
199
200	return presp;
201error:
202	kfree(presp);
203	return NULL;
204}
205
206static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
207				      const u8 *bssid, const int beacon_int,
208				      struct cfg80211_chan_def *req_chandef,
209				      const u32 basic_rates,
210				      const u16 capability, u64 tsf,
211				      bool creator)
212{
213	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
214	struct ieee80211_local *local = sdata->local;
215	struct ieee80211_mgmt *mgmt;
216	struct cfg80211_bss *bss;
217	u32 bss_change;
218	struct cfg80211_chan_def chandef;
219	struct ieee80211_channel *chan;
220	struct beacon_data *presp;
221	enum nl80211_bss_scan_width scan_width;
222	bool have_higher_than_11mbit;
223	bool radar_required;
224	int err;
225
226	sdata_assert_lock(sdata);
227
228	/* Reset own TSF to allow time synchronization work. */
229	drv_reset_tsf(local, sdata);
230
231	if (!ether_addr_equal(ifibss->bssid, bssid))
232		sta_info_flush(sdata);
233
234	/* if merging, indicate to driver that we leave the old IBSS */
235	if (sdata->vif.bss_conf.ibss_joined) {
236		sdata->vif.bss_conf.ibss_joined = false;
237		sdata->vif.bss_conf.ibss_creator = false;
238		sdata->vif.bss_conf.enable_beacon = false;
239		netif_carrier_off(sdata->dev);
240		ieee80211_bss_info_change_notify(sdata,
241						 BSS_CHANGED_IBSS |
242						 BSS_CHANGED_BEACON_ENABLED);
243		drv_leave_ibss(local, sdata);
244	}
245
246	presp = rcu_dereference_protected(ifibss->presp,
247					  lockdep_is_held(&sdata->wdev.mtx));
248	RCU_INIT_POINTER(ifibss->presp, NULL);
249	if (presp)
250		kfree_rcu(presp, rcu_head);
251
252	sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
253
254	/* make a copy of the chandef, it could be modified below. */
255	chandef = *req_chandef;
256	chan = chandef.chan;
257	if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef,
258				     NL80211_IFTYPE_ADHOC)) {
259		if (chandef.width == NL80211_CHAN_WIDTH_5 ||
260		    chandef.width == NL80211_CHAN_WIDTH_10 ||
261		    chandef.width == NL80211_CHAN_WIDTH_20_NOHT ||
262		    chandef.width == NL80211_CHAN_WIDTH_20) {
263			sdata_info(sdata,
264				   "Failed to join IBSS, beacons forbidden\n");
265			return;
266		}
267		chandef.width = NL80211_CHAN_WIDTH_20;
268		chandef.center_freq1 = chan->center_freq;
269		/* check again for downgraded chandef */
270		if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef,
271					     NL80211_IFTYPE_ADHOC)) {
272			sdata_info(sdata,
273				   "Failed to join IBSS, beacons forbidden\n");
274			return;
275		}
276	}
277
278	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
279					    &chandef, NL80211_IFTYPE_ADHOC);
280	if (err < 0) {
281		sdata_info(sdata,
282			   "Failed to join IBSS, invalid chandef\n");
283		return;
284	}
285	if (err > 0 && !ifibss->userspace_handles_dfs) {
286		sdata_info(sdata,
287			   "Failed to join IBSS, DFS channel without control program\n");
288		return;
289	}
290
291	radar_required = err;
292
293	mutex_lock(&local->mtx);
294	if (ieee80211_vif_use_channel(sdata, &chandef,
295				      ifibss->fixed_channel ?
296					IEEE80211_CHANCTX_SHARED :
297					IEEE80211_CHANCTX_EXCLUSIVE)) {
298		sdata_info(sdata, "Failed to join IBSS, no channel context\n");
299		mutex_unlock(&local->mtx);
300		return;
301	}
302	sdata->radar_required = radar_required;
303	mutex_unlock(&local->mtx);
304
305	memcpy(ifibss->bssid, bssid, ETH_ALEN);
306
307	presp = ieee80211_ibss_build_presp(sdata, beacon_int, basic_rates,
308					   capability, tsf, &chandef,
309					   &have_higher_than_11mbit, NULL);
310	if (!presp)
311		return;
312
313	rcu_assign_pointer(ifibss->presp, presp);
314	mgmt = (void *)presp->head;
315
316	sdata->vif.bss_conf.enable_beacon = true;
317	sdata->vif.bss_conf.beacon_int = beacon_int;
318	sdata->vif.bss_conf.basic_rates = basic_rates;
319	sdata->vif.bss_conf.ssid_len = ifibss->ssid_len;
320	memcpy(sdata->vif.bss_conf.ssid, ifibss->ssid, ifibss->ssid_len);
321	bss_change = BSS_CHANGED_BEACON_INT;
322	bss_change |= ieee80211_reset_erp_info(sdata);
323	bss_change |= BSS_CHANGED_BSSID;
324	bss_change |= BSS_CHANGED_BEACON;
325	bss_change |= BSS_CHANGED_BEACON_ENABLED;
326	bss_change |= BSS_CHANGED_BASIC_RATES;
327	bss_change |= BSS_CHANGED_HT;
328	bss_change |= BSS_CHANGED_IBSS;
329	bss_change |= BSS_CHANGED_SSID;
330
331	/*
332	 * In 5 GHz/802.11a, we can always use short slot time.
333	 * (IEEE 802.11-2012 18.3.8.7)
334	 *
335	 * In 2.4GHz, we must always use long slots in IBSS for compatibility
336	 * reasons.
337	 * (IEEE 802.11-2012 19.4.5)
338	 *
339	 * HT follows these specifications (IEEE 802.11-2012 20.3.18)
340	 */
341	sdata->vif.bss_conf.use_short_slot = chan->band == IEEE80211_BAND_5GHZ;
342	bss_change |= BSS_CHANGED_ERP_SLOT;
343
344	/* cf. IEEE 802.11 9.2.12 */
345	if (chan->band == IEEE80211_BAND_2GHZ && have_higher_than_11mbit)
346		sdata->flags |= IEEE80211_SDATA_OPERATING_GMODE;
347	else
348		sdata->flags &= ~IEEE80211_SDATA_OPERATING_GMODE;
349
350	ieee80211_set_wmm_default(sdata, true);
351
352	sdata->vif.bss_conf.ibss_joined = true;
353	sdata->vif.bss_conf.ibss_creator = creator;
354
355	err = drv_join_ibss(local, sdata);
356	if (err) {
357		sdata->vif.bss_conf.ibss_joined = false;
358		sdata->vif.bss_conf.ibss_creator = false;
359		sdata->vif.bss_conf.enable_beacon = false;
360		sdata->vif.bss_conf.ssid_len = 0;
361		RCU_INIT_POINTER(ifibss->presp, NULL);
362		kfree_rcu(presp, rcu_head);
363		mutex_lock(&local->mtx);
364		ieee80211_vif_release_channel(sdata);
365		mutex_unlock(&local->mtx);
366		sdata_info(sdata, "Failed to join IBSS, driver failure: %d\n",
367			   err);
368		return;
369	}
370
371	ieee80211_bss_info_change_notify(sdata, bss_change);
372
373	ifibss->state = IEEE80211_IBSS_MLME_JOINED;
374	mod_timer(&ifibss->timer,
375		  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
376
377	scan_width = cfg80211_chandef_to_scan_width(&chandef);
378	bss = cfg80211_inform_bss_width_frame(local->hw.wiphy, chan,
379					      scan_width, mgmt,
380					      presp->head_len, 0, GFP_KERNEL);
381	cfg80211_put_bss(local->hw.wiphy, bss);
382	netif_carrier_on(sdata->dev);
383	cfg80211_ibss_joined(sdata->dev, ifibss->bssid, chan, GFP_KERNEL);
384}
385
386static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
387				    struct ieee80211_bss *bss)
388{
389	struct cfg80211_bss *cbss =
390		container_of((void *)bss, struct cfg80211_bss, priv);
391	struct ieee80211_supported_band *sband;
392	struct cfg80211_chan_def chandef;
393	u32 basic_rates;
394	int i, j;
395	u16 beacon_int = cbss->beacon_interval;
396	const struct cfg80211_bss_ies *ies;
397	enum nl80211_channel_type chan_type;
398	u64 tsf;
399	u32 rate_flags;
400	int shift;
401
402	sdata_assert_lock(sdata);
403
404	if (beacon_int < 10)
405		beacon_int = 10;
406
407	switch (sdata->u.ibss.chandef.width) {
408	case NL80211_CHAN_WIDTH_20_NOHT:
409	case NL80211_CHAN_WIDTH_20:
410	case NL80211_CHAN_WIDTH_40:
411		chan_type = cfg80211_get_chandef_type(&sdata->u.ibss.chandef);
412		cfg80211_chandef_create(&chandef, cbss->channel, chan_type);
413		break;
414	case NL80211_CHAN_WIDTH_5:
415	case NL80211_CHAN_WIDTH_10:
416		cfg80211_chandef_create(&chandef, cbss->channel,
417					NL80211_CHAN_WIDTH_20_NOHT);
418		chandef.width = sdata->u.ibss.chandef.width;
419		break;
420	default:
421		/* fall back to 20 MHz for unsupported modes */
422		cfg80211_chandef_create(&chandef, cbss->channel,
423					NL80211_CHAN_WIDTH_20_NOHT);
424		break;
425	}
426
427	sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
428	rate_flags = ieee80211_chandef_rate_flags(&sdata->u.ibss.chandef);
429	shift = ieee80211_vif_get_shift(&sdata->vif);
430
431	basic_rates = 0;
432
433	for (i = 0; i < bss->supp_rates_len; i++) {
434		int rate = bss->supp_rates[i] & 0x7f;
435		bool is_basic = !!(bss->supp_rates[i] & 0x80);
436
437		for (j = 0; j < sband->n_bitrates; j++) {
438			int brate;
439			if ((rate_flags & sband->bitrates[j].flags)
440			    != rate_flags)
441				continue;
442
443			brate = DIV_ROUND_UP(sband->bitrates[j].bitrate,
444					     5 * (1 << shift));
445			if (brate == rate) {
446				if (is_basic)
447					basic_rates |= BIT(j);
448				break;
449			}
450		}
451	}
452
453	rcu_read_lock();
454	ies = rcu_dereference(cbss->ies);
455	tsf = ies->tsf;
456	rcu_read_unlock();
457
458	__ieee80211_sta_join_ibss(sdata, cbss->bssid,
459				  beacon_int,
460				  &chandef,
461				  basic_rates,
462				  cbss->capability,
463				  tsf, false);
464}
465
466int ieee80211_ibss_csa_beacon(struct ieee80211_sub_if_data *sdata,
467			      struct cfg80211_csa_settings *csa_settings)
468{
469	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
470	struct beacon_data *presp, *old_presp;
471	struct cfg80211_bss *cbss;
472	const struct cfg80211_bss_ies *ies;
473	u16 capability;
474	u64 tsf;
475	int ret = 0;
476
477	sdata_assert_lock(sdata);
478
479	capability = WLAN_CAPABILITY_IBSS;
480
481	if (ifibss->privacy)
482		capability |= WLAN_CAPABILITY_PRIVACY;
483
484	cbss = cfg80211_get_bss(sdata->local->hw.wiphy, ifibss->chandef.chan,
485				ifibss->bssid, ifibss->ssid,
486				ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
487				WLAN_CAPABILITY_PRIVACY,
488				capability);
489
490	if (WARN_ON(!cbss)) {
491		ret = -EINVAL;
492		goto out;
493	}
494
495	rcu_read_lock();
496	ies = rcu_dereference(cbss->ies);
497	tsf = ies->tsf;
498	rcu_read_unlock();
499	cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
500
501	old_presp = rcu_dereference_protected(ifibss->presp,
502					  lockdep_is_held(&sdata->wdev.mtx));
503
504	presp = ieee80211_ibss_build_presp(sdata,
505					   sdata->vif.bss_conf.beacon_int,
506					   sdata->vif.bss_conf.basic_rates,
507					   capability, tsf, &ifibss->chandef,
508					   NULL, csa_settings);
509	if (!presp) {
510		ret = -ENOMEM;
511		goto out;
512	}
513
514	rcu_assign_pointer(ifibss->presp, presp);
515	if (old_presp)
516		kfree_rcu(old_presp, rcu_head);
517
518	return BSS_CHANGED_BEACON;
519 out:
520	return ret;
521}
522
523int ieee80211_ibss_finish_csa(struct ieee80211_sub_if_data *sdata)
524{
525	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
526	struct cfg80211_bss *cbss;
527	int err, changed = 0;
528	u16 capability;
529
530	sdata_assert_lock(sdata);
531
532	/* update cfg80211 bss information with the new channel */
533	if (!is_zero_ether_addr(ifibss->bssid)) {
534		capability = WLAN_CAPABILITY_IBSS;
535
536		if (ifibss->privacy)
537			capability |= WLAN_CAPABILITY_PRIVACY;
538
539		cbss = cfg80211_get_bss(sdata->local->hw.wiphy,
540					ifibss->chandef.chan,
541					ifibss->bssid, ifibss->ssid,
542					ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
543					WLAN_CAPABILITY_PRIVACY,
544					capability);
545		/* XXX: should not really modify cfg80211 data */
546		if (cbss) {
547			cbss->channel = sdata->csa_chandef.chan;
548			cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
549		}
550	}
551
552	ifibss->chandef = sdata->csa_chandef;
553
554	/* generate the beacon */
555	err = ieee80211_ibss_csa_beacon(sdata, NULL);
556	if (err < 0)
557		return err;
558
559	changed |= err;
560
561	return changed;
562}
563
564void ieee80211_ibss_stop(struct ieee80211_sub_if_data *sdata)
565{
566	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
567
568	cancel_work_sync(&ifibss->csa_connection_drop_work);
569}
570
571static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta)
572	__acquires(RCU)
573{
574	struct ieee80211_sub_if_data *sdata = sta->sdata;
575	u8 addr[ETH_ALEN];
576
577	memcpy(addr, sta->sta.addr, ETH_ALEN);
578
579	ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr);
580
581	sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
582	sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
583	/* authorize the station only if the network is not RSN protected. If
584	 * not wait for the userspace to authorize it */
585	if (!sta->sdata->u.ibss.control_port)
586		sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
587
588	rate_control_rate_init(sta);
589
590	/* If it fails, maybe we raced another insertion? */
591	if (sta_info_insert_rcu(sta))
592		return sta_info_get(sdata, addr);
593	return sta;
594}
595
596static struct sta_info *
597ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, const u8 *bssid,
598		       const u8 *addr, u32 supp_rates)
599	__acquires(RCU)
600{
601	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
602	struct ieee80211_local *local = sdata->local;
603	struct sta_info *sta;
604	struct ieee80211_chanctx_conf *chanctx_conf;
605	struct ieee80211_supported_band *sband;
606	enum nl80211_bss_scan_width scan_width;
607	int band;
608
609	/*
610	 * XXX: Consider removing the least recently used entry and
611	 * 	allow new one to be added.
612	 */
613	if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
614		net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
615				    sdata->name, addr);
616		rcu_read_lock();
617		return NULL;
618	}
619
620	if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) {
621		rcu_read_lock();
622		return NULL;
623	}
624
625	if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) {
626		rcu_read_lock();
627		return NULL;
628	}
629
630	rcu_read_lock();
631	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
632	if (WARN_ON_ONCE(!chanctx_conf))
633		return NULL;
634	band = chanctx_conf->def.chan->band;
635	scan_width = cfg80211_chandef_to_scan_width(&chanctx_conf->def);
636	rcu_read_unlock();
637
638	sta = sta_info_alloc(sdata, addr, GFP_KERNEL);
639	if (!sta) {
640		rcu_read_lock();
641		return NULL;
642	}
643
644	sta->last_rx = jiffies;
645
646	/* make sure mandatory rates are always added */
647	sband = local->hw.wiphy->bands[band];
648	sta->sta.supp_rates[band] = supp_rates |
649			ieee80211_mandatory_rates(sband, scan_width);
650
651	return ieee80211_ibss_finish_sta(sta);
652}
653
654static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
655{
656	struct ieee80211_local *local = sdata->local;
657	int active = 0;
658	struct sta_info *sta;
659
660	sdata_assert_lock(sdata);
661
662	rcu_read_lock();
663
664	list_for_each_entry_rcu(sta, &local->sta_list, list) {
665		if (sta->sdata == sdata &&
666		    time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
667			       jiffies)) {
668			active++;
669			break;
670		}
671	}
672
673	rcu_read_unlock();
674
675	return active;
676}
677
678static void ieee80211_ibss_disconnect(struct ieee80211_sub_if_data *sdata)
679{
680	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
681	struct ieee80211_local *local = sdata->local;
682	struct cfg80211_bss *cbss;
683	struct beacon_data *presp;
684	struct sta_info *sta;
685	u16 capability;
686
687	if (!is_zero_ether_addr(ifibss->bssid)) {
688		capability = WLAN_CAPABILITY_IBSS;
689
690		if (ifibss->privacy)
691			capability |= WLAN_CAPABILITY_PRIVACY;
692
693		cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->chandef.chan,
694					ifibss->bssid, ifibss->ssid,
695					ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
696					WLAN_CAPABILITY_PRIVACY,
697					capability);
698
699		if (cbss) {
700			cfg80211_unlink_bss(local->hw.wiphy, cbss);
701			cfg80211_put_bss(sdata->local->hw.wiphy, cbss);
702		}
703	}
704
705	ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
706
707	sta_info_flush(sdata);
708
709	spin_lock_bh(&ifibss->incomplete_lock);
710	while (!list_empty(&ifibss->incomplete_stations)) {
711		sta = list_first_entry(&ifibss->incomplete_stations,
712				       struct sta_info, list);
713		list_del(&sta->list);
714		spin_unlock_bh(&ifibss->incomplete_lock);
715
716		sta_info_free(local, sta);
717		spin_lock_bh(&ifibss->incomplete_lock);
718	}
719	spin_unlock_bh(&ifibss->incomplete_lock);
720
721	netif_carrier_off(sdata->dev);
722
723	sdata->vif.bss_conf.ibss_joined = false;
724	sdata->vif.bss_conf.ibss_creator = false;
725	sdata->vif.bss_conf.enable_beacon = false;
726	sdata->vif.bss_conf.ssid_len = 0;
727
728	/* remove beacon */
729	presp = rcu_dereference_protected(ifibss->presp,
730					  lockdep_is_held(&sdata->wdev.mtx));
731	RCU_INIT_POINTER(sdata->u.ibss.presp, NULL);
732	if (presp)
733		kfree_rcu(presp, rcu_head);
734
735	clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED, &sdata->state);
736	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
737						BSS_CHANGED_IBSS);
738	drv_leave_ibss(local, sdata);
739	mutex_lock(&local->mtx);
740	ieee80211_vif_release_channel(sdata);
741	mutex_unlock(&local->mtx);
742}
743
744static void ieee80211_csa_connection_drop_work(struct work_struct *work)
745{
746	struct ieee80211_sub_if_data *sdata =
747		container_of(work, struct ieee80211_sub_if_data,
748			     u.ibss.csa_connection_drop_work);
749
750	sdata_lock(sdata);
751
752	ieee80211_ibss_disconnect(sdata);
753	synchronize_rcu();
754	skb_queue_purge(&sdata->skb_queue);
755
756	/* trigger a scan to find another IBSS network to join */
757	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
758
759	sdata_unlock(sdata);
760}
761
762static void ieee80211_ibss_csa_mark_radar(struct ieee80211_sub_if_data *sdata)
763{
764	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
765	int err;
766
767	/* if the current channel is a DFS channel, mark the channel as
768	 * unavailable.
769	 */
770	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
771					    &ifibss->chandef,
772					    NL80211_IFTYPE_ADHOC);
773	if (err > 0)
774		cfg80211_radar_event(sdata->local->hw.wiphy, &ifibss->chandef,
775				     GFP_ATOMIC);
776}
777
778static bool
779ieee80211_ibss_process_chanswitch(struct ieee80211_sub_if_data *sdata,
780				  struct ieee802_11_elems *elems,
781				  bool beacon)
782{
783	struct cfg80211_csa_settings params;
784	struct ieee80211_csa_ie csa_ie;
785	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
786	enum nl80211_channel_type ch_type;
787	int err;
788	u32 sta_flags;
789
790	sdata_assert_lock(sdata);
791
792	sta_flags = IEEE80211_STA_DISABLE_VHT;
793	switch (ifibss->chandef.width) {
794	case NL80211_CHAN_WIDTH_5:
795	case NL80211_CHAN_WIDTH_10:
796	case NL80211_CHAN_WIDTH_20_NOHT:
797		sta_flags |= IEEE80211_STA_DISABLE_HT;
798		/* fall through */
799	case NL80211_CHAN_WIDTH_20:
800		sta_flags |= IEEE80211_STA_DISABLE_40MHZ;
801		break;
802	default:
803		break;
804	}
805
806	memset(&params, 0, sizeof(params));
807	memset(&csa_ie, 0, sizeof(csa_ie));
808	err = ieee80211_parse_ch_switch_ie(sdata, elems,
809					   ifibss->chandef.chan->band,
810					   sta_flags, ifibss->bssid, &csa_ie);
811	/* can't switch to destination channel, fail */
812	if (err < 0)
813		goto disconnect;
814
815	/* did not contain a CSA */
816	if (err)
817		return false;
818
819	/* channel switch is not supported, disconnect */
820	if (!(sdata->local->hw.wiphy->flags & WIPHY_FLAG_HAS_CHANNEL_SWITCH))
821		goto disconnect;
822
823	params.count = csa_ie.count;
824	params.chandef = csa_ie.chandef;
825
826	switch (ifibss->chandef.width) {
827	case NL80211_CHAN_WIDTH_20_NOHT:
828	case NL80211_CHAN_WIDTH_20:
829	case NL80211_CHAN_WIDTH_40:
830		/* keep our current HT mode (HT20/HT40+/HT40-), even if
831		 * another mode  has been announced. The mode is not adopted
832		 * within the beacon while doing CSA and we should therefore
833		 * keep the mode which we announce.
834		 */
835		ch_type = cfg80211_get_chandef_type(&ifibss->chandef);
836		cfg80211_chandef_create(&params.chandef, params.chandef.chan,
837					ch_type);
838		break;
839	case NL80211_CHAN_WIDTH_5:
840	case NL80211_CHAN_WIDTH_10:
841		if (params.chandef.width != ifibss->chandef.width) {
842			sdata_info(sdata,
843				   "IBSS %pM received channel switch from incompatible channel width (%d MHz, width:%d, CF1/2: %d/%d MHz), disconnecting\n",
844				   ifibss->bssid,
845				   params.chandef.chan->center_freq,
846				   params.chandef.width,
847				   params.chandef.center_freq1,
848				   params.chandef.center_freq2);
849			goto disconnect;
850		}
851		break;
852	default:
853		/* should not happen, sta_flags should prevent VHT modes. */
854		WARN_ON(1);
855		goto disconnect;
856	}
857
858	if (!cfg80211_reg_can_beacon(sdata->local->hw.wiphy, &params.chandef,
859				     NL80211_IFTYPE_ADHOC)) {
860		sdata_info(sdata,
861			   "IBSS %pM switches to unsupported channel (%d MHz, width:%d, CF1/2: %d/%d MHz), disconnecting\n",
862			   ifibss->bssid,
863			   params.chandef.chan->center_freq,
864			   params.chandef.width,
865			   params.chandef.center_freq1,
866			   params.chandef.center_freq2);
867		goto disconnect;
868	}
869
870	err = cfg80211_chandef_dfs_required(sdata->local->hw.wiphy,
871					    &params.chandef,
872					    NL80211_IFTYPE_ADHOC);
873	if (err < 0)
874		goto disconnect;
875	if (err > 0 && !ifibss->userspace_handles_dfs) {
876		/* IBSS-DFS only allowed with a control program */
877		goto disconnect;
878	}
879
880	params.radar_required = err;
881
882	if (cfg80211_chandef_identical(&params.chandef,
883				       &sdata->vif.bss_conf.chandef)) {
884		ibss_dbg(sdata,
885			 "received csa with an identical chandef, ignoring\n");
886		return true;
887	}
888
889	/* all checks done, now perform the channel switch. */
890	ibss_dbg(sdata,
891		 "received channel switch announcement to go to channel %d MHz\n",
892		 params.chandef.chan->center_freq);
893
894	params.block_tx = !!csa_ie.mode;
895
896	if (ieee80211_channel_switch(sdata->local->hw.wiphy, sdata->dev,
897				     &params))
898		goto disconnect;
899
900	ieee80211_ibss_csa_mark_radar(sdata);
901
902	return true;
903disconnect:
904	ibss_dbg(sdata, "Can't handle channel switch, disconnect\n");
905	ieee80211_queue_work(&sdata->local->hw,
906			     &ifibss->csa_connection_drop_work);
907
908	ieee80211_ibss_csa_mark_radar(sdata);
909
910	return true;
911}
912
913static void
914ieee80211_rx_mgmt_spectrum_mgmt(struct ieee80211_sub_if_data *sdata,
915				struct ieee80211_mgmt *mgmt, size_t len,
916				struct ieee80211_rx_status *rx_status,
917				struct ieee802_11_elems *elems)
918{
919	int required_len;
920
921	if (len < IEEE80211_MIN_ACTION_SIZE + 1)
922		return;
923
924	/* CSA is the only action we handle for now */
925	if (mgmt->u.action.u.measurement.action_code !=
926	    WLAN_ACTION_SPCT_CHL_SWITCH)
927		return;
928
929	required_len = IEEE80211_MIN_ACTION_SIZE +
930		       sizeof(mgmt->u.action.u.chan_switch);
931	if (len < required_len)
932		return;
933
934	if (!sdata->vif.csa_active)
935		ieee80211_ibss_process_chanswitch(sdata, elems, false);
936}
937
938static void ieee80211_rx_mgmt_deauth_ibss(struct ieee80211_sub_if_data *sdata,
939					  struct ieee80211_mgmt *mgmt,
940					  size_t len)
941{
942	u16 reason = le16_to_cpu(mgmt->u.deauth.reason_code);
943
944	if (len < IEEE80211_DEAUTH_FRAME_LEN)
945		return;
946
947	ibss_dbg(sdata, "RX DeAuth SA=%pM DA=%pM BSSID=%pM (reason: %d)\n",
948		 mgmt->sa, mgmt->da, mgmt->bssid, reason);
949	sta_info_destroy_addr(sdata, mgmt->sa);
950}
951
952static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
953					struct ieee80211_mgmt *mgmt,
954					size_t len)
955{
956	u16 auth_alg, auth_transaction;
957
958	sdata_assert_lock(sdata);
959
960	if (len < 24 + 6)
961		return;
962
963	auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
964	auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
965
966	ibss_dbg(sdata,
967		 "RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n",
968		 mgmt->sa, mgmt->da, mgmt->bssid, auth_transaction);
969
970	if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1)
971		return;
972
973	/*
974	 * IEEE 802.11 standard does not require authentication in IBSS
975	 * networks and most implementations do not seem to use it.
976	 * However, try to reply to authentication attempts if someone
977	 * has actually implemented this.
978	 */
979	ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, 0, NULL, 0,
980			    mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0, 0);
981}
982
983static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
984				  struct ieee80211_mgmt *mgmt, size_t len,
985				  struct ieee80211_rx_status *rx_status,
986				  struct ieee802_11_elems *elems)
987{
988	struct ieee80211_local *local = sdata->local;
989	struct cfg80211_bss *cbss;
990	struct ieee80211_bss *bss;
991	struct sta_info *sta;
992	struct ieee80211_channel *channel;
993	u64 beacon_timestamp, rx_timestamp;
994	u32 supp_rates = 0;
995	enum ieee80211_band band = rx_status->band;
996	enum nl80211_bss_scan_width scan_width;
997	struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
998	bool rates_updated = false;
999
1000	channel = ieee80211_get_channel(local->hw.wiphy, rx_status->freq);
1001	if (!channel)
1002		return;
1003
1004	if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
1005	    ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid)) {
1006
1007		rcu_read_lock();
1008		sta = sta_info_get(sdata, mgmt->sa);
1009
1010		if (elems->supp_rates) {
1011			supp_rates = ieee80211_sta_get_rates(sdata, elems,
1012							     band, NULL);
1013			if (sta) {
1014				u32 prev_rates;
1015
1016				prev_rates = sta->sta.supp_rates[band];
1017				/* make sure mandatory rates are always added */
1018				scan_width = NL80211_BSS_CHAN_WIDTH_20;
1019				if (rx_status->flag & RX_FLAG_5MHZ)
1020					scan_width = NL80211_BSS_CHAN_WIDTH_5;
1021				if (rx_status->flag & RX_FLAG_10MHZ)
1022					scan_width = NL80211_BSS_CHAN_WIDTH_10;
1023
1024				sta->sta.supp_rates[band] = supp_rates |
1025					ieee80211_mandatory_rates(sband,
1026								  scan_width);
1027				if (sta->sta.supp_rates[band] != prev_rates) {
1028					ibss_dbg(sdata,
1029						 "updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n",
1030						 sta->sta.addr, prev_rates,
1031						 sta->sta.supp_rates[band]);
1032					rates_updated = true;
1033				}
1034			} else {
1035				rcu_read_unlock();
1036				sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
1037						mgmt->sa, supp_rates);
1038			}
1039		}
1040
1041		if (sta && elems->wmm_info)
1042			sta->sta.wme = true;
1043
1044		if (sta && elems->ht_operation && elems->ht_cap_elem &&
1045		    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_20_NOHT &&
1046		    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_5 &&
1047		    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_10) {
1048			/* we both use HT */
1049			struct ieee80211_ht_cap htcap_ie;
1050			struct cfg80211_chan_def chandef;
1051
1052			ieee80211_ht_oper_to_chandef(channel,
1053						     elems->ht_operation,
1054						     &chandef);
1055
1056			memcpy(&htcap_ie, elems->ht_cap_elem, sizeof(htcap_ie));
1057
1058			/*
1059			 * fall back to HT20 if we don't use or use
1060			 * the other extension channel
1061			 */
1062			if (chandef.center_freq1 !=
1063			    sdata->u.ibss.chandef.center_freq1)
1064				htcap_ie.cap_info &=
1065					cpu_to_le16(~IEEE80211_HT_CAP_SUP_WIDTH_20_40);
1066
1067			rates_updated |= ieee80211_ht_cap_ie_to_sta_ht_cap(
1068						sdata, sband, &htcap_ie, sta);
1069		}
1070
1071		if (sta && rates_updated) {
1072			drv_sta_rc_update(local, sdata, &sta->sta,
1073					  IEEE80211_RC_SUPP_RATES_CHANGED);
1074			rate_control_rate_init(sta);
1075		}
1076
1077		rcu_read_unlock();
1078	}
1079
1080	bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
1081					channel);
1082	if (!bss)
1083		return;
1084
1085	cbss = container_of((void *)bss, struct cfg80211_bss, priv);
1086
1087	/* same for beacon and probe response */
1088	beacon_timestamp = le64_to_cpu(mgmt->u.beacon.timestamp);
1089
1090	/* check if we need to merge IBSS */
1091
1092	/* not an IBSS */
1093	if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
1094		goto put_bss;
1095
1096	/* different channel */
1097	if (sdata->u.ibss.fixed_channel &&
1098	    sdata->u.ibss.chandef.chan != cbss->channel)
1099		goto put_bss;
1100
1101	/* different SSID */
1102	if (elems->ssid_len != sdata->u.ibss.ssid_len ||
1103	    memcmp(elems->ssid, sdata->u.ibss.ssid,
1104				sdata->u.ibss.ssid_len))
1105		goto put_bss;
1106
1107	/* process channel switch */
1108	if (sdata->vif.csa_active ||
1109	    ieee80211_ibss_process_chanswitch(sdata, elems, true))
1110		goto put_bss;
1111
1112	/* same BSSID */
1113	if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid))
1114		goto put_bss;
1115
1116	/* we use a fixed BSSID */
1117	if (sdata->u.ibss.fixed_bssid)
1118		goto put_bss;
1119
1120	if (ieee80211_have_rx_timestamp(rx_status)) {
1121		/* time when timestamp field was received */
1122		rx_timestamp =
1123			ieee80211_calculate_rx_timestamp(local, rx_status,
1124							 len + FCS_LEN, 24);
1125	} else {
1126		/*
1127		 * second best option: get current TSF
1128		 * (will return -1 if not supported)
1129		 */
1130		rx_timestamp = drv_get_tsf(local, sdata);
1131	}
1132
1133	ibss_dbg(sdata,
1134		 "RX beacon SA=%pM BSSID=%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
1135		 mgmt->sa, mgmt->bssid,
1136		 (unsigned long long)rx_timestamp,
1137		 (unsigned long long)beacon_timestamp,
1138		 (unsigned long long)(rx_timestamp - beacon_timestamp),
1139		 jiffies);
1140
1141	if (beacon_timestamp > rx_timestamp) {
1142		ibss_dbg(sdata,
1143			 "beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n",
1144			 mgmt->bssid);
1145		ieee80211_sta_join_ibss(sdata, bss);
1146		supp_rates = ieee80211_sta_get_rates(sdata, elems, band, NULL);
1147		ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
1148				       supp_rates);
1149		rcu_read_unlock();
1150	}
1151
1152 put_bss:
1153	ieee80211_rx_bss_put(local, bss);
1154}
1155
1156void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata,
1157			      const u8 *bssid, const u8 *addr,
1158			      u32 supp_rates)
1159{
1160	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1161	struct ieee80211_local *local = sdata->local;
1162	struct sta_info *sta;
1163	struct ieee80211_chanctx_conf *chanctx_conf;
1164	struct ieee80211_supported_band *sband;
1165	enum nl80211_bss_scan_width scan_width;
1166	int band;
1167
1168	/*
1169	 * XXX: Consider removing the least recently used entry and
1170	 * 	allow new one to be added.
1171	 */
1172	if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
1173		net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
1174				    sdata->name, addr);
1175		return;
1176	}
1177
1178	if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
1179		return;
1180
1181	if (!ether_addr_equal(bssid, sdata->u.ibss.bssid))
1182		return;
1183
1184	rcu_read_lock();
1185	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
1186	if (WARN_ON_ONCE(!chanctx_conf)) {
1187		rcu_read_unlock();
1188		return;
1189	}
1190	band = chanctx_conf->def.chan->band;
1191	scan_width = cfg80211_chandef_to_scan_width(&chanctx_conf->def);
1192	rcu_read_unlock();
1193
1194	sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
1195	if (!sta)
1196		return;
1197
1198	sta->last_rx = jiffies;
1199
1200	/* make sure mandatory rates are always added */
1201	sband = local->hw.wiphy->bands[band];
1202	sta->sta.supp_rates[band] = supp_rates |
1203			ieee80211_mandatory_rates(sband, scan_width);
1204
1205	spin_lock(&ifibss->incomplete_lock);
1206	list_add(&sta->list, &ifibss->incomplete_stations);
1207	spin_unlock(&ifibss->incomplete_lock);
1208	ieee80211_queue_work(&local->hw, &sdata->work);
1209}
1210
1211static void ieee80211_ibss_sta_expire(struct ieee80211_sub_if_data *sdata)
1212{
1213	struct ieee80211_local *local = sdata->local;
1214	struct sta_info *sta, *tmp;
1215	unsigned long exp_time = IEEE80211_IBSS_INACTIVITY_LIMIT;
1216	unsigned long exp_rsn_time = IEEE80211_IBSS_RSN_INACTIVITY_LIMIT;
1217
1218	mutex_lock(&local->sta_mtx);
1219
1220	list_for_each_entry_safe(sta, tmp, &local->sta_list, list) {
1221		if (sdata != sta->sdata)
1222			continue;
1223
1224		if (time_after(jiffies, sta->last_rx + exp_time) ||
1225		    (time_after(jiffies, sta->last_rx + exp_rsn_time) &&
1226		     sta->sta_state != IEEE80211_STA_AUTHORIZED)) {
1227			sta_dbg(sta->sdata, "expiring inactive %sSTA %pM\n",
1228				sta->sta_state != IEEE80211_STA_AUTHORIZED ?
1229				"not authorized " : "", sta->sta.addr);
1230
1231			WARN_ON(__sta_info_destroy(sta));
1232		}
1233	}
1234
1235	mutex_unlock(&local->sta_mtx);
1236}
1237
1238/*
1239 * This function is called with state == IEEE80211_IBSS_MLME_JOINED
1240 */
1241
1242static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
1243{
1244	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1245	enum nl80211_bss_scan_width scan_width;
1246
1247	sdata_assert_lock(sdata);
1248
1249	mod_timer(&ifibss->timer,
1250		  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
1251
1252	ieee80211_ibss_sta_expire(sdata);
1253
1254	if (time_before(jiffies, ifibss->last_scan_completed +
1255		       IEEE80211_IBSS_MERGE_INTERVAL))
1256		return;
1257
1258	if (ieee80211_sta_active_ibss(sdata))
1259		return;
1260
1261	if (ifibss->fixed_channel)
1262		return;
1263
1264	sdata_info(sdata,
1265		   "No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n");
1266
1267	scan_width = cfg80211_chandef_to_scan_width(&ifibss->chandef);
1268	ieee80211_request_ibss_scan(sdata, ifibss->ssid, ifibss->ssid_len,
1269				    NULL, scan_width);
1270}
1271
1272static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
1273{
1274	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1275	u8 bssid[ETH_ALEN];
1276	u16 capability;
1277	int i;
1278
1279	sdata_assert_lock(sdata);
1280
1281	if (ifibss->fixed_bssid) {
1282		memcpy(bssid, ifibss->bssid, ETH_ALEN);
1283	} else {
1284		/* Generate random, not broadcast, locally administered BSSID. Mix in
1285		 * own MAC address to make sure that devices that do not have proper
1286		 * random number generator get different BSSID. */
1287		get_random_bytes(bssid, ETH_ALEN);
1288		for (i = 0; i < ETH_ALEN; i++)
1289			bssid[i] ^= sdata->vif.addr[i];
1290		bssid[0] &= ~0x01;
1291		bssid[0] |= 0x02;
1292	}
1293
1294	sdata_info(sdata, "Creating new IBSS network, BSSID %pM\n", bssid);
1295
1296	capability = WLAN_CAPABILITY_IBSS;
1297
1298	if (ifibss->privacy)
1299		capability |= WLAN_CAPABILITY_PRIVACY;
1300	else
1301		sdata->drop_unencrypted = 0;
1302
1303	__ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
1304				  &ifibss->chandef, ifibss->basic_rates,
1305				  capability, 0, true);
1306}
1307
1308/*
1309 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
1310 */
1311
1312static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
1313{
1314	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1315	struct ieee80211_local *local = sdata->local;
1316	struct cfg80211_bss *cbss;
1317	struct ieee80211_channel *chan = NULL;
1318	const u8 *bssid = NULL;
1319	enum nl80211_bss_scan_width scan_width;
1320	int active_ibss;
1321	u16 capability;
1322
1323	sdata_assert_lock(sdata);
1324
1325	active_ibss = ieee80211_sta_active_ibss(sdata);
1326	ibss_dbg(sdata, "sta_find_ibss (active_ibss=%d)\n", active_ibss);
1327
1328	if (active_ibss)
1329		return;
1330
1331	capability = WLAN_CAPABILITY_IBSS;
1332	if (ifibss->privacy)
1333		capability |= WLAN_CAPABILITY_PRIVACY;
1334	if (ifibss->fixed_bssid)
1335		bssid = ifibss->bssid;
1336	if (ifibss->fixed_channel)
1337		chan = ifibss->chandef.chan;
1338	if (!is_zero_ether_addr(ifibss->bssid))
1339		bssid = ifibss->bssid;
1340	cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
1341				ifibss->ssid, ifibss->ssid_len,
1342				WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
1343				capability);
1344
1345	if (cbss) {
1346		struct ieee80211_bss *bss;
1347
1348		bss = (void *)cbss->priv;
1349		ibss_dbg(sdata,
1350			 "sta_find_ibss: selected %pM current %pM\n",
1351			 cbss->bssid, ifibss->bssid);
1352		sdata_info(sdata,
1353			   "Selected IBSS BSSID %pM based on configured SSID\n",
1354			   cbss->bssid);
1355
1356		ieee80211_sta_join_ibss(sdata, bss);
1357		ieee80211_rx_bss_put(local, bss);
1358		return;
1359	}
1360
1361	/* if a fixed bssid and a fixed freq have been provided create the IBSS
1362	 * directly and do not waste time scanning
1363	 */
1364	if (ifibss->fixed_bssid && ifibss->fixed_channel) {
1365		sdata_info(sdata, "Created IBSS using preconfigured BSSID %pM\n",
1366			   bssid);
1367		ieee80211_sta_create_ibss(sdata);
1368		return;
1369	}
1370
1371
1372	ibss_dbg(sdata, "sta_find_ibss: did not try to join ibss\n");
1373
1374	/* Selected IBSS not found in current scan results - try to scan */
1375	if (time_after(jiffies, ifibss->last_scan_completed +
1376					IEEE80211_SCAN_INTERVAL)) {
1377		sdata_info(sdata, "Trigger new scan to find an IBSS to join\n");
1378
1379		scan_width = cfg80211_chandef_to_scan_width(&ifibss->chandef);
1380		ieee80211_request_ibss_scan(sdata, ifibss->ssid,
1381					    ifibss->ssid_len, chan,
1382					    scan_width);
1383	} else {
1384		int interval = IEEE80211_SCAN_INTERVAL;
1385
1386		if (time_after(jiffies, ifibss->ibss_join_req +
1387			       IEEE80211_IBSS_JOIN_TIMEOUT))
1388			ieee80211_sta_create_ibss(sdata);
1389
1390		mod_timer(&ifibss->timer,
1391			  round_jiffies(jiffies + interval));
1392	}
1393}
1394
1395static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
1396					struct sk_buff *req)
1397{
1398	struct ieee80211_mgmt *mgmt = (void *)req->data;
1399	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1400	struct ieee80211_local *local = sdata->local;
1401	int tx_last_beacon, len = req->len;
1402	struct sk_buff *skb;
1403	struct beacon_data *presp;
1404	u8 *pos, *end;
1405
1406	sdata_assert_lock(sdata);
1407
1408	presp = rcu_dereference_protected(ifibss->presp,
1409					  lockdep_is_held(&sdata->wdev.mtx));
1410
1411	if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
1412	    len < 24 + 2 || !presp)
1413		return;
1414
1415	tx_last_beacon = drv_tx_last_beacon(local);
1416
1417	ibss_dbg(sdata,
1418		 "RX ProbeReq SA=%pM DA=%pM BSSID=%pM (tx_last_beacon=%d)\n",
1419		 mgmt->sa, mgmt->da, mgmt->bssid, tx_last_beacon);
1420
1421	if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da))
1422		return;
1423
1424	if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) &&
1425	    !is_broadcast_ether_addr(mgmt->bssid))
1426		return;
1427
1428	end = ((u8 *) mgmt) + len;
1429	pos = mgmt->u.probe_req.variable;
1430	if (pos[0] != WLAN_EID_SSID ||
1431	    pos + 2 + pos[1] > end) {
1432		ibss_dbg(sdata, "Invalid SSID IE in ProbeReq from %pM\n",
1433			 mgmt->sa);
1434		return;
1435	}
1436	if (pos[1] != 0 &&
1437	    (pos[1] != ifibss->ssid_len ||
1438	     memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
1439		/* Ignore ProbeReq for foreign SSID */
1440		return;
1441	}
1442
1443	/* Reply with ProbeResp */
1444	skb = dev_alloc_skb(local->tx_headroom + presp->head_len);
1445	if (!skb)
1446		return;
1447
1448	skb_reserve(skb, local->tx_headroom);
1449	memcpy(skb_put(skb, presp->head_len), presp->head, presp->head_len);
1450
1451	memcpy(((struct ieee80211_mgmt *) skb->data)->da, mgmt->sa, ETH_ALEN);
1452	ibss_dbg(sdata, "Sending ProbeResp to %pM\n", mgmt->sa);
1453	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
1454
1455	/* avoid excessive retries for probe request to wildcard SSIDs */
1456	if (pos[1] == 0)
1457		IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_NO_ACK;
1458
1459	ieee80211_tx_skb(sdata, skb);
1460}
1461
1462static
1463void ieee80211_rx_mgmt_probe_beacon(struct ieee80211_sub_if_data *sdata,
1464				    struct ieee80211_mgmt *mgmt, size_t len,
1465				    struct ieee80211_rx_status *rx_status)
1466{
1467	size_t baselen;
1468	struct ieee802_11_elems elems;
1469
1470	BUILD_BUG_ON(offsetof(typeof(mgmt->u.probe_resp), variable) !=
1471		     offsetof(typeof(mgmt->u.beacon), variable));
1472
1473	/*
1474	 * either beacon or probe_resp but the variable field is at the
1475	 * same offset
1476	 */
1477	baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
1478	if (baselen > len)
1479		return;
1480
1481	ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
1482			       false, &elems);
1483
1484	ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems);
1485}
1486
1487void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
1488				   struct sk_buff *skb)
1489{
1490	struct ieee80211_rx_status *rx_status;
1491	struct ieee80211_mgmt *mgmt;
1492	u16 fc;
1493	struct ieee802_11_elems elems;
1494	int ies_len;
1495
1496	rx_status = IEEE80211_SKB_RXCB(skb);
1497	mgmt = (struct ieee80211_mgmt *) skb->data;
1498	fc = le16_to_cpu(mgmt->frame_control);
1499
1500	sdata_lock(sdata);
1501
1502	if (!sdata->u.ibss.ssid_len)
1503		goto mgmt_out; /* not ready to merge yet */
1504
1505	switch (fc & IEEE80211_FCTL_STYPE) {
1506	case IEEE80211_STYPE_PROBE_REQ:
1507		ieee80211_rx_mgmt_probe_req(sdata, skb);
1508		break;
1509	case IEEE80211_STYPE_PROBE_RESP:
1510	case IEEE80211_STYPE_BEACON:
1511		ieee80211_rx_mgmt_probe_beacon(sdata, mgmt, skb->len,
1512					       rx_status);
1513		break;
1514	case IEEE80211_STYPE_AUTH:
1515		ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
1516		break;
1517	case IEEE80211_STYPE_DEAUTH:
1518		ieee80211_rx_mgmt_deauth_ibss(sdata, mgmt, skb->len);
1519		break;
1520	case IEEE80211_STYPE_ACTION:
1521		switch (mgmt->u.action.category) {
1522		case WLAN_CATEGORY_SPECTRUM_MGMT:
1523			ies_len = skb->len -
1524				  offsetof(struct ieee80211_mgmt,
1525					   u.action.u.chan_switch.variable);
1526
1527			if (ies_len < 0)
1528				break;
1529
1530			ieee802_11_parse_elems(
1531				mgmt->u.action.u.chan_switch.variable,
1532				ies_len, true, &elems);
1533
1534			if (elems.parse_error)
1535				break;
1536
1537			ieee80211_rx_mgmt_spectrum_mgmt(sdata, mgmt, skb->len,
1538							rx_status, &elems);
1539			break;
1540		}
1541	}
1542
1543 mgmt_out:
1544	sdata_unlock(sdata);
1545}
1546
1547void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
1548{
1549	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1550	struct sta_info *sta;
1551
1552	sdata_lock(sdata);
1553
1554	/*
1555	 * Work could be scheduled after scan or similar
1556	 * when we aren't even joined (or trying) with a
1557	 * network.
1558	 */
1559	if (!ifibss->ssid_len)
1560		goto out;
1561
1562	spin_lock_bh(&ifibss->incomplete_lock);
1563	while (!list_empty(&ifibss->incomplete_stations)) {
1564		sta = list_first_entry(&ifibss->incomplete_stations,
1565				       struct sta_info, list);
1566		list_del(&sta->list);
1567		spin_unlock_bh(&ifibss->incomplete_lock);
1568
1569		ieee80211_ibss_finish_sta(sta);
1570		rcu_read_unlock();
1571		spin_lock_bh(&ifibss->incomplete_lock);
1572	}
1573	spin_unlock_bh(&ifibss->incomplete_lock);
1574
1575	switch (ifibss->state) {
1576	case IEEE80211_IBSS_MLME_SEARCH:
1577		ieee80211_sta_find_ibss(sdata);
1578		break;
1579	case IEEE80211_IBSS_MLME_JOINED:
1580		ieee80211_sta_merge_ibss(sdata);
1581		break;
1582	default:
1583		WARN_ON(1);
1584		break;
1585	}
1586
1587 out:
1588	sdata_unlock(sdata);
1589}
1590
1591static void ieee80211_ibss_timer(unsigned long data)
1592{
1593	struct ieee80211_sub_if_data *sdata =
1594		(struct ieee80211_sub_if_data *) data;
1595
1596	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
1597}
1598
1599void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
1600{
1601	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1602
1603	setup_timer(&ifibss->timer, ieee80211_ibss_timer,
1604		    (unsigned long) sdata);
1605	INIT_LIST_HEAD(&ifibss->incomplete_stations);
1606	spin_lock_init(&ifibss->incomplete_lock);
1607	INIT_WORK(&ifibss->csa_connection_drop_work,
1608		  ieee80211_csa_connection_drop_work);
1609}
1610
1611/* scan finished notification */
1612void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
1613{
1614	struct ieee80211_sub_if_data *sdata;
1615
1616	mutex_lock(&local->iflist_mtx);
1617	list_for_each_entry(sdata, &local->interfaces, list) {
1618		if (!ieee80211_sdata_running(sdata))
1619			continue;
1620		if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
1621			continue;
1622		sdata->u.ibss.last_scan_completed = jiffies;
1623		ieee80211_queue_work(&local->hw, &sdata->work);
1624	}
1625	mutex_unlock(&local->iflist_mtx);
1626}
1627
1628int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
1629			struct cfg80211_ibss_params *params)
1630{
1631	u32 changed = 0;
1632	u32 rate_flags;
1633	struct ieee80211_supported_band *sband;
1634	enum ieee80211_chanctx_mode chanmode;
1635	struct ieee80211_local *local = sdata->local;
1636	int radar_detect_width = 0;
1637	int i;
1638	int ret;
1639
1640	ret = cfg80211_chandef_dfs_required(local->hw.wiphy,
1641					    &params->chandef,
1642					    sdata->wdev.iftype);
1643	if (ret < 0)
1644		return ret;
1645
1646	if (ret > 0) {
1647		if (!params->userspace_handles_dfs)
1648			return -EINVAL;
1649		radar_detect_width = BIT(params->chandef.width);
1650	}
1651
1652	chanmode = (params->channel_fixed && !ret) ?
1653		IEEE80211_CHANCTX_SHARED : IEEE80211_CHANCTX_EXCLUSIVE;
1654
1655	mutex_lock(&local->chanctx_mtx);
1656	ret = ieee80211_check_combinations(sdata, &params->chandef, chanmode,
1657					   radar_detect_width);
1658	mutex_unlock(&local->chanctx_mtx);
1659	if (ret < 0)
1660		return ret;
1661
1662	if (params->bssid) {
1663		memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
1664		sdata->u.ibss.fixed_bssid = true;
1665	} else
1666		sdata->u.ibss.fixed_bssid = false;
1667
1668	sdata->u.ibss.privacy = params->privacy;
1669	sdata->u.ibss.control_port = params->control_port;
1670	sdata->u.ibss.userspace_handles_dfs = params->userspace_handles_dfs;
1671	sdata->u.ibss.basic_rates = params->basic_rates;
1672	sdata->u.ibss.last_scan_completed = jiffies;
1673
1674	/* fix basic_rates if channel does not support these rates */
1675	rate_flags = ieee80211_chandef_rate_flags(&params->chandef);
1676	sband = local->hw.wiphy->bands[params->chandef.chan->band];
1677	for (i = 0; i < sband->n_bitrates; i++) {
1678		if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
1679			sdata->u.ibss.basic_rates &= ~BIT(i);
1680	}
1681	memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate,
1682	       sizeof(params->mcast_rate));
1683
1684	sdata->vif.bss_conf.beacon_int = params->beacon_interval;
1685
1686	sdata->u.ibss.chandef = params->chandef;
1687	sdata->u.ibss.fixed_channel = params->channel_fixed;
1688
1689	if (params->ie) {
1690		sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
1691					   GFP_KERNEL);
1692		if (sdata->u.ibss.ie)
1693			sdata->u.ibss.ie_len = params->ie_len;
1694	}
1695
1696	sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
1697	sdata->u.ibss.ibss_join_req = jiffies;
1698
1699	memcpy(sdata->u.ibss.ssid, params->ssid, params->ssid_len);
1700	sdata->u.ibss.ssid_len = params->ssid_len;
1701
1702	memcpy(&sdata->u.ibss.ht_capa, &params->ht_capa,
1703	       sizeof(sdata->u.ibss.ht_capa));
1704	memcpy(&sdata->u.ibss.ht_capa_mask, &params->ht_capa_mask,
1705	       sizeof(sdata->u.ibss.ht_capa_mask));
1706
1707	/*
1708	 * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is
1709	 * reserved, but an HT STA shall protect HT transmissions as though
1710	 * the HT Protection field were set to non-HT mixed mode.
1711	 *
1712	 * In an IBSS, the RIFS Mode field of the HT Operation element is
1713	 * also reserved, but an HT STA shall operate as though this field
1714	 * were set to 1.
1715	 */
1716
1717	sdata->vif.bss_conf.ht_operation_mode |=
1718		  IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED
1719		| IEEE80211_HT_PARAM_RIFS_MODE;
1720
1721	changed |= BSS_CHANGED_HT;
1722	ieee80211_bss_info_change_notify(sdata, changed);
1723
1724	sdata->smps_mode = IEEE80211_SMPS_OFF;
1725	sdata->needed_rx_chains = local->rx_chains;
1726
1727	ieee80211_queue_work(&local->hw, &sdata->work);
1728
1729	return 0;
1730}
1731
1732int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
1733{
1734	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1735
1736	ieee80211_ibss_disconnect(sdata);
1737	ifibss->ssid_len = 0;
1738	memset(ifibss->bssid, 0, ETH_ALEN);
1739
1740	/* remove beacon */
1741	kfree(sdata->u.ibss.ie);
1742
1743	/* on the next join, re-program HT parameters */
1744	memset(&ifibss->ht_capa, 0, sizeof(ifibss->ht_capa));
1745	memset(&ifibss->ht_capa_mask, 0, sizeof(ifibss->ht_capa_mask));
1746
1747	synchronize_rcu();
1748
1749	skb_queue_purge(&sdata->skb_queue);
1750
1751	del_timer_sync(&sdata->u.ibss.timer);
1752
1753	return 0;
1754}
1755