ibss.c 31.8 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

Johannes Berg's avatar
Johannes Berg committed
57 58
	lockdep_assert_held(&ifibss->mtx);

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 77 78 79 80
	presp = rcu_dereference_protected(ifibss->presp,
					  lockdep_is_held(&ifibss->mtx));
	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 85 86 87 88
	cfg80211_chandef_create(&chandef, chan, ifibss->channel_type);
	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
	    sband->ht_cap.ht_supported) {
180 181
		pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap,
						sband->ht_cap.cap);
182 183 184 185 186
		/*
		 * 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
		 */
187
		pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap,
188
						 &chandef, 0);
189 190
	}

191
	if (local->hw.queues >= IEEE80211_NUM_ACS) {
192 193 194 195 196 197 198 199 200 201 202
		*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 */
	}

203 204 205 206 207
	presp->head_len = pos - presp->head;
	if (WARN_ON(presp->head_len > frame_len))
		return;

	rcu_assign_pointer(ifibss->presp, presp);
208

209
	sdata->vif.bss_conf.enable_beacon = true;
210
	sdata->vif.bss_conf.beacon_int = beacon_int;
211
	sdata->vif.bss_conf.basic_rates = basic_rates;
212 213
	sdata->vif.bss_conf.ssid_len = ifibss->ssid_len;
	memcpy(sdata->vif.bss_conf.ssid, ifibss->ssid, ifibss->ssid_len);
214 215 216 217 218
	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;
219
	bss_change |= BSS_CHANGED_BASIC_RATES;
220
	bss_change |= BSS_CHANGED_HT;
221
	bss_change |= BSS_CHANGED_IBSS;
222
	bss_change |= BSS_CHANGED_SSID;
223 224 225 226 227 228 229 230 231 232 233 234 235 236

	/*
	 * 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;

237
	sdata->vif.bss_conf.ibss_joined = true;
238
	sdata->vif.bss_conf.ibss_creator = creator;
239
	ieee80211_bss_info_change_notify(sdata, bss_change);
240

241
	ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates);
242 243

	ifibss->state = IEEE80211_IBSS_MLME_JOINED;
244 245
	mod_timer(&ifibss->timer,
		  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
246

247
	bss = cfg80211_inform_bss_frame(local->hw.wiphy, chan,
248
					mgmt, presp->head_len, 0, GFP_KERNEL);
249
	cfg80211_put_bss(local->hw.wiphy, bss);
250
	netif_carrier_on(sdata->dev);
251
	cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
252 253
}

254 255
static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
				    struct ieee80211_bss *bss)
256
{
257 258
	struct cfg80211_bss *cbss =
		container_of((void *)bss, struct cfg80211_bss, priv);
259 260 261
	struct ieee80211_supported_band *sband;
	u32 basic_rates;
	int i, j;
262
	u16 beacon_int = cbss->beacon_interval;
Johannes Berg's avatar
Johannes Berg committed
263 264
	const struct cfg80211_bss_ies *ies;
	u64 tsf;
265

Johannes Berg's avatar
Johannes Berg committed
266 267
	lockdep_assert_held(&sdata->u.ibss.mtx);

268 269 270
	if (beacon_int < 10)
		beacon_int = 10;

271
	sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287

	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
288 289 290 291 292
	rcu_read_lock();
	ies = rcu_dereference(cbss->ies);
	tsf = ies->tsf;
	rcu_read_unlock();

293
	__ieee80211_sta_join_ibss(sdata, cbss->bssid,
294
				  beacon_int,
295
				  cbss->channel,
296
				  basic_rates,
297
				  cbss->capability,
Johannes Berg's avatar
Johannes Berg committed
298
				  tsf, false);
299 300
}

301 302
static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta,
						  bool auth)
303 304 305 306 307 308 309
	__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
310
	ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr);
311

312 313
	sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
	sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
314 315 316 317
	/* 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);
318 319 320 321 322 323

	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);
324
	if (auth && !sdata->u.ibss.auth_frame_registrations) {
Johannes Berg's avatar
Johannes Berg committed
325 326
		ibss_dbg(sdata,
			 "TX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=1)\n",
327
			 sdata->vif.addr, addr, sdata->u.ibss.bssid);
328
		ieee80211_send_auth(sdata, 1, WLAN_AUTH_OPEN, 0, NULL, 0,
329
				    addr, sdata->u.ibss.bssid, NULL, 0, 0, 0);
330
	}
331 332 333 334 335 336
	return sta;
}

static struct sta_info *
ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
		       const u8 *bssid, const u8 *addr,
337
		       u32 supp_rates, bool auth)
338 339 340 341 342
	__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
343
	struct ieee80211_chanctx_conf *chanctx_conf;
344
	struct ieee80211_supported_band *sband;
Johannes Berg's avatar
Johannes Berg committed
345
	int band;
346 347 348 349 350 351

	/*
	 * 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
352
		net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
353
				    sdata->name, addr);
354 355 356 357 358 359 360 361 362
		rcu_read_lock();
		return NULL;
	}

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

363
	if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) {
364 365 366 367
		rcu_read_lock();
		return NULL;
	}

Johannes Berg's avatar
Johannes Berg committed
368 369 370 371
	rcu_read_lock();
	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
	if (WARN_ON_ONCE(!chanctx_conf))
		return NULL;
372
	band = chanctx_conf->def.chan->band;
Johannes Berg's avatar
Johannes Berg committed
373 374
	rcu_read_unlock();

375 376 377 378 379 380 381 382 383
	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 */
384
	sband = local->hw.wiphy->bands[band];
385
	sta->sta.supp_rates[band] = supp_rates |
386
			ieee80211_mandatory_rates(sband);
387

388 389 390
	return ieee80211_ibss_finish_sta(sta, auth);
}

391 392 393 394 395 396 397 398 399 400 401 402 403 404
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);
}

405 406 407 408 409
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;
410 411
	struct sta_info *sta;
	u8 deauth_frame_buf[IEEE80211_DEAUTH_FRAME_LEN];
412 413 414 415 416 417 418 419 420

	lockdep_assert_held(&sdata->u.ibss.mtx);

	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
421 422 423
	ibss_dbg(sdata,
		 "RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n",
		 mgmt->sa, mgmt->da, mgmt->bssid, auth_transaction);
424 425 426 427

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

428
	sta_info_destroy_addr(sdata, mgmt->sa);
429
	sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 0, false);
430 431
	rcu_read_unlock();

432 433 434 435 436 437 438 439 440 441 442 443
	/*
	 * if we have any problem in allocating the new station, we reply with a
	 * DEAUTH frame to tell the other end that we had a problem
	 */
	if (!sta) {
		ieee80211_send_deauth_disassoc(sdata, sdata->u.ibss.bssid,
					       IEEE80211_STYPE_DEAUTH,
					       WLAN_REASON_UNSPECIFIED, true,
					       deauth_frame_buf);
		return;
	}

444 445 446 447 448 449
	/*
	 * 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.
	 */
450
	ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, 0, NULL, 0,
451
			    mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0, 0);
452 453
}

454
static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
455
				  struct ieee80211_mgmt *mgmt, size_t len,
456
				  struct ieee80211_rx_status *rx_status,
457
				  struct ieee802_11_elems *elems)
458 459 460
{
	struct ieee80211_local *local = sdata->local;
	int freq;
461
	struct cfg80211_bss *cbss;
462 463 464 465 466 467
	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;
468 469
	struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
	bool rates_updated = false;
470

471
	if (elems->ds_params)
472 473
		freq = ieee80211_channel_to_frequency(elems->ds_params[0],
						      band);
474 475 476 477 478 479 480 481
	else
		freq = rx_status->freq;

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

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

482
	if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
483
	    ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid)) {
484 485

		rcu_read_lock();
486
		sta = sta_info_get(sdata, mgmt->sa);
487

488 489
		if (elems->supp_rates) {
			supp_rates = ieee80211_sta_get_rates(local, elems,
490
							     band, NULL);
491 492 493 494 495 496
			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 |
497
					ieee80211_mandatory_rates(sband);
498

499
				if (sta->sta.supp_rates[band] != prev_rates) {
Johannes Berg's avatar
Johannes Berg committed
500 501 502 503
					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]);
504
					rates_updated = true;
505
				}
506 507
			} else {
				rcu_read_unlock();
508
				sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
509
						mgmt->sa, supp_rates, true);
510
			}
511
		}
512 513

		if (sta && elems->wmm_info)
514
			set_sta_flag(sta, WLAN_STA_WME);
515

516
		if (sta && elems->ht_operation && elems->ht_cap_elem &&
517 518
		    sdata->u.ibss.channel_type != NL80211_CHAN_NO_HT) {
			/* we both use HT */
519
			struct ieee80211_ht_cap htcap_ie;
520 521 522 523 524
			struct cfg80211_chan_def chandef;

			ieee80211_ht_oper_to_chandef(channel,
						     elems->ht_operation,
						     &chandef);
525

526
			memcpy(&htcap_ie, elems->ht_cap_elem, sizeof(htcap_ie));
527 528 529 530 531

			/*
			 * fall back to HT20 if we don't use or use
			 * the other extension channel
			 */
532
			if (cfg80211_get_chandef_type(&chandef) !=
533
						sdata->u.ibss.channel_type)
534 535 536 537 538
				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);
539 540
		}

541 542 543
		if (sta && rates_updated) {
			drv_sta_rc_update(local, sdata, &sta->sta,
					  IEEE80211_RC_SUPP_RATES_CHANGED);
544
			rate_control_rate_init(sta);
545
		}
546

547
		rcu_read_unlock();
548 549 550
	}

	bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
551
					channel);
552 553 554
	if (!bss)
		return;

555 556
	cbss = container_of((void *)bss, struct cfg80211_bss, priv);

Johannes Berg's avatar
Johannes Berg committed
557 558
	/* same for beacon and probe response */
	beacon_timestamp = le64_to_cpu(mgmt->u.beacon.timestamp);
559 560 561 562

	/* check if we need to merge IBSS */

	/* we use a fixed BSSID */
563
	if (sdata->u.ibss.fixed_bssid)
564 565 566
		goto put_bss;

	/* not an IBSS */
567
	if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
568 569 570
		goto put_bss;

	/* different channel */
Johannes Berg's avatar
Johannes Berg committed
571 572
	if (sdata->u.ibss.fixed_channel &&
	    sdata->u.ibss.channel != cbss->channel)
573 574 575 576 577 578 579 580
		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;

581
	/* same BSSID */
582
	if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid))
583 584
		goto put_bss;

585 586 587 588 589
	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);
590 591 592 593 594
	} else {
		/*
		 * second best option: get current TSF
		 * (will return -1 if not supported)
		 */
595
		rx_timestamp = drv_get_tsf(local, sdata);
596
	}
597

Johannes Berg's avatar
Johannes Berg committed
598 599 600 601 602 603 604
	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);
605 606

	if (beacon_timestamp > rx_timestamp) {
Johannes Berg's avatar
Johannes Berg committed
607 608 609
		ibss_dbg(sdata,
			 "beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n",
			 mgmt->bssid);
610
		ieee80211_sta_join_ibss(sdata, bss);
611
		supp_rates = ieee80211_sta_get_rates(local, elems, band, NULL);
612
		ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
613
				       supp_rates, true);
614
		rcu_read_unlock();
615 616 617 618 619 620
	}

 put_bss:
	ieee80211_rx_bss_put(local, bss);
}

621 622 623
void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata,
			      const u8 *bssid, const u8 *addr,
			      u32 supp_rates)
624
{
625
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
626 627
	struct ieee80211_local *local = sdata->local;
	struct sta_info *sta;
Johannes Berg's avatar
Johannes Berg committed
628
	struct ieee80211_chanctx_conf *chanctx_conf;
629
	struct ieee80211_supported_band *sband;
Johannes Berg's avatar
Johannes Berg committed
630
	int band;
631

632 633 634 635
	/*
	 * XXX: Consider removing the least recently used entry and
	 * 	allow new one to be added.
	 */
636
	if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
Johannes Berg's avatar
Johannes Berg committed
637
		net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
638
				    sdata->name, addr);
639
		return;
640 641
	}

642
	if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
643
		return;
644

645
	if (!ether_addr_equal(bssid, sdata->u.ibss.bssid))
646
		return;
647

Johannes Berg's avatar
Johannes Berg committed
648 649 650 651 652 653
	rcu_read_lock();
	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
	if (WARN_ON_ONCE(!chanctx_conf)) {
		rcu_read_unlock();
		return;
	}
654
	band = chanctx_conf->def.chan->band;
Johannes Berg's avatar
Johannes Berg committed
655 656
	rcu_read_unlock();

657
	sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
658
	if (!sta)
659
		return;
660

661
	sta->last_rx = jiffies;
662

663
	/* make sure mandatory rates are always added */
664
	sband = local->hw.wiphy->bands[band];
665
	sta->sta.supp_rates[band] = supp_rates |
666
			ieee80211_mandatory_rates(sband);
667

668 669 670 671
	spin_lock(&ifibss->incomplete_lock);
	list_add(&sta->list, &ifibss->incomplete_stations);
	spin_unlock(&ifibss->incomplete_lock);
	ieee80211_queue_work(&local->hw, &sdata->work);
672 673 674 675 676 677 678 679
}

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;

Johannes Berg's avatar
Johannes Berg committed
680 681
	lockdep_assert_held(&sdata->u.ibss.mtx);

682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697
	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;
}

698 699 700
/*
 * This function is called with state == IEEE80211_IBSS_MLME_JOINED
 */
701 702 703 704 705

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

Johannes Berg's avatar
Johannes Berg committed
706 707
	lockdep_assert_held(&ifibss->mtx);

708 709
	mod_timer(&ifibss->timer,
		  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
710 711

	ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
712

Sujith's avatar
Sujith committed
713 714 715 716
	if (time_before(jiffies, ifibss->last_scan_completed +
		       IEEE80211_IBSS_MERGE_INTERVAL))
		return;

717 718 719
	if (ieee80211_sta_active_ibss(sdata))
		return;

720
	if (ifibss->fixed_channel)
721 722
		return;

Johannes Berg's avatar
Johannes Berg committed
723 724
	sdata_info(sdata,
		   "No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n");
725

726 727
	ieee80211_request_ibss_scan(sdata, ifibss->ssid, ifibss->ssid_len,
				    NULL);
728 729
}

730
static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
731 732 733 734 735 736
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	u8 bssid[ETH_ALEN];
	u16 capability;
	int i;

Johannes Berg's avatar
Johannes Berg committed
737 738
	lockdep_assert_held(&ifibss->mtx);

739
	if (ifibss->fixed_bssid) {
740 741 742 743 744 745 746
		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++)
747
			bssid[i] ^= sdata->vif.addr[i];
748 749 750 751
		bssid[0] &= ~0x01;
		bssid[0] |= 0x02;
	}

Johannes Berg's avatar
Johannes Berg committed
752
	sdata_info(sdata, "Creating new IBSS network, BSSID %pM\n", bssid);
753 754 755

	capability = WLAN_CAPABILITY_IBSS;

Johannes Berg's avatar
Johannes Berg committed
756
	if (ifibss->privacy)
757 758 759 760
		capability |= WLAN_CAPABILITY_PRIVACY;
	else
		sdata->drop_unencrypted = 0;

761
	__ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
762
				  ifibss->channel, ifibss->basic_rates,
763
				  capability, 0, true);
764 765
}

766 767 768 769
/*
 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
 */

770
static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
771 772 773
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;
774
	struct cfg80211_bss *cbss;
775
	struct ieee80211_channel *chan = NULL;
776 777
	const u8 *bssid = NULL;
	int active_ibss;
778
	u16 capability;
779

Johannes Berg's avatar
Johannes Berg committed
780 781
	lockdep_assert_held(&ifibss->mtx);

782
	active_ibss = ieee80211_sta_active_ibss(sdata);
Johannes Berg's avatar
Johannes Berg committed
783
	ibss_dbg(sdata, "sta_find_ibss (active_ibss=%d)\n", active_ibss);
784 785

	if (active_ibss)
786
		return;
787

788
	capability = WLAN_CAPABILITY_IBSS;
Johannes Berg's avatar
Johannes Berg committed
789
	if (ifibss->privacy)
790
		capability |= WLAN_CAPABILITY_PRIVACY;
791 792 793 794 795
	if (ifibss->fixed_bssid)
		bssid = ifibss->bssid;
	if (ifibss->fixed_channel)
		chan = ifibss->channel;
	if (!is_zero_ether_addr(ifibss->bssid))
796
		bssid = ifibss->bssid;
797 798 799 800 801 802 803
	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;
804

805
		bss = (void *)cbss->priv;
Johannes Berg's avatar
Johannes Berg committed
806 807 808 809 810 811
		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);
812

813
		ieee80211_sta_join_ibss(sdata, bss);
814
		ieee80211_rx_bss_put(local, bss);
815
		return;
Reinette Chatre's avatar
Reinette Chatre committed
816
	}
817

Johannes Berg's avatar
Johannes Berg committed
818
	ibss_dbg(sdata, "sta_find_ibss: did not try to join ibss\n");
819 820

	/* Selected IBSS not found in current scan results - try to scan */
821
	if (time_after(jiffies, ifibss->last_scan_completed +
822
					IEEE80211_SCAN_INTERVAL)) {
Johannes Berg's avatar
Johannes Berg committed
823
		sdata_info(sdata, "Trigger new scan to find an IBSS to join\n");
824

825 826
		ieee80211_request_ibss_scan(sdata, ifibss->ssid,
					    ifibss->ssid_len, chan);
827
	} else {
828 829 830
		int interval = IEEE80211_SCAN_INTERVAL;

		if (time_after(jiffies, ifibss->ibss_join_req +
Johannes Berg's avatar
Johannes Berg committed
831 832
			       IEEE80211_IBSS_JOIN_TIMEOUT))
			ieee80211_sta_create_ibss(sdata);
833

834 835
		mod_timer(&ifibss->timer,
			  round_jiffies(jiffies + interval));
836 837 838 839
	}
}

static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
840
					struct sk_buff *req)
841
{
842
	struct ieee80211_mgmt *mgmt = (void *)req->data;
843 844
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;
845
	int tx_last_beacon, len = req->len;
846
	struct sk_buff *skb;
847
	struct beacon_data *presp;
848 849
	u8 *pos, *end;

Johannes Berg's avatar
Johannes Berg committed
850 851
	lockdep_assert_held(&ifibss->mtx);

852 853 854
	presp = rcu_dereference_protected(ifibss->presp,
					  lockdep_is_held(&ifibss->mtx));

855
	if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
856
	    len < 24 + 2 || !presp)
857 858
		return;

859
	tx_last_beacon = drv_tx_last_beacon(local);
860

Johannes Berg's avatar
Johannes Berg committed
861 862 863
	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);
864

865
	if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da))
866 867
		return;

868
	if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) &&
869
	    !is_broadcast_ether_addr(mgmt->bssid))
870 871 872 873 874 875
		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
876 877
		ibss_dbg(sdata, "Invalid SSID IE in ProbeReq from %pM\n",
			 mgmt->sa);
878 879 880 881
		return;
	}
	if (pos[1] != 0 &&
	    (pos[1] != ifibss->ssid_len ||
882
	     memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
883 884 885 886 887
		/* Ignore ProbeReq for foreign SSID */
		return;
	}

	/* Reply with ProbeResp */
888
	skb = dev_alloc_skb(local->tx_headroom + presp->head_len);
889 890 891
	if (!skb)
		return;

892 893 894 895 896
	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);
897 898
	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
	ieee80211_tx_skb(sdata, skb);
899 900
}

901 902 903 904
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)
905 906 907 908
{
	size_t baselen;
	struct ieee802_11_elems elems;