ibss.c revision f1249700f563b5dc541afa7e54a2d93fdffc1fb6
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 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
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#include <asm/unaligned.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_SCAN_INTERVAL_SLOW (15 * HZ)
31#define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)
32
33#define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
34#define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)
35
36#define IEEE80211_IBSS_MAX_STA_ENTRIES 128
37
38
39static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
40					struct ieee80211_mgmt *mgmt,
41					size_t len)
42{
43	u16 auth_alg, auth_transaction;
44
45	lockdep_assert_held(&sdata->u.ibss.mtx);
46
47	if (len < 24 + 6)
48		return;
49
50	auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
51	auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
52
53	/*
54	 * IEEE 802.11 standard does not require authentication in IBSS
55	 * networks and most implementations do not seem to use it.
56	 * However, try to reply to authentication attempts if someone
57	 * has actually implemented this.
58	 */
59	if (auth_alg == WLAN_AUTH_OPEN && auth_transaction == 1)
60		ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0, mgmt->sa,
61				    sdata->u.ibss.bssid, NULL, 0, 0);
62}
63
64static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
65				      const u8 *bssid, const int beacon_int,
66				      struct ieee80211_channel *chan,
67				      const u32 basic_rates,
68				      const u16 capability, u64 tsf)
69{
70	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
71	struct ieee80211_local *local = sdata->local;
72	int rates, i;
73	struct sk_buff *skb;
74	struct ieee80211_mgmt *mgmt;
75	u8 *pos;
76	struct ieee80211_supported_band *sband;
77	struct cfg80211_bss *bss;
78	u32 bss_change;
79	u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
80	enum nl80211_channel_type channel_type;
81
82	lockdep_assert_held(&ifibss->mtx);
83
84	/* Reset own TSF to allow time synchronization work. */
85	drv_reset_tsf(local, sdata);
86
87	skb = ifibss->skb;
88	RCU_INIT_POINTER(ifibss->presp, NULL);
89	synchronize_rcu();
90	skb->data = skb->head;
91	skb->len = 0;
92	skb_reset_tail_pointer(skb);
93	skb_reserve(skb, sdata->local->hw.extra_tx_headroom);
94
95	if (memcmp(ifibss->bssid, bssid, ETH_ALEN))
96		sta_info_flush(sdata->local, sdata);
97
98	/* if merging, indicate to driver that we leave the old IBSS */
99	if (sdata->vif.bss_conf.ibss_joined) {
100		sdata->vif.bss_conf.ibss_joined = false;
101		netif_carrier_off(sdata->dev);
102		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IBSS);
103	}
104
105	memcpy(ifibss->bssid, bssid, ETH_ALEN);
106
107	sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
108
109	channel_type = ifibss->channel_type;
110	if (channel_type > NL80211_CHAN_HT20 &&
111	    !cfg80211_can_beacon_sec_chan(local->hw.wiphy, chan, channel_type))
112		channel_type = NL80211_CHAN_HT20;
113	if (!ieee80211_set_channel_type(local, sdata, channel_type)) {
114		/* can only fail due to HT40+/- mismatch */
115		channel_type = NL80211_CHAN_HT20;
116		WARN_ON(!ieee80211_set_channel_type(local, sdata,
117						    NL80211_CHAN_HT20));
118	}
119	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
120
121	sband = local->hw.wiphy->bands[chan->band];
122
123	/* build supported rates array */
124	pos = supp_rates;
125	for (i = 0; i < sband->n_bitrates; i++) {
126		int rate = sband->bitrates[i].bitrate;
127		u8 basic = 0;
128		if (basic_rates & BIT(i))
129			basic = 0x80;
130		*pos++ = basic | (u8) (rate / 5);
131	}
132
133	/* Build IBSS probe response */
134	mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon));
135	memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
136	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
137					  IEEE80211_STYPE_PROBE_RESP);
138	memset(mgmt->da, 0xff, ETH_ALEN);
139	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
140	memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
141	mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
142	mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
143	mgmt->u.beacon.capab_info = cpu_to_le16(capability);
144
145	pos = skb_put(skb, 2 + ifibss->ssid_len);
146	*pos++ = WLAN_EID_SSID;
147	*pos++ = ifibss->ssid_len;
148	memcpy(pos, ifibss->ssid, ifibss->ssid_len);
149
150	rates = sband->n_bitrates;
151	if (rates > 8)
152		rates = 8;
153	pos = skb_put(skb, 2 + rates);
154	*pos++ = WLAN_EID_SUPP_RATES;
155	*pos++ = rates;
156	memcpy(pos, supp_rates, rates);
157
158	if (sband->band == IEEE80211_BAND_2GHZ) {
159		pos = skb_put(skb, 2 + 1);
160		*pos++ = WLAN_EID_DS_PARAMS;
161		*pos++ = 1;
162		*pos++ = ieee80211_frequency_to_channel(chan->center_freq);
163	}
164
165	pos = skb_put(skb, 2 + 2);
166	*pos++ = WLAN_EID_IBSS_PARAMS;
167	*pos++ = 2;
168	/* FIX: set ATIM window based on scan results */
169	*pos++ = 0;
170	*pos++ = 0;
171
172	if (sband->n_bitrates > 8) {
173		rates = sband->n_bitrates - 8;
174		pos = skb_put(skb, 2 + rates);
175		*pos++ = WLAN_EID_EXT_SUPP_RATES;
176		*pos++ = rates;
177		memcpy(pos, &supp_rates[8], rates);
178	}
179
180	if (ifibss->ie_len)
181		memcpy(skb_put(skb, ifibss->ie_len),
182		       ifibss->ie, ifibss->ie_len);
183
184	/* add HT capability and information IEs */
185	if (channel_type && sband->ht_cap.ht_supported) {
186		pos = skb_put(skb, 4 +
187				   sizeof(struct ieee80211_ht_cap) +
188				   sizeof(struct ieee80211_ht_info));
189		pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap,
190						sband->ht_cap.cap);
191		pos = ieee80211_ie_build_ht_info(pos,
192						 &sband->ht_cap,
193						 chan,
194						 channel_type);
195	}
196
197	if (local->hw.queues >= 4) {
198		pos = skb_put(skb, 9);
199		*pos++ = WLAN_EID_VENDOR_SPECIFIC;
200		*pos++ = 7; /* len */
201		*pos++ = 0x00; /* Microsoft OUI 00:50:F2 */
202		*pos++ = 0x50;
203		*pos++ = 0xf2;
204		*pos++ = 2; /* WME */
205		*pos++ = 0; /* WME info */
206		*pos++ = 1; /* WME ver */
207		*pos++ = 0; /* U-APSD no in use */
208	}
209
210	rcu_assign_pointer(ifibss->presp, skb);
211
212	sdata->vif.bss_conf.beacon_int = beacon_int;
213	sdata->vif.bss_conf.basic_rates = basic_rates;
214	bss_change = BSS_CHANGED_BEACON_INT;
215	bss_change |= ieee80211_reset_erp_info(sdata);
216	bss_change |= BSS_CHANGED_BSSID;
217	bss_change |= BSS_CHANGED_BEACON;
218	bss_change |= BSS_CHANGED_BEACON_ENABLED;
219	bss_change |= BSS_CHANGED_BASIC_RATES;
220	bss_change |= BSS_CHANGED_HT;
221	bss_change |= BSS_CHANGED_IBSS;
222	sdata->vif.bss_conf.ibss_joined = true;
223	ieee80211_bss_info_change_notify(sdata, bss_change);
224
225	ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates);
226
227	ifibss->state = IEEE80211_IBSS_MLME_JOINED;
228	mod_timer(&ifibss->timer,
229		  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
230
231	bss = cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel,
232					mgmt, skb->len, 0, GFP_KERNEL);
233	cfg80211_put_bss(bss);
234	netif_carrier_on(sdata->dev);
235	cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
236}
237
238static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
239				    struct ieee80211_bss *bss)
240{
241	struct cfg80211_bss *cbss =
242		container_of((void *)bss, struct cfg80211_bss, priv);
243	struct ieee80211_supported_band *sband;
244	u32 basic_rates;
245	int i, j;
246	u16 beacon_int = cbss->beacon_interval;
247
248	lockdep_assert_held(&sdata->u.ibss.mtx);
249
250	if (beacon_int < 10)
251		beacon_int = 10;
252
253	sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
254
255	basic_rates = 0;
256
257	for (i = 0; i < bss->supp_rates_len; i++) {
258		int rate = (bss->supp_rates[i] & 0x7f) * 5;
259		bool is_basic = !!(bss->supp_rates[i] & 0x80);
260
261		for (j = 0; j < sband->n_bitrates; j++) {
262			if (sband->bitrates[j].bitrate == rate) {
263				if (is_basic)
264					basic_rates |= BIT(j);
265				break;
266			}
267		}
268	}
269
270	__ieee80211_sta_join_ibss(sdata, cbss->bssid,
271				  beacon_int,
272				  cbss->channel,
273				  basic_rates,
274				  cbss->capability,
275				  cbss->tsf);
276}
277
278static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta)
279	__acquires(RCU)
280{
281	struct ieee80211_sub_if_data *sdata = sta->sdata;
282	u8 addr[ETH_ALEN];
283
284	memcpy(addr, sta->sta.addr, ETH_ALEN);
285
286#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
287	wiphy_debug(sdata->local->hw.wiphy,
288		    "Adding new IBSS station %pM (dev=%s)\n",
289		    addr, sdata->name);
290#endif
291
292	sta_info_move_state(sta, IEEE80211_STA_AUTH);
293	sta_info_move_state(sta, IEEE80211_STA_ASSOC);
294	sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);
295
296	rate_control_rate_init(sta);
297
298	/* If it fails, maybe we raced another insertion? */
299	if (sta_info_insert_rcu(sta))
300		return sta_info_get(sdata, addr);
301	return sta;
302}
303
304static struct sta_info *
305ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
306		       const u8 *bssid, const u8 *addr,
307		       u32 supp_rates)
308	__acquires(RCU)
309{
310	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
311	struct ieee80211_local *local = sdata->local;
312	struct sta_info *sta;
313	int band = local->hw.conf.channel->band;
314
315	/*
316	 * XXX: Consider removing the least recently used entry and
317	 * 	allow new one to be added.
318	 */
319	if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
320		if (net_ratelimit())
321			printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
322			       sdata->name, addr);
323		rcu_read_lock();
324		return NULL;
325	}
326
327	if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) {
328		rcu_read_lock();
329		return NULL;
330	}
331
332	if (compare_ether_addr(bssid, sdata->u.ibss.bssid)) {
333		rcu_read_lock();
334		return NULL;
335	}
336
337	sta = sta_info_alloc(sdata, addr, GFP_KERNEL);
338	if (!sta) {
339		rcu_read_lock();
340		return NULL;
341	}
342
343	sta->last_rx = jiffies;
344
345	/* make sure mandatory rates are always added */
346	sta->sta.supp_rates[band] = supp_rates |
347			ieee80211_mandatory_rates(local, band);
348
349	return ieee80211_ibss_finish_sta(sta);
350}
351
352static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
353				  struct ieee80211_mgmt *mgmt,
354				  size_t len,
355				  struct ieee80211_rx_status *rx_status,
356				  struct ieee802_11_elems *elems,
357				  bool beacon)
358{
359	struct ieee80211_local *local = sdata->local;
360	int freq;
361	struct cfg80211_bss *cbss;
362	struct ieee80211_bss *bss;
363	struct sta_info *sta;
364	struct ieee80211_channel *channel;
365	u64 beacon_timestamp, rx_timestamp;
366	u32 supp_rates = 0;
367	enum ieee80211_band band = rx_status->band;
368	struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
369	bool rates_updated = false;
370
371	if (elems->ds_params && elems->ds_params_len == 1)
372		freq = ieee80211_channel_to_frequency(elems->ds_params[0],
373						      band);
374	else
375		freq = rx_status->freq;
376
377	channel = ieee80211_get_channel(local->hw.wiphy, freq);
378
379	if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
380		return;
381
382	if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
383	    memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) {
384
385		rcu_read_lock();
386		sta = sta_info_get(sdata, mgmt->sa);
387
388		if (elems->supp_rates) {
389			supp_rates = ieee80211_sta_get_rates(local, elems,
390							     band);
391			if (sta) {
392				u32 prev_rates;
393
394				prev_rates = sta->sta.supp_rates[band];
395				/* make sure mandatory rates are always added */
396				sta->sta.supp_rates[band] = supp_rates |
397					ieee80211_mandatory_rates(local, band);
398
399				if (sta->sta.supp_rates[band] != prev_rates) {
400#ifdef CONFIG_MAC80211_IBSS_DEBUG
401					printk(KERN_DEBUG
402						"%s: updated supp_rates set "
403						"for %pM based on beacon"
404						"/probe_resp (0x%x -> 0x%x)\n",
405						sdata->name, sta->sta.addr,
406						prev_rates,
407						sta->sta.supp_rates[band]);
408#endif
409					rates_updated = true;
410				}
411			} else {
412				rcu_read_unlock();
413				sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
414						mgmt->sa, supp_rates);
415			}
416		}
417
418		if (sta && elems->wmm_info)
419			set_sta_flag(sta, WLAN_STA_WME);
420
421		if (sta && elems->ht_info_elem && elems->ht_cap_elem &&
422		    sdata->u.ibss.channel_type != NL80211_CHAN_NO_HT) {
423			/* we both use HT */
424			struct ieee80211_sta_ht_cap sta_ht_cap_new;
425			enum nl80211_channel_type channel_type =
426				ieee80211_ht_info_to_channel_type(
427							elems->ht_info_elem);
428
429			ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
430							  elems->ht_cap_elem,
431							  &sta_ht_cap_new);
432
433			/*
434			 * fall back to HT20 if we don't use or use
435			 * the other extension channel
436			 */
437			if ((channel_type == NL80211_CHAN_HT40MINUS ||
438			     channel_type == NL80211_CHAN_HT40PLUS) &&
439			    channel_type != sdata->u.ibss.channel_type)
440				sta_ht_cap_new.cap &=
441					~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
442
443			if (memcmp(&sta->sta.ht_cap, &sta_ht_cap_new,
444				   sizeof(sta_ht_cap_new))) {
445				memcpy(&sta->sta.ht_cap, &sta_ht_cap_new,
446				       sizeof(sta_ht_cap_new));
447				rates_updated = true;
448			}
449		}
450
451		if (sta && rates_updated)
452			rate_control_rate_init(sta);
453
454		rcu_read_unlock();
455	}
456
457	bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
458					channel, beacon);
459	if (!bss)
460		return;
461
462	cbss = container_of((void *)bss, struct cfg80211_bss, priv);
463
464	/* was just updated in ieee80211_bss_info_update */
465	beacon_timestamp = cbss->tsf;
466
467	/* check if we need to merge IBSS */
468
469	/* we use a fixed BSSID */
470	if (sdata->u.ibss.fixed_bssid)
471		goto put_bss;
472
473	/* not an IBSS */
474	if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
475		goto put_bss;
476
477	/* different channel */
478	if (cbss->channel != local->oper_channel)
479		goto put_bss;
480
481	/* different SSID */
482	if (elems->ssid_len != sdata->u.ibss.ssid_len ||
483	    memcmp(elems->ssid, sdata->u.ibss.ssid,
484				sdata->u.ibss.ssid_len))
485		goto put_bss;
486
487	/* same BSSID */
488	if (memcmp(cbss->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0)
489		goto put_bss;
490
491	if (rx_status->flag & RX_FLAG_MACTIME_MPDU) {
492		/*
493		 * For correct IBSS merging we need mactime; since mactime is
494		 * defined as the time the first data symbol of the frame hits
495		 * the PHY, and the timestamp of the beacon is defined as "the
496		 * time that the data symbol containing the first bit of the
497		 * timestamp is transmitted to the PHY plus the transmitting
498		 * STA's delays through its local PHY from the MAC-PHY
499		 * interface to its interface with the WM" (802.11 11.1.2)
500		 * - equals the time this bit arrives at the receiver - we have
501		 * to take into account the offset between the two.
502		 *
503		 * E.g. at 1 MBit that means mactime is 192 usec earlier
504		 * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
505		 */
506		int rate;
507
508		if (rx_status->flag & RX_FLAG_HT)
509			rate = 65; /* TODO: HT rates */
510		else
511			rate = local->hw.wiphy->bands[band]->
512				bitrates[rx_status->rate_idx].bitrate;
513
514		rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
515	} else {
516		/*
517		 * second best option: get current TSF
518		 * (will return -1 if not supported)
519		 */
520		rx_timestamp = drv_get_tsf(local, sdata);
521	}
522
523#ifdef CONFIG_MAC80211_IBSS_DEBUG
524	printk(KERN_DEBUG "RX beacon SA=%pM BSSID="
525	       "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
526	       mgmt->sa, mgmt->bssid,
527	       (unsigned long long)rx_timestamp,
528	       (unsigned long long)beacon_timestamp,
529	       (unsigned long long)(rx_timestamp - beacon_timestamp),
530	       jiffies);
531#endif
532
533	if (beacon_timestamp > rx_timestamp) {
534#ifdef CONFIG_MAC80211_IBSS_DEBUG
535		printk(KERN_DEBUG "%s: beacon TSF higher than "
536		       "local TSF - IBSS merge with BSSID %pM\n",
537		       sdata->name, mgmt->bssid);
538#endif
539		ieee80211_sta_join_ibss(sdata, bss);
540		supp_rates = ieee80211_sta_get_rates(local, elems, band);
541		ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
542				       supp_rates);
543		rcu_read_unlock();
544	}
545
546 put_bss:
547	ieee80211_rx_bss_put(local, bss);
548}
549
550void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata,
551			      const u8 *bssid, const u8 *addr,
552			      u32 supp_rates)
553{
554	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
555	struct ieee80211_local *local = sdata->local;
556	struct sta_info *sta;
557	int band = local->hw.conf.channel->band;
558
559	/*
560	 * XXX: Consider removing the least recently used entry and
561	 * 	allow new one to be added.
562	 */
563	if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
564		if (net_ratelimit())
565			printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
566			       sdata->name, addr);
567		return;
568	}
569
570	if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
571		return;
572
573	if (compare_ether_addr(bssid, sdata->u.ibss.bssid))
574		return;
575
576	sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
577	if (!sta)
578		return;
579
580	sta->last_rx = jiffies;
581
582	/* make sure mandatory rates are always added */
583	sta->sta.supp_rates[band] = supp_rates |
584			ieee80211_mandatory_rates(local, band);
585
586	spin_lock(&ifibss->incomplete_lock);
587	list_add(&sta->list, &ifibss->incomplete_stations);
588	spin_unlock(&ifibss->incomplete_lock);
589	ieee80211_queue_work(&local->hw, &sdata->work);
590}
591
592static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
593{
594	struct ieee80211_local *local = sdata->local;
595	int active = 0;
596	struct sta_info *sta;
597
598	lockdep_assert_held(&sdata->u.ibss.mtx);
599
600	rcu_read_lock();
601
602	list_for_each_entry_rcu(sta, &local->sta_list, list) {
603		if (sta->sdata == sdata &&
604		    time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
605			       jiffies)) {
606			active++;
607			break;
608		}
609	}
610
611	rcu_read_unlock();
612
613	return active;
614}
615
616/*
617 * This function is called with state == IEEE80211_IBSS_MLME_JOINED
618 */
619
620static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
621{
622	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
623
624	lockdep_assert_held(&ifibss->mtx);
625
626	mod_timer(&ifibss->timer,
627		  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
628
629	ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
630
631	if (time_before(jiffies, ifibss->last_scan_completed +
632		       IEEE80211_IBSS_MERGE_INTERVAL))
633		return;
634
635	if (ieee80211_sta_active_ibss(sdata))
636		return;
637
638	if (ifibss->fixed_channel)
639		return;
640
641	printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
642	       "IBSS networks with same SSID (merge)\n", sdata->name);
643
644	ieee80211_request_internal_scan(sdata,
645			ifibss->ssid, ifibss->ssid_len, NULL);
646}
647
648static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
649{
650	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
651	u8 bssid[ETH_ALEN];
652	u16 capability;
653	int i;
654
655	lockdep_assert_held(&ifibss->mtx);
656
657	if (ifibss->fixed_bssid) {
658		memcpy(bssid, ifibss->bssid, ETH_ALEN);
659	} else {
660		/* Generate random, not broadcast, locally administered BSSID. Mix in
661		 * own MAC address to make sure that devices that do not have proper
662		 * random number generator get different BSSID. */
663		get_random_bytes(bssid, ETH_ALEN);
664		for (i = 0; i < ETH_ALEN; i++)
665			bssid[i] ^= sdata->vif.addr[i];
666		bssid[0] &= ~0x01;
667		bssid[0] |= 0x02;
668	}
669
670	printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n",
671	       sdata->name, bssid);
672
673	capability = WLAN_CAPABILITY_IBSS;
674
675	if (ifibss->privacy)
676		capability |= WLAN_CAPABILITY_PRIVACY;
677	else
678		sdata->drop_unencrypted = 0;
679
680	__ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
681				  ifibss->channel, ifibss->basic_rates,
682				  capability, 0);
683}
684
685/*
686 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
687 */
688
689static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
690{
691	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
692	struct ieee80211_local *local = sdata->local;
693	struct cfg80211_bss *cbss;
694	struct ieee80211_channel *chan = NULL;
695	const u8 *bssid = NULL;
696	int active_ibss;
697	u16 capability;
698
699	lockdep_assert_held(&ifibss->mtx);
700
701	active_ibss = ieee80211_sta_active_ibss(sdata);
702#ifdef CONFIG_MAC80211_IBSS_DEBUG
703	printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n",
704	       sdata->name, active_ibss);
705#endif /* CONFIG_MAC80211_IBSS_DEBUG */
706
707	if (active_ibss)
708		return;
709
710	capability = WLAN_CAPABILITY_IBSS;
711	if (ifibss->privacy)
712		capability |= WLAN_CAPABILITY_PRIVACY;
713	if (ifibss->fixed_bssid)
714		bssid = ifibss->bssid;
715	if (ifibss->fixed_channel)
716		chan = ifibss->channel;
717	if (!is_zero_ether_addr(ifibss->bssid))
718		bssid = ifibss->bssid;
719	cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
720				ifibss->ssid, ifibss->ssid_len,
721				WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
722				capability);
723
724	if (cbss) {
725		struct ieee80211_bss *bss;
726
727		bss = (void *)cbss->priv;
728#ifdef CONFIG_MAC80211_IBSS_DEBUG
729		printk(KERN_DEBUG "   sta_find_ibss: selected %pM current "
730		       "%pM\n", cbss->bssid, ifibss->bssid);
731#endif /* CONFIG_MAC80211_IBSS_DEBUG */
732
733		printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM"
734		       " based on configured SSID\n",
735		       sdata->name, cbss->bssid);
736
737		ieee80211_sta_join_ibss(sdata, bss);
738		ieee80211_rx_bss_put(local, bss);
739		return;
740	}
741
742#ifdef CONFIG_MAC80211_IBSS_DEBUG
743	printk(KERN_DEBUG "   did not try to join ibss\n");
744#endif /* CONFIG_MAC80211_IBSS_DEBUG */
745
746	/* Selected IBSS not found in current scan results - try to scan */
747	if (time_after(jiffies, ifibss->last_scan_completed +
748					IEEE80211_SCAN_INTERVAL)) {
749		printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
750		       "join\n", sdata->name);
751
752		ieee80211_request_internal_scan(sdata,
753				ifibss->ssid, ifibss->ssid_len,
754				ifibss->fixed_channel ? ifibss->channel : NULL);
755	} else {
756		int interval = IEEE80211_SCAN_INTERVAL;
757
758		if (time_after(jiffies, ifibss->ibss_join_req +
759			       IEEE80211_IBSS_JOIN_TIMEOUT)) {
760			if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
761				ieee80211_sta_create_ibss(sdata);
762				return;
763			}
764			printk(KERN_DEBUG "%s: IBSS not allowed on"
765			       " %d MHz\n", sdata->name,
766			       local->hw.conf.channel->center_freq);
767
768			/* No IBSS found - decrease scan interval and continue
769			 * scanning. */
770			interval = IEEE80211_SCAN_INTERVAL_SLOW;
771		}
772
773		mod_timer(&ifibss->timer,
774			  round_jiffies(jiffies + interval));
775	}
776}
777
778static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
779					struct sk_buff *req)
780{
781	struct ieee80211_mgmt *mgmt = (void *)req->data;
782	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
783	struct ieee80211_local *local = sdata->local;
784	int tx_last_beacon, len = req->len;
785	struct sk_buff *skb;
786	struct ieee80211_mgmt *resp;
787	struct sk_buff *presp;
788	u8 *pos, *end;
789
790	lockdep_assert_held(&ifibss->mtx);
791
792	presp = rcu_dereference_protected(ifibss->presp,
793					  lockdep_is_held(&ifibss->mtx));
794
795	if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
796	    len < 24 + 2 || !presp)
797		return;
798
799	tx_last_beacon = drv_tx_last_beacon(local);
800
801#ifdef CONFIG_MAC80211_IBSS_DEBUG
802	printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM"
803	       " (tx_last_beacon=%d)\n",
804	       sdata->name, mgmt->sa, mgmt->da,
805	       mgmt->bssid, tx_last_beacon);
806#endif /* CONFIG_MAC80211_IBSS_DEBUG */
807
808	if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da))
809		return;
810
811	if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 &&
812	    memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0)
813		return;
814
815	end = ((u8 *) mgmt) + len;
816	pos = mgmt->u.probe_req.variable;
817	if (pos[0] != WLAN_EID_SSID ||
818	    pos + 2 + pos[1] > end) {
819#ifdef CONFIG_MAC80211_IBSS_DEBUG
820		printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq "
821		       "from %pM\n",
822		       sdata->name, mgmt->sa);
823#endif
824		return;
825	}
826	if (pos[1] != 0 &&
827	    (pos[1] != ifibss->ssid_len ||
828	     memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
829		/* Ignore ProbeReq for foreign SSID */
830		return;
831	}
832
833	/* Reply with ProbeResp */
834	skb = skb_copy(presp, GFP_KERNEL);
835	if (!skb)
836		return;
837
838	resp = (struct ieee80211_mgmt *) skb->data;
839	memcpy(resp->da, mgmt->sa, ETH_ALEN);
840#ifdef CONFIG_MAC80211_IBSS_DEBUG
841	printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n",
842	       sdata->name, resp->da);
843#endif /* CONFIG_MAC80211_IBSS_DEBUG */
844	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
845	ieee80211_tx_skb(sdata, skb);
846}
847
848static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
849					 struct ieee80211_mgmt *mgmt,
850					 size_t len,
851					 struct ieee80211_rx_status *rx_status)
852{
853	size_t baselen;
854	struct ieee802_11_elems elems;
855
856	baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
857	if (baselen > len)
858		return;
859
860	ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
861				&elems);
862
863	ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
864}
865
866static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
867				     struct ieee80211_mgmt *mgmt,
868				     size_t len,
869				     struct ieee80211_rx_status *rx_status)
870{
871	size_t baselen;
872	struct ieee802_11_elems elems;
873
874	/* Process beacon from the current BSS */
875	baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
876	if (baselen > len)
877		return;
878
879	ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
880
881	ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
882}
883
884void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
885				   struct sk_buff *skb)
886{
887	struct ieee80211_rx_status *rx_status;
888	struct ieee80211_mgmt *mgmt;
889	u16 fc;
890
891	rx_status = IEEE80211_SKB_RXCB(skb);
892	mgmt = (struct ieee80211_mgmt *) skb->data;
893	fc = le16_to_cpu(mgmt->frame_control);
894
895	mutex_lock(&sdata->u.ibss.mtx);
896
897	if (!sdata->u.ibss.ssid_len)
898		goto mgmt_out; /* not ready to merge yet */
899
900	switch (fc & IEEE80211_FCTL_STYPE) {
901	case IEEE80211_STYPE_PROBE_REQ:
902		ieee80211_rx_mgmt_probe_req(sdata, skb);
903		break;
904	case IEEE80211_STYPE_PROBE_RESP:
905		ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
906					     rx_status);
907		break;
908	case IEEE80211_STYPE_BEACON:
909		ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
910					 rx_status);
911		break;
912	case IEEE80211_STYPE_AUTH:
913		ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
914		break;
915	}
916
917 mgmt_out:
918	mutex_unlock(&sdata->u.ibss.mtx);
919}
920
921void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
922{
923	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
924	struct sta_info *sta;
925
926	mutex_lock(&ifibss->mtx);
927
928	/*
929	 * Work could be scheduled after scan or similar
930	 * when we aren't even joined (or trying) with a
931	 * network.
932	 */
933	if (!ifibss->ssid_len)
934		goto out;
935
936	spin_lock_bh(&ifibss->incomplete_lock);
937	while (!list_empty(&ifibss->incomplete_stations)) {
938		sta = list_first_entry(&ifibss->incomplete_stations,
939				       struct sta_info, list);
940		list_del(&sta->list);
941		spin_unlock_bh(&ifibss->incomplete_lock);
942
943		ieee80211_ibss_finish_sta(sta);
944		rcu_read_unlock();
945		spin_lock_bh(&ifibss->incomplete_lock);
946	}
947	spin_unlock_bh(&ifibss->incomplete_lock);
948
949	switch (ifibss->state) {
950	case IEEE80211_IBSS_MLME_SEARCH:
951		ieee80211_sta_find_ibss(sdata);
952		break;
953	case IEEE80211_IBSS_MLME_JOINED:
954		ieee80211_sta_merge_ibss(sdata);
955		break;
956	default:
957		WARN_ON(1);
958		break;
959	}
960
961 out:
962	mutex_unlock(&ifibss->mtx);
963}
964
965static void ieee80211_ibss_timer(unsigned long data)
966{
967	struct ieee80211_sub_if_data *sdata =
968		(struct ieee80211_sub_if_data *) data;
969	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
970	struct ieee80211_local *local = sdata->local;
971
972	if (local->quiescing) {
973		ifibss->timer_running = true;
974		return;
975	}
976
977	ieee80211_queue_work(&local->hw, &sdata->work);
978}
979
980#ifdef CONFIG_PM
981void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata)
982{
983	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
984
985	if (del_timer_sync(&ifibss->timer))
986		ifibss->timer_running = true;
987}
988
989void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata)
990{
991	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
992
993	if (ifibss->timer_running) {
994		add_timer(&ifibss->timer);
995		ifibss->timer_running = false;
996	}
997}
998#endif
999
1000void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
1001{
1002	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1003
1004	setup_timer(&ifibss->timer, ieee80211_ibss_timer,
1005		    (unsigned long) sdata);
1006	mutex_init(&ifibss->mtx);
1007	INIT_LIST_HEAD(&ifibss->incomplete_stations);
1008	spin_lock_init(&ifibss->incomplete_lock);
1009}
1010
1011/* scan finished notification */
1012void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
1013{
1014	struct ieee80211_sub_if_data *sdata;
1015
1016	mutex_lock(&local->iflist_mtx);
1017	list_for_each_entry(sdata, &local->interfaces, list) {
1018		if (!ieee80211_sdata_running(sdata))
1019			continue;
1020		if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
1021			continue;
1022		sdata->u.ibss.last_scan_completed = jiffies;
1023		ieee80211_queue_work(&local->hw, &sdata->work);
1024	}
1025	mutex_unlock(&local->iflist_mtx);
1026}
1027
1028int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
1029			struct cfg80211_ibss_params *params)
1030{
1031	struct sk_buff *skb;
1032	u32 changed = 0;
1033
1034	skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
1035			    sizeof(struct ieee80211_hdr_3addr) +
1036			    12 /* struct ieee80211_mgmt.u.beacon */ +
1037			    2 + IEEE80211_MAX_SSID_LEN /* max SSID */ +
1038			    2 + 8 /* max Supported Rates */ +
1039			    3 /* max DS params */ +
1040			    4 /* IBSS params */ +
1041			    2 + (IEEE80211_MAX_SUPP_RATES - 8) +
1042			    2 + sizeof(struct ieee80211_ht_cap) +
1043			    2 + sizeof(struct ieee80211_ht_info) +
1044			    params->ie_len);
1045	if (!skb)
1046		return -ENOMEM;
1047
1048	mutex_lock(&sdata->u.ibss.mtx);
1049
1050	if (params->bssid) {
1051		memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
1052		sdata->u.ibss.fixed_bssid = true;
1053	} else
1054		sdata->u.ibss.fixed_bssid = false;
1055
1056	sdata->u.ibss.privacy = params->privacy;
1057	sdata->u.ibss.basic_rates = params->basic_rates;
1058	memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate,
1059	       sizeof(params->mcast_rate));
1060
1061	sdata->vif.bss_conf.beacon_int = params->beacon_interval;
1062
1063	sdata->u.ibss.channel = params->channel;
1064	sdata->u.ibss.channel_type = params->channel_type;
1065	sdata->u.ibss.fixed_channel = params->channel_fixed;
1066
1067	/* fix ourselves to that channel now already */
1068	if (params->channel_fixed) {
1069		sdata->local->oper_channel = params->channel;
1070		if (!ieee80211_set_channel_type(sdata->local, sdata,
1071					       params->channel_type)) {
1072			mutex_unlock(&sdata->u.ibss.mtx);
1073			kfree_skb(skb);
1074			return -EINVAL;
1075		}
1076	}
1077
1078	if (params->ie) {
1079		sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
1080					   GFP_KERNEL);
1081		if (sdata->u.ibss.ie)
1082			sdata->u.ibss.ie_len = params->ie_len;
1083	}
1084
1085	sdata->u.ibss.skb = skb;
1086	sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
1087	sdata->u.ibss.ibss_join_req = jiffies;
1088
1089	memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);
1090	sdata->u.ibss.ssid_len = params->ssid_len;
1091
1092	mutex_unlock(&sdata->u.ibss.mtx);
1093
1094	mutex_lock(&sdata->local->mtx);
1095	ieee80211_recalc_idle(sdata->local);
1096	mutex_unlock(&sdata->local->mtx);
1097
1098	/*
1099	 * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is
1100	 * reserved, but an HT STA shall protect HT transmissions as though
1101	 * the HT Protection field were set to non-HT mixed mode.
1102	 *
1103	 * In an IBSS, the RIFS Mode field of the HT Operation element is
1104	 * also reserved, but an HT STA shall operate as though this field
1105	 * were set to 1.
1106	 */
1107
1108	sdata->vif.bss_conf.ht_operation_mode |=
1109		  IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED
1110		| IEEE80211_HT_PARAM_RIFS_MODE;
1111
1112	changed |= BSS_CHANGED_HT;
1113	ieee80211_bss_info_change_notify(sdata, changed);
1114
1115	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
1116
1117	return 0;
1118}
1119
1120int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
1121{
1122	struct sk_buff *skb;
1123	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1124	struct ieee80211_local *local = sdata->local;
1125	struct cfg80211_bss *cbss;
1126	u16 capability;
1127	int active_ibss;
1128	struct sta_info *sta;
1129
1130	mutex_lock(&sdata->u.ibss.mtx);
1131
1132	sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
1133	memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
1134	sdata->u.ibss.ssid_len = 0;
1135
1136	active_ibss = ieee80211_sta_active_ibss(sdata);
1137
1138	if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) {
1139		capability = WLAN_CAPABILITY_IBSS;
1140
1141		if (ifibss->privacy)
1142			capability |= WLAN_CAPABILITY_PRIVACY;
1143
1144		cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->channel,
1145					ifibss->bssid, ifibss->ssid,
1146					ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
1147					WLAN_CAPABILITY_PRIVACY,
1148					capability);
1149
1150		if (cbss) {
1151			cfg80211_unlink_bss(local->hw.wiphy, cbss);
1152			cfg80211_put_bss(cbss);
1153		}
1154	}
1155
1156	sta_info_flush(sdata->local, sdata);
1157
1158	spin_lock_bh(&ifibss->incomplete_lock);
1159	while (!list_empty(&ifibss->incomplete_stations)) {
1160		sta = list_first_entry(&ifibss->incomplete_stations,
1161				       struct sta_info, list);
1162		list_del(&sta->list);
1163		spin_unlock_bh(&ifibss->incomplete_lock);
1164
1165		sta_info_free(local, sta);
1166		spin_lock_bh(&ifibss->incomplete_lock);
1167	}
1168	spin_unlock_bh(&ifibss->incomplete_lock);
1169
1170	netif_carrier_off(sdata->dev);
1171
1172	/* remove beacon */
1173	kfree(sdata->u.ibss.ie);
1174	skb = rcu_dereference_protected(sdata->u.ibss.presp,
1175					lockdep_is_held(&sdata->u.ibss.mtx));
1176	RCU_INIT_POINTER(sdata->u.ibss.presp, NULL);
1177	sdata->vif.bss_conf.ibss_joined = false;
1178	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
1179						BSS_CHANGED_IBSS);
1180	synchronize_rcu();
1181	kfree_skb(skb);
1182
1183	skb_queue_purge(&sdata->skb_queue);
1184
1185	del_timer_sync(&sdata->u.ibss.timer);
1186
1187	mutex_unlock(&sdata->u.ibss.mtx);
1188
1189	mutex_lock(&local->mtx);
1190	ieee80211_recalc_idle(sdata->local);
1191	mutex_unlock(&local->mtx);
1192
1193	return 0;
1194}
1195