ibss.c 30.7 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
/*
 * IBSS mode implementation
 * Copyright 2003-2008, Jouni Malinen <j@w1.fi>
 * Copyright 2004, Instant802 Networks, Inc.
 * Copyright 2005, Devicescape Software, Inc.
 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
 * Copyright 2009, Johannes Berg <johannes@sipsolutions.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/delay.h>
16
#include <linux/slab.h>
17 18 19 20 21 22 23 24
#include <linux/if_ether.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>
#include <net/mac80211.h>

#include "ieee80211_i.h"
25
#include "driver-ops.h"
26 27 28 29 30 31 32 33 34 35 36
#include "rate.h"

#define IEEE80211_SCAN_INTERVAL (2 * HZ)
#define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)

#define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
#define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)

#define IEEE80211_IBSS_MAX_STA_ENTRIES 128


37 38 39
static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
				      const u8 *bssid, const int beacon_int,
				      struct ieee80211_channel *chan,
40
				      const u32 basic_rates,
41 42
				      const u16 capability, u64 tsf,
				      bool creator)
43 44 45
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;
46
	int rates, i;
47 48 49
	struct ieee80211_mgmt *mgmt;
	u8 *pos;
	struct ieee80211_supported_band *sband;
Johannes Berg's avatar
Johannes Berg committed
50
	struct cfg80211_bss *bss;
51
	u32 bss_change;
52
	u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
53
	struct cfg80211_chan_def chandef;
54 55
	struct beacon_data *presp;
	int frame_len;
56

57
	sdata_assert_lock(sdata);
Johannes Berg's avatar
Johannes Berg committed
58

59
	/* Reset own TSF to allow time synchronization work. */
60
	drv_reset_tsf(local, sdata);
61

62
	if (!ether_addr_equal(ifibss->bssid, bssid))
63
		sta_info_flush(sdata);
64

65 66 67
	/* if merging, indicate to driver that we leave the old IBSS */
	if (sdata->vif.bss_conf.ibss_joined) {
		sdata->vif.bss_conf.ibss_joined = false;
68
		sdata->vif.bss_conf.ibss_creator = false;
69
		sdata->vif.bss_conf.enable_beacon = false;
70
		netif_carrier_off(sdata->dev);
71 72 73
		ieee80211_bss_info_change_notify(sdata,
						 BSS_CHANGED_IBSS |
						 BSS_CHANGED_BEACON_ENABLED);
74 75
	}

76
	presp = rcu_dereference_protected(ifibss->presp,
77
					  lockdep_is_held(&sdata->wdev.mtx));
78 79 80
	rcu_assign_pointer(ifibss->presp, NULL);
	if (presp)
		kfree_rcu(presp, rcu_head);
81

82
	sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
83

84
	chandef = ifibss->chandef;
85 86 87 88
	if (!cfg80211_reg_can_beacon(local->hw.wiphy, &chandef)) {
		chandef.width = NL80211_CHAN_WIDTH_20;
		chandef.center_freq1 = chan->center_freq;
	}
Johannes Berg's avatar
Johannes Berg committed
89 90

	ieee80211_vif_release_channel(sdata);
91
	if (ieee80211_vif_use_channel(sdata, &chandef,
Johannes Berg's avatar
Johannes Berg committed
92 93 94 95 96
				      ifibss->fixed_channel ?
					IEEE80211_CHANCTX_SHARED :
					IEEE80211_CHANCTX_EXCLUSIVE)) {
		sdata_info(sdata, "Failed to join IBSS, no channel context\n");
		return;
97
	}
Johannes Berg's avatar
Johannes Berg committed
98 99

	memcpy(ifibss->bssid, bssid, ETH_ALEN);
100

101
	sband = local->hw.wiphy->bands[chan->band];
102 103

	/* Build IBSS probe response */
104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120
	frame_len = sizeof(struct ieee80211_hdr_3addr) +
		    12 /* struct ieee80211_mgmt.u.beacon */ +
		    2 + IEEE80211_MAX_SSID_LEN /* max SSID */ +
		    2 + 8 /* max Supported Rates */ +
		    3 /* max DS params */ +
		    4 /* IBSS params */ +
		    2 + (IEEE80211_MAX_SUPP_RATES - 8) +
		    2 + sizeof(struct ieee80211_ht_cap) +
		    2 + sizeof(struct ieee80211_ht_operation) +
		    ifibss->ie_len;
	presp = kzalloc(sizeof(*presp) + frame_len, GFP_KERNEL);
	if (!presp)
		return;

	presp->head = (void *)(presp + 1);

	mgmt = (void *) presp->head;
121 122
	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
					  IEEE80211_STYPE_PROBE_RESP);
123
	eth_broadcast_addr(mgmt->da);
124
	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
125
	memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
126
	mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
127
	mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
128 129
	mgmt->u.beacon.capab_info = cpu_to_le16(capability);

130 131
	pos = (u8 *)mgmt + offsetof(struct ieee80211_mgmt, u.beacon.variable);

132 133 134
	*pos++ = WLAN_EID_SSID;
	*pos++ = ifibss->ssid_len;
	memcpy(pos, ifibss->ssid, ifibss->ssid_len);
135
	pos += ifibss->ssid_len;
136

137
	rates = min_t(int, 8, sband->n_bitrates);
138 139
	*pos++ = WLAN_EID_SUPP_RATES;
	*pos++ = rates;
140 141 142 143 144 145 146
	for (i = 0; i < rates; i++) {
		int rate = sband->bitrates[i].bitrate;
		u8 basic = 0;
		if (basic_rates & BIT(i))
			basic = 0x80;
		*pos++ = basic | (u8) (rate / 5);
	}
147 148 149 150

	if (sband->band == IEEE80211_BAND_2GHZ) {
		*pos++ = WLAN_EID_DS_PARAMS;
		*pos++ = 1;
151
		*pos++ = ieee80211_frequency_to_channel(chan->center_freq);
152 153 154 155 156 157 158 159
	}

	*pos++ = WLAN_EID_IBSS_PARAMS;
	*pos++ = 2;
	/* FIX: set ATIM window based on scan results */
	*pos++ = 0;
	*pos++ = 0;

160
	if (sband->n_bitrates > 8) {
161
		*pos++ = WLAN_EID_EXT_SUPP_RATES;
162 163 164 165 166 167 168 169
		*pos++ = sband->n_bitrates - 8;
		for (i = 8; i < sband->n_bitrates; i++) {
			int rate = sband->bitrates[i].bitrate;
			u8 basic = 0;
			if (basic_rates & BIT(i))
				basic = 0x80;
			*pos++ = basic | (u8) (rate / 5);
		}
170 171
	}

172 173 174 175
	if (ifibss->ie_len) {
		memcpy(pos, ifibss->ie, ifibss->ie_len);
		pos += ifibss->ie_len;
	}
176

177
	/* add HT capability and information IEs */
178
	if (chandef.width != NL80211_CHAN_WIDTH_20_NOHT &&
179 180
	    chandef.width != NL80211_CHAN_WIDTH_5 &&
	    chandef.width != NL80211_CHAN_WIDTH_10 &&
181
	    sband->ht_cap.ht_supported) {
182 183
		pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap,
						sband->ht_cap.cap);
184 185 186 187 188
		/*
		 * Note: According to 802.11n-2009 9.13.3.1, HT Protection
		 * field and RIFS Mode are reserved in IBSS mode, therefore
		 * keep them at 0
		 */
189
		pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap,
190
						 &chandef, 0);
191 192
	}

193
	if (local->hw.queues >= IEEE80211_NUM_ACS) {
194 195 196 197 198 199 200 201 202 203 204
		*pos++ = WLAN_EID_VENDOR_SPECIFIC;
		*pos++ = 7; /* len */
		*pos++ = 0x00; /* Microsoft OUI 00:50:F2 */
		*pos++ = 0x50;
		*pos++ = 0xf2;
		*pos++ = 2; /* WME */
		*pos++ = 0; /* WME info */
		*pos++ = 1; /* WME ver */
		*pos++ = 0; /* U-APSD no in use */
	}

205 206 207 208 209
	presp->head_len = pos - presp->head;
	if (WARN_ON(presp->head_len > frame_len))
		return;

	rcu_assign_pointer(ifibss->presp, presp);
210

211
	sdata->vif.bss_conf.enable_beacon = true;
212
	sdata->vif.bss_conf.beacon_int = beacon_int;
213
	sdata->vif.bss_conf.basic_rates = basic_rates;
214 215
	sdata->vif.bss_conf.ssid_len = ifibss->ssid_len;
	memcpy(sdata->vif.bss_conf.ssid, ifibss->ssid, ifibss->ssid_len);
216 217 218 219 220
	bss_change = BSS_CHANGED_BEACON_INT;
	bss_change |= ieee80211_reset_erp_info(sdata);
	bss_change |= BSS_CHANGED_BSSID;
	bss_change |= BSS_CHANGED_BEACON;
	bss_change |= BSS_CHANGED_BEACON_ENABLED;
221
	bss_change |= BSS_CHANGED_BASIC_RATES;
222
	bss_change |= BSS_CHANGED_HT;
223
	bss_change |= BSS_CHANGED_IBSS;
224
	bss_change |= BSS_CHANGED_SSID;
225 226 227 228 229 230 231 232 233 234 235 236 237 238

	/*
	 * In 5 GHz/802.11a, we can always use short slot time.
	 * (IEEE 802.11-2012 18.3.8.7)
	 *
	 * In 2.4GHz, we must always use long slots in IBSS for compatibility
	 * reasons.
	 * (IEEE 802.11-2012 19.4.5)
	 *
	 * HT follows these specifications (IEEE 802.11-2012 20.3.18)
	 */
	sdata->vif.bss_conf.use_short_slot = chan->band == IEEE80211_BAND_5GHZ;
	bss_change |= BSS_CHANGED_ERP_SLOT;

239
	sdata->vif.bss_conf.ibss_joined = true;
240
	sdata->vif.bss_conf.ibss_creator = creator;
241
	ieee80211_bss_info_change_notify(sdata, bss_change);
242

243
	ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates);
244 245

	ifibss->state = IEEE80211_IBSS_MLME_JOINED;
246 247
	mod_timer(&ifibss->timer,
		  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
248

249
	bss = cfg80211_inform_bss_frame(local->hw.wiphy, chan,
250
					mgmt, presp->head_len, 0, GFP_KERNEL);
251
	cfg80211_put_bss(local->hw.wiphy, bss);
252
	netif_carrier_on(sdata->dev);
253
	cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
254 255
}

256 257
static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
				    struct ieee80211_bss *bss)
258
{
259 260
	struct cfg80211_bss *cbss =
		container_of((void *)bss, struct cfg80211_bss, priv);
261 262 263
	struct ieee80211_supported_band *sband;
	u32 basic_rates;
	int i, j;
264
	u16 beacon_int = cbss->beacon_interval;
Johannes Berg's avatar
Johannes Berg committed
265 266
	const struct cfg80211_bss_ies *ies;
	u64 tsf;
267

268
	sdata_assert_lock(sdata);
Johannes Berg's avatar
Johannes Berg committed
269

270 271 272
	if (beacon_int < 10)
		beacon_int = 10;

273
	sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289

	basic_rates = 0;

	for (i = 0; i < bss->supp_rates_len; i++) {
		int rate = (bss->supp_rates[i] & 0x7f) * 5;
		bool is_basic = !!(bss->supp_rates[i] & 0x80);

		for (j = 0; j < sband->n_bitrates; j++) {
			if (sband->bitrates[j].bitrate == rate) {
				if (is_basic)
					basic_rates |= BIT(j);
				break;
			}
		}
	}

Johannes Berg's avatar
Johannes Berg committed
290 291 292 293 294
	rcu_read_lock();
	ies = rcu_dereference(cbss->ies);
	tsf = ies->tsf;
	rcu_read_unlock();

295
	__ieee80211_sta_join_ibss(sdata, cbss->bssid,
296
				  beacon_int,
297
				  cbss->channel,
298
				  basic_rates,
299
				  cbss->capability,
Johannes Berg's avatar
Johannes Berg committed
300
				  tsf, false);
301 302
}

303
static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta)
304 305 306 307 308 309 310
	__acquires(RCU)
{
	struct ieee80211_sub_if_data *sdata = sta->sdata;
	u8 addr[ETH_ALEN];

	memcpy(addr, sta->sta.addr, ETH_ALEN);

Johannes Berg's avatar
Johannes Berg committed
311
	ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr);
312

313 314
	sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
	sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
315 316 317 318
	/* authorize the station only if the network is not RSN protected. If
	 * not wait for the userspace to authorize it */
	if (!sta->sdata->u.ibss.control_port)
		sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
319 320 321 322 323 324 325 326 327 328

	rate_control_rate_init(sta);

	/* If it fails, maybe we raced another insertion? */
	if (sta_info_insert_rcu(sta))
		return sta_info_get(sdata, addr);
	return sta;
}

static struct sta_info *
329 330
ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata, const u8 *bssid,
		       const u8 *addr, u32 supp_rates)
331 332 333 334 335
	__acquires(RCU)
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;
	struct sta_info *sta;
Johannes Berg's avatar
Johannes Berg committed
336
	struct ieee80211_chanctx_conf *chanctx_conf;
337
	struct ieee80211_supported_band *sband;
Johannes Berg's avatar
Johannes Berg committed
338
	int band;
339 340 341 342 343 344

	/*
	 * XXX: Consider removing the least recently used entry and
	 * 	allow new one to be added.
	 */
	if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
Johannes Berg's avatar
Johannes Berg committed
345
		net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
346
				    sdata->name, addr);
347 348 349 350 351 352 353 354 355
		rcu_read_lock();
		return NULL;
	}

	if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) {
		rcu_read_lock();
		return NULL;
	}

356
	if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) {
357 358 359 360
		rcu_read_lock();
		return NULL;
	}

Johannes Berg's avatar
Johannes Berg committed
361 362 363 364
	rcu_read_lock();
	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
	if (WARN_ON_ONCE(!chanctx_conf))
		return NULL;
365
	band = chanctx_conf->def.chan->band;
Johannes Berg's avatar
Johannes Berg committed
366 367
	rcu_read_unlock();

368 369 370 371 372 373 374 375 376
	sta = sta_info_alloc(sdata, addr, GFP_KERNEL);
	if (!sta) {
		rcu_read_lock();
		return NULL;
	}

	sta->last_rx = jiffies;

	/* make sure mandatory rates are always added */
377
	sband = local->hw.wiphy->bands[band];
378
	sta->sta.supp_rates[band] = supp_rates |
379
			ieee80211_mandatory_rates(sband);
380

381
	return ieee80211_ibss_finish_sta(sta);
382 383
}

384 385 386 387 388 389 390 391 392 393 394 395 396 397
static void ieee80211_rx_mgmt_deauth_ibss(struct ieee80211_sub_if_data *sdata,
					  struct ieee80211_mgmt *mgmt,
					  size_t len)
{
	u16 reason = le16_to_cpu(mgmt->u.deauth.reason_code);

	if (len < IEEE80211_DEAUTH_FRAME_LEN)
		return;

	ibss_dbg(sdata, "RX DeAuth SA=%pM DA=%pM BSSID=%pM (reason: %d)\n",
		 mgmt->sa, mgmt->da, mgmt->bssid, reason);
	sta_info_destroy_addr(sdata, mgmt->sa);
}

398 399 400 401 402 403
static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
					struct ieee80211_mgmt *mgmt,
					size_t len)
{
	u16 auth_alg, auth_transaction;

404
	sdata_assert_lock(sdata);
405 406 407 408 409 410 411

	if (len < 24 + 6)
		return;

	auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
	auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);

Johannes Berg's avatar
Johannes Berg committed
412 413 414
	ibss_dbg(sdata,
		 "RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n",
		 mgmt->sa, mgmt->da, mgmt->bssid, auth_transaction);
415 416 417 418

	if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1)
		return;

419 420 421 422 423 424
	/*
	 * IEEE 802.11 standard does not require authentication in IBSS
	 * networks and most implementations do not seem to use it.
	 * However, try to reply to authentication attempts if someone
	 * has actually implemented this.
	 */
425
	ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, 0, NULL, 0,
426
			    mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0, 0);
427 428
}

429
static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
430
				  struct ieee80211_mgmt *mgmt, size_t len,
431
				  struct ieee80211_rx_status *rx_status,
432
				  struct ieee802_11_elems *elems)
433 434 435
{
	struct ieee80211_local *local = sdata->local;
	int freq;
436
	struct cfg80211_bss *cbss;
437 438 439 440 441 442
	struct ieee80211_bss *bss;
	struct sta_info *sta;
	struct ieee80211_channel *channel;
	u64 beacon_timestamp, rx_timestamp;
	u32 supp_rates = 0;
	enum ieee80211_band band = rx_status->band;
443 444
	struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
	bool rates_updated = false;
445

446
	if (elems->ds_params)
447 448
		freq = ieee80211_channel_to_frequency(elems->ds_params[0],
						      band);
449 450 451 452 453 454 455 456
	else
		freq = rx_status->freq;

	channel = ieee80211_get_channel(local->hw.wiphy, freq);

	if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
		return;

457
	if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
458
	    ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid)) {
459 460

		rcu_read_lock();
461
		sta = sta_info_get(sdata, mgmt->sa);
462

463 464
		if (elems->supp_rates) {
			supp_rates = ieee80211_sta_get_rates(local, elems,
465
							     band, NULL);
466 467 468 469 470 471
			if (sta) {
				u32 prev_rates;

				prev_rates = sta->sta.supp_rates[band];
				/* make sure mandatory rates are always added */
				sta->sta.supp_rates[band] = supp_rates |
472
					ieee80211_mandatory_rates(sband);
473

474
				if (sta->sta.supp_rates[band] != prev_rates) {
Johannes Berg's avatar
Johannes Berg committed
475 476 477 478
					ibss_dbg(sdata,
						 "updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n",
						 sta->sta.addr, prev_rates,
						 sta->sta.supp_rates[band]);
479
					rates_updated = true;
480
				}
481 482
			} else {
				rcu_read_unlock();
483
				sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
484
						mgmt->sa, supp_rates);
485
			}
486
		}
487 488

		if (sta && elems->wmm_info)
489
			set_sta_flag(sta, WLAN_STA_WME);
490

491
		if (sta && elems->ht_operation && elems->ht_cap_elem &&
492 493 494
		    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_20_NOHT &&
		    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_5 &&
		    sdata->u.ibss.chandef.width != NL80211_CHAN_WIDTH_10) {
495
			/* we both use HT */
496
			struct ieee80211_ht_cap htcap_ie;
497 498 499 500 501
			struct cfg80211_chan_def chandef;

			ieee80211_ht_oper_to_chandef(channel,
						     elems->ht_operation,
						     &chandef);
502

503
			memcpy(&htcap_ie, elems->ht_cap_elem, sizeof(htcap_ie));
504 505 506 507 508

			/*
			 * fall back to HT20 if we don't use or use
			 * the other extension channel
			 */
509 510
			if (chandef.center_freq1 !=
			    sdata->u.ibss.chandef.center_freq1)
511 512 513 514 515
				htcap_ie.cap_info &=
					cpu_to_le16(~IEEE80211_HT_CAP_SUP_WIDTH_20_40);

			rates_updated |= ieee80211_ht_cap_ie_to_sta_ht_cap(
						sdata, sband, &htcap_ie, sta);
516 517
		}

518 519 520
		if (sta && rates_updated) {
			drv_sta_rc_update(local, sdata, &sta->sta,
					  IEEE80211_RC_SUPP_RATES_CHANGED);
521
			rate_control_rate_init(sta);
522
		}
523

524
		rcu_read_unlock();
525 526 527
	}

	bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
528
					channel);
529 530 531
	if (!bss)
		return;

532 533
	cbss = container_of((void *)bss, struct cfg80211_bss, priv);

Johannes Berg's avatar
Johannes Berg committed
534 535
	/* same for beacon and probe response */
	beacon_timestamp = le64_to_cpu(mgmt->u.beacon.timestamp);
536 537 538 539

	/* check if we need to merge IBSS */

	/* we use a fixed BSSID */
540
	if (sdata->u.ibss.fixed_bssid)
541 542 543
		goto put_bss;

	/* not an IBSS */
544
	if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
545 546 547
		goto put_bss;

	/* different channel */
Johannes Berg's avatar
Johannes Berg committed
548
	if (sdata->u.ibss.fixed_channel &&
549
	    sdata->u.ibss.chandef.chan != cbss->channel)
550 551 552 553 554 555 556 557
		goto put_bss;

	/* different SSID */
	if (elems->ssid_len != sdata->u.ibss.ssid_len ||
	    memcmp(elems->ssid, sdata->u.ibss.ssid,
				sdata->u.ibss.ssid_len))
		goto put_bss;

558
	/* same BSSID */
559
	if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid))
560 561
		goto put_bss;

562 563 564 565 566
	if (ieee80211_have_rx_timestamp(rx_status)) {
		/* time when timestamp field was received */
		rx_timestamp =
			ieee80211_calculate_rx_timestamp(local, rx_status,
							 len + FCS_LEN, 24);
567 568 569 570 571
	} else {
		/*
		 * second best option: get current TSF
		 * (will return -1 if not supported)
		 */
572
		rx_timestamp = drv_get_tsf(local, sdata);
573
	}
574

Johannes Berg's avatar
Johannes Berg committed
575 576 577 578 579 580 581
	ibss_dbg(sdata,
		 "RX beacon SA=%pM BSSID=%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
		 mgmt->sa, mgmt->bssid,
		 (unsigned long long)rx_timestamp,
		 (unsigned long long)beacon_timestamp,
		 (unsigned long long)(rx_timestamp - beacon_timestamp),
		 jiffies);
582 583

	if (beacon_timestamp > rx_timestamp) {
Johannes Berg's avatar
Johannes Berg committed
584 585 586
		ibss_dbg(sdata,
			 "beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n",
			 mgmt->bssid);
587
		ieee80211_sta_join_ibss(sdata, bss);
588
		supp_rates = ieee80211_sta_get_rates(local, elems, band, NULL);
589
		ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
590
				       supp_rates);
591
		rcu_read_unlock();
592 593 594 595 596 597
	}

 put_bss:
	ieee80211_rx_bss_put(local, bss);
}

598 599 600
void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata,
			      const u8 *bssid, const u8 *addr,
			      u32 supp_rates)
601
{
602
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
603 604
	struct ieee80211_local *local = sdata->local;
	struct sta_info *sta;
Johannes Berg's avatar
Johannes Berg committed
605
	struct ieee80211_chanctx_conf *chanctx_conf;
606
	struct ieee80211_supported_band *sband;
Johannes Berg's avatar
Johannes Berg committed
607
	int band;
608

609 610 611 612
	/*
	 * XXX: Consider removing the least recently used entry and
	 * 	allow new one to be added.
	 */
613
	if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
Johannes Berg's avatar
Johannes Berg committed
614
		net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
615
				    sdata->name, addr);
616
		return;
617 618
	}

619
	if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
620
		return;
621

622
	if (!ether_addr_equal(bssid, sdata->u.ibss.bssid))
623
		return;
624

Johannes Berg's avatar
Johannes Berg committed
625 626 627 628 629 630
	rcu_read_lock();
	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
	if (WARN_ON_ONCE(!chanctx_conf)) {
		rcu_read_unlock();
		return;
	}
631
	band = chanctx_conf->def.chan->band;
Johannes Berg's avatar
Johannes Berg committed
632 633
	rcu_read_unlock();

634
	sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
635
	if (!sta)
636
		return;
637

638
	sta->last_rx = jiffies;
639

640
	/* make sure mandatory rates are always added */
641
	sband = local->hw.wiphy->bands[band];
642
	sta->sta.supp_rates[band] = supp_rates |
643
			ieee80211_mandatory_rates(sband);
644

645 646 647 648
	spin_lock(&ifibss->incomplete_lock);
	list_add(&sta->list, &ifibss->incomplete_stations);
	spin_unlock(&ifibss->incomplete_lock);
	ieee80211_queue_work(&local->hw, &sdata->work);
649 650 651 652 653 654 655 656
}

static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_local *local = sdata->local;
	int active = 0;
	struct sta_info *sta;

657
	sdata_assert_lock(sdata);
Johannes Berg's avatar
Johannes Berg committed
658

659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674
	rcu_read_lock();

	list_for_each_entry_rcu(sta, &local->sta_list, list) {
		if (sta->sdata == sdata &&
		    time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
			       jiffies)) {
			active++;
			break;
		}
	}

	rcu_read_unlock();

	return active;
}

675 676 677
/*
 * This function is called with state == IEEE80211_IBSS_MLME_JOINED
 */
678 679 680 681 682

static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;

683
	sdata_assert_lock(sdata);
Johannes Berg's avatar
Johannes Berg committed
684

685 686
	mod_timer(&ifibss->timer,
		  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
687 688

	ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
689

Sujith's avatar
Sujith committed
690 691 692 693
	if (time_before(jiffies, ifibss->last_scan_completed +
		       IEEE80211_IBSS_MERGE_INTERVAL))
		return;

694 695 696
	if (ieee80211_sta_active_ibss(sdata))
		return;

697
	if (ifibss->fixed_channel)
698 699
		return;

Johannes Berg's avatar
Johannes Berg committed
700 701
	sdata_info(sdata,
		   "No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n");
702

703 704
	ieee80211_request_ibss_scan(sdata, ifibss->ssid, ifibss->ssid_len,
				    NULL);
705 706
}

707
static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
708 709 710 711 712 713
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	u8 bssid[ETH_ALEN];
	u16 capability;
	int i;

714
	sdata_assert_lock(sdata);
Johannes Berg's avatar
Johannes Berg committed
715

716
	if (ifibss->fixed_bssid) {
717 718 719 720 721 722 723
		memcpy(bssid, ifibss->bssid, ETH_ALEN);
	} else {
		/* Generate random, not broadcast, locally administered BSSID. Mix in
		 * own MAC address to make sure that devices that do not have proper
		 * random number generator get different BSSID. */
		get_random_bytes(bssid, ETH_ALEN);
		for (i = 0; i < ETH_ALEN; i++)
724
			bssid[i] ^= sdata->vif.addr[i];
725 726 727 728
		bssid[0] &= ~0x01;
		bssid[0] |= 0x02;
	}

Johannes Berg's avatar
Johannes Berg committed
729
	sdata_info(sdata, "Creating new IBSS network, BSSID %pM\n", bssid);
730 731 732

	capability = WLAN_CAPABILITY_IBSS;

Johannes Berg's avatar
Johannes Berg committed
733
	if (ifibss->privacy)
734 735 736 737
		capability |= WLAN_CAPABILITY_PRIVACY;
	else
		sdata->drop_unencrypted = 0;

738
	__ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
739
				  ifibss->chandef.chan, ifibss->basic_rates,
740
				  capability, 0, true);
741 742
}

743 744 745 746
/*
 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
 */

747
static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
748 749 750
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;
751
	struct cfg80211_bss *cbss;
752
	struct ieee80211_channel *chan = NULL;
753 754
	const u8 *bssid = NULL;
	int active_ibss;
755
	u16 capability;
756

757
	sdata_assert_lock(sdata);
Johannes Berg's avatar
Johannes Berg committed
758

759
	active_ibss = ieee80211_sta_active_ibss(sdata);
Johannes Berg's avatar
Johannes Berg committed
760
	ibss_dbg(sdata, "sta_find_ibss (active_ibss=%d)\n", active_ibss);
761 762

	if (active_ibss)
763
		return;
764

765
	capability = WLAN_CAPABILITY_IBSS;
Johannes Berg's avatar
Johannes Berg committed
766
	if (ifibss->privacy)
767
		capability |= WLAN_CAPABILITY_PRIVACY;
768 769 770
	if (ifibss->fixed_bssid)
		bssid = ifibss->bssid;
	if (ifibss->fixed_channel)
771
		chan = ifibss->chandef.chan;
772
	if (!is_zero_ether_addr(ifibss->bssid))
773
		bssid = ifibss->bssid;
774 775 776 777 778 779 780
	cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
				ifibss->ssid, ifibss->ssid_len,
				WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
				capability);

	if (cbss) {
		struct ieee80211_bss *bss;
781

782
		bss = (void *)cbss->priv;
Johannes Berg's avatar
Johannes Berg committed
783 784 785 786 787 788
		ibss_dbg(sdata,
			 "sta_find_ibss: selected %pM current %pM\n",
			 cbss->bssid, ifibss->bssid);
		sdata_info(sdata,
			   "Selected IBSS BSSID %pM based on configured SSID\n",
			   cbss->bssid);
789

790
		ieee80211_sta_join_ibss(sdata, bss);
791
		ieee80211_rx_bss_put(local, bss);
792
		return;
Reinette Chatre's avatar
Reinette Chatre committed
793
	}
794

Johannes Berg's avatar
Johannes Berg committed
795
	ibss_dbg(sdata, "sta_find_ibss: did not try to join ibss\n");
796 797

	/* Selected IBSS not found in current scan results - try to scan */
798
	if (time_after(jiffies, ifibss->last_scan_completed +
799
					IEEE80211_SCAN_INTERVAL)) {
Johannes Berg's avatar
Johannes Berg committed
800
		sdata_info(sdata, "Trigger new scan to find an IBSS to join\n");
801

802 803
		ieee80211_request_ibss_scan(sdata, ifibss->ssid,
					    ifibss->ssid_len, chan);
804
	} else {
805 806 807
		int interval = IEEE80211_SCAN_INTERVAL;

		if (time_after(jiffies, ifibss->ibss_join_req +
Johannes Berg's avatar
Johannes Berg committed
808 809
			       IEEE80211_IBSS_JOIN_TIMEOUT))
			ieee80211_sta_create_ibss(sdata);
810

811 812
		mod_timer(&ifibss->timer,
			  round_jiffies(jiffies + interval));
813 814 815 816
	}
}

static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
817
					struct sk_buff *req)
818
{
819
	struct ieee80211_mgmt *mgmt = (void *)req->data;
820 821
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;
822
	int tx_last_beacon, len = req->len;
823
	struct sk_buff *skb;
824
	struct beacon_data *presp;
825 826
	u8 *pos, *end;

827
	sdata_assert_lock(sdata);
Johannes Berg's avatar
Johannes Berg committed
828

829
	presp = rcu_dereference_protected(ifibss->presp,
830
					  lockdep_is_held(&sdata->wdev.mtx));
831

832
	if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
833
	    len < 24 + 2 || !presp)
834 835
		return;

836
	tx_last_beacon = drv_tx_last_beacon(local);
837

Johannes Berg's avatar
Johannes Berg committed
838 839 840
	ibss_dbg(sdata,
		 "RX ProbeReq SA=%pM DA=%pM BSSID=%pM (tx_last_beacon=%d)\n",
		 mgmt->sa, mgmt->da, mgmt->bssid, tx_last_beacon);
841

842
	if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da))
843 844
		return;

845
	if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) &&
846
	    !is_broadcast_ether_addr(mgmt->bssid))
847 848 849 850 851 852
		return;

	end = ((u8 *) mgmt) + len;
	pos = mgmt->u.probe_req.variable;
	if (pos[0] != WLAN_EID_SSID ||
	    pos + 2 + pos[1] > end) {
Johannes Berg's avatar
Johannes Berg committed
853 854
		ibss_dbg(sdata, "Invalid SSID IE in ProbeReq from %pM\n",
			 mgmt->sa);
855 856 857 858
		return;
	}
	if (pos[1] != 0 &&
	    (pos[1] != ifibss->ssid_len ||
859
	     memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
860 861 862 863 864
		/* Ignore ProbeReq for foreign SSID */
		return;
	}

	/* Reply with ProbeResp */
865
	skb = dev_alloc_skb(local->tx_headroom + presp->head_len);
866 867 868
	if (!skb)
		return;

869 870 871 872 873
	skb_reserve(skb, local->tx_headroom);
	memcpy(skb_put(skb, presp->head_len), presp->head, presp->head_len);

	memcpy(((struct ieee80211_mgmt *) skb->data)->da, mgmt->sa, ETH_ALEN);
	ibss_dbg(sdata, "Sending ProbeResp to %pM\n", mgmt->sa);
874 875
	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
	ieee80211_tx_skb(sdata, skb);
876 877
}

878 879 880 881
static
void ieee80211_rx_mgmt_probe_beacon(struct ieee80211_sub_if_data *sdata,
				    struct ieee80211_mgmt *mgmt, size_t len,
				    struct ieee80211_rx_status *rx_status)
882 883 884 885
{
	size_t baselen;
	struct ieee802_11_elems elems;

886 887 888 889