ibss.c 32.9 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 37
#include "rate.h"

#define IEEE80211_SCAN_INTERVAL (2 * HZ)
#define IEEE80211_SCAN_INTERVAL_SLOW (15 * 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


38 39 40
static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
				      const u8 *bssid, const int beacon_int,
				      struct ieee80211_channel *chan,
41
				      const u32 basic_rates,
42
				      const u16 capability, u64 tsf)
43 44 45
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;
46
	int rates, i;
47 48 49 50
	struct sk_buff *skb;
	struct ieee80211_mgmt *mgmt;
	u8 *pos;
	struct ieee80211_supported_band *sband;
Johannes Berg's avatar
Johannes Berg committed
51
	struct cfg80211_bss *bss;
52
	u32 bss_change;
53
	u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
54
	enum nl80211_channel_type channel_type;
55

Johannes Berg's avatar
Johannes Berg committed
56 57
	lockdep_assert_held(&ifibss->mtx);

58
	/* Reset own TSF to allow time synchronization work. */
59
	drv_reset_tsf(local, sdata);
60

61
	skb = ifibss->skb;
62
	RCU_INIT_POINTER(ifibss->presp, NULL);
63 64 65 66 67
	synchronize_rcu();
	skb->data = skb->head;
	skb->len = 0;
	skb_reset_tail_pointer(skb);
	skb_reserve(skb, sdata->local->hw.extra_tx_headroom);
68

69
	if (!ether_addr_equal(ifibss->bssid, bssid))
70
		sta_info_flush(sdata->local, sdata);
71

72 73 74
	/* 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;
75
		netif_carrier_off(sdata->dev);
76 77 78
		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IBSS);
	}

79 80
	memcpy(ifibss->bssid, bssid, ETH_ALEN);

81
	sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
82

83
	local->oper_channel = chan;
84
	channel_type = ifibss->channel_type;
85
	if (!cfg80211_can_beacon_sec_chan(local->hw.wiphy, chan, channel_type))
86 87 88 89 90 91 92
		channel_type = NL80211_CHAN_HT20;
	if (!ieee80211_set_channel_type(local, sdata, channel_type)) {
		/* can only fail due to HT40+/- mismatch */
		channel_type = NL80211_CHAN_HT20;
		WARN_ON(!ieee80211_set_channel_type(local, sdata,
						    NL80211_CHAN_HT20));
	}
93
	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
94

95
	sband = local->hw.wiphy->bands[chan->band];
96

97 98 99 100 101 102 103 104 105 106
	/* build supported rates array */
	pos = supp_rates;
	for (i = 0; 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);
	}

107
	/* Build IBSS probe response */
108
	mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon));
109 110 111
	memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
					  IEEE80211_STYPE_PROBE_RESP);
112
	eth_broadcast_addr(mgmt->da);
113
	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
114
	memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
115
	mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
116
	mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
117 118 119 120 121 122 123
	mgmt->u.beacon.capab_info = cpu_to_le16(capability);

	pos = skb_put(skb, 2 + ifibss->ssid_len);
	*pos++ = WLAN_EID_SSID;
	*pos++ = ifibss->ssid_len;
	memcpy(pos, ifibss->ssid, ifibss->ssid_len);

124
	rates = sband->n_bitrates;
125 126 127 128 129 130 131 132 133 134 135
	if (rates > 8)
		rates = 8;
	pos = skb_put(skb, 2 + rates);
	*pos++ = WLAN_EID_SUPP_RATES;
	*pos++ = rates;
	memcpy(pos, supp_rates, rates);

	if (sband->band == IEEE80211_BAND_2GHZ) {
		pos = skb_put(skb, 2 + 1);
		*pos++ = WLAN_EID_DS_PARAMS;
		*pos++ = 1;
136
		*pos++ = ieee80211_frequency_to_channel(chan->center_freq);
137 138 139 140 141 142 143 144 145
	}

	pos = skb_put(skb, 2 + 2);
	*pos++ = WLAN_EID_IBSS_PARAMS;
	*pos++ = 2;
	/* FIX: set ATIM window based on scan results */
	*pos++ = 0;
	*pos++ = 0;

146 147
	if (sband->n_bitrates > 8) {
		rates = sband->n_bitrates - 8;
148 149 150 151 152 153
		pos = skb_put(skb, 2 + rates);
		*pos++ = WLAN_EID_EXT_SUPP_RATES;
		*pos++ = rates;
		memcpy(pos, &supp_rates[8], rates);
	}

154 155 156 157
	if (ifibss->ie_len)
		memcpy(skb_put(skb, ifibss->ie_len),
		       ifibss->ie, ifibss->ie_len);

158 159 160 161
	/* add HT capability and information IEs */
	if (channel_type && sband->ht_cap.ht_supported) {
		pos = skb_put(skb, 4 +
				   sizeof(struct ieee80211_ht_cap) +
162
				   sizeof(struct ieee80211_ht_operation));
163 164
		pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap,
						sband->ht_cap.cap);
165 166 167 168 169
		/*
		 * 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
		 */
170
		pos = ieee80211_ie_build_ht_oper(pos, &sband->ht_cap,
171
						 chan, channel_type, 0);
172 173
	}

174
	if (local->hw.queues >= IEEE80211_NUM_ACS) {
175 176 177 178 179 180 181 182 183 184 185 186
		pos = skb_put(skb, 9);
		*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 */
	}

187
	rcu_assign_pointer(ifibss->presp, skb);
188

189
	sdata->vif.bss_conf.beacon_int = beacon_int;
190
	sdata->vif.bss_conf.basic_rates = basic_rates;
191 192 193 194 195
	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;
196
	bss_change |= BSS_CHANGED_BASIC_RATES;
197
	bss_change |= BSS_CHANGED_HT;
198 199
	bss_change |= BSS_CHANGED_IBSS;
	sdata->vif.bss_conf.ibss_joined = true;
200
	ieee80211_bss_info_change_notify(sdata, bss_change);
201

202
	ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates);
203 204

	ifibss->state = IEEE80211_IBSS_MLME_JOINED;
205 206
	mod_timer(&ifibss->timer,
		  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
207

208
	bss = cfg80211_inform_bss_frame(local->hw.wiphy, chan,
Johannes Berg's avatar
Johannes Berg committed
209 210
					mgmt, skb->len, 0, GFP_KERNEL);
	cfg80211_put_bss(bss);
211
	netif_carrier_on(sdata->dev);
212
	cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
213 214
}

215 216
static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
				    struct ieee80211_bss *bss)
217
{
218 219
	struct cfg80211_bss *cbss =
		container_of((void *)bss, struct cfg80211_bss, priv);
220 221 222
	struct ieee80211_supported_band *sband;
	u32 basic_rates;
	int i, j;
223
	u16 beacon_int = cbss->beacon_interval;
224

Johannes Berg's avatar
Johannes Berg committed
225 226
	lockdep_assert_held(&sdata->u.ibss.mtx);

227 228 229
	if (beacon_int < 10)
		beacon_int = 10;

230
	sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246

	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;
			}
		}
	}

247
	__ieee80211_sta_join_ibss(sdata, cbss->bssid,
248
				  beacon_int,
249
				  cbss->channel,
250
				  basic_rates,
251 252
				  cbss->capability,
				  cbss->tsf);
253 254
}

255 256
static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta,
						  bool auth)
257 258 259 260 261 262 263
	__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
264
	ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr);
265

266 267
	sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
	sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
268 269 270 271
	/* 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);
272 273 274 275 276 277

	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);
278
	if (auth && !sdata->u.ibss.auth_frame_registrations) {
Johannes Berg's avatar
Johannes Berg committed
279 280
		ibss_dbg(sdata,
			 "TX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=1)\n",
281
			 sdata->vif.addr, addr, sdata->u.ibss.bssid);
282 283 284
		ieee80211_send_auth(sdata, 1, WLAN_AUTH_OPEN, NULL, 0,
				    addr, sdata->u.ibss.bssid, NULL, 0, 0);
	}
285 286 287 288 289 290
	return sta;
}

static struct sta_info *
ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
		       const u8 *bssid, const u8 *addr,
291
		       u32 supp_rates, bool auth)
292 293 294 295 296
	__acquires(RCU)
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;
	struct sta_info *sta;
297
	int band = local->oper_channel->band;
298 299 300 301 302 303

	/*
	 * 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
304
		net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
305
				    sdata->name, addr);
306 307 308 309 310 311 312 313 314
		rcu_read_lock();
		return NULL;
	}

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

315
	if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) {
316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331
		rcu_read_lock();
		return NULL;
	}

	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 */
	sta->sta.supp_rates[band] = supp_rates |
			ieee80211_mandatory_rates(local, band);

332 333 334
	return ieee80211_ibss_finish_sta(sta, auth);
}

335 336 337 338 339 340 341 342 343 344 345 346 347 348
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);
}

349 350 351 352 353
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;
354 355
	struct sta_info *sta;
	u8 deauth_frame_buf[IEEE80211_DEAUTH_FRAME_LEN];
356 357 358 359 360 361 362 363 364 365 366

	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);

	if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1)
		return;
Johannes Berg's avatar
Johannes Berg committed
367 368 369
	ibss_dbg(sdata,
		 "RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n",
		 mgmt->sa, mgmt->da, mgmt->bssid, auth_transaction);
370
	sta_info_destroy_addr(sdata, mgmt->sa);
371
	sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 0, false);
372 373
	rcu_read_unlock();

374 375 376 377 378 379 380 381 382 383 384 385
	/*
	 * 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;
	}

386 387 388 389 390 391 392 393
	/*
	 * 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.
	 */
	ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0,
			    mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0);
394 395
}

396 397 398 399 400 401 402 403 404
static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
				  struct ieee80211_mgmt *mgmt,
				  size_t len,
				  struct ieee80211_rx_status *rx_status,
				  struct ieee802_11_elems *elems,
				  bool beacon)
{
	struct ieee80211_local *local = sdata->local;
	int freq;
405
	struct cfg80211_bss *cbss;
406 407 408 409 410 411
	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;
412 413
	struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
	bool rates_updated = false;
414 415

	if (elems->ds_params && elems->ds_params_len == 1)
416 417
		freq = ieee80211_channel_to_frequency(elems->ds_params[0],
						      band);
418 419 420 421 422 423 424 425
	else
		freq = rx_status->freq;

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

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

426
	if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
427
	    ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid)) {
428 429

		rcu_read_lock();
430
		sta = sta_info_get(sdata, mgmt->sa);
431

432 433
		if (elems->supp_rates) {
			supp_rates = ieee80211_sta_get_rates(local, elems,
434
							     band, NULL);
435 436 437 438 439 440 441
			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 |
					ieee80211_mandatory_rates(local, band);
442

443
				if (sta->sta.supp_rates[band] != prev_rates) {
Johannes Berg's avatar
Johannes Berg committed
444 445 446 447
					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]);
448
					rates_updated = true;
449
				}
450 451
			} else {
				rcu_read_unlock();
452
				sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
453
						mgmt->sa, supp_rates, true);
454
			}
455
		}
456 457

		if (sta && elems->wmm_info)
458
			set_sta_flag(sta, WLAN_STA_WME);
459

460
		if (sta && elems->ht_operation && elems->ht_cap_elem &&
461 462 463 464
		    sdata->u.ibss.channel_type != NL80211_CHAN_NO_HT) {
			/* we both use HT */
			struct ieee80211_sta_ht_cap sta_ht_cap_new;
			enum nl80211_channel_type channel_type =
465 466
				ieee80211_ht_oper_to_channel_type(
							elems->ht_operation);
467 468 469 470 471 472 473 474 475

			ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
							  elems->ht_cap_elem,
							  &sta_ht_cap_new);

			/*
			 * fall back to HT20 if we don't use or use
			 * the other extension channel
			 */
476 477
			if (!(channel_type == NL80211_CHAN_HT40MINUS ||
			      channel_type == NL80211_CHAN_HT40PLUS) ||
478 479 480 481 482 483 484 485 486 487 488 489
			    channel_type != sdata->u.ibss.channel_type)
				sta_ht_cap_new.cap &=
					~IEEE80211_HT_CAP_SUP_WIDTH_20_40;

			if (memcmp(&sta->sta.ht_cap, &sta_ht_cap_new,
				   sizeof(sta_ht_cap_new))) {
				memcpy(&sta->sta.ht_cap, &sta_ht_cap_new,
				       sizeof(sta_ht_cap_new));
				rates_updated = true;
			}
		}

490 491 492
		if (sta && rates_updated) {
			drv_sta_rc_update(local, sdata, &sta->sta,
					  IEEE80211_RC_SUPP_RATES_CHANGED);
493
			rate_control_rate_init(sta);
494
		}
495

496
		rcu_read_unlock();
497 498 499 500 501 502 503
	}

	bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
					channel, beacon);
	if (!bss)
		return;

504 505
	cbss = container_of((void *)bss, struct cfg80211_bss, priv);

506
	/* was just updated in ieee80211_bss_info_update */
507
	beacon_timestamp = cbss->tsf;
508 509 510 511

	/* check if we need to merge IBSS */

	/* we use a fixed BSSID */
512
	if (sdata->u.ibss.fixed_bssid)
513 514 515
		goto put_bss;

	/* not an IBSS */
516
	if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
517 518 519
		goto put_bss;

	/* different channel */
520
	if (cbss->channel != local->oper_channel)
521 522 523 524 525 526 527 528
		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;

529
	/* same BSSID */
530
	if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid))
531 532
		goto put_bss;

Johannes Berg's avatar
Johannes Berg committed
533
	if (rx_status->flag & RX_FLAG_MACTIME_MPDU) {
534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556
		/*
		 * For correct IBSS merging we need mactime; since mactime is
		 * defined as the time the first data symbol of the frame hits
		 * the PHY, and the timestamp of the beacon is defined as "the
		 * time that the data symbol containing the first bit of the
		 * timestamp is transmitted to the PHY plus the transmitting
		 * STA's delays through its local PHY from the MAC-PHY
		 * interface to its interface with the WM" (802.11 11.1.2)
		 * - equals the time this bit arrives at the receiver - we have
		 * to take into account the offset between the two.
		 *
		 * E.g. at 1 MBit that means mactime is 192 usec earlier
		 * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
		 */
		int rate;

		if (rx_status->flag & RX_FLAG_HT)
			rate = 65; /* TODO: HT rates */
		else
			rate = local->hw.wiphy->bands[band]->
				bitrates[rx_status->rate_idx].bitrate;

		rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
557 558 559 560 561
	} else {
		/*
		 * second best option: get current TSF
		 * (will return -1 if not supported)
		 */
562
		rx_timestamp = drv_get_tsf(local, sdata);
563
	}
564

Johannes Berg's avatar
Johannes Berg committed
565 566 567 568 569 570 571
	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);
572 573

	if (beacon_timestamp > rx_timestamp) {
Johannes Berg's avatar
Johannes Berg committed
574 575 576
		ibss_dbg(sdata,
			 "beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n",
			 mgmt->bssid);
577
		ieee80211_sta_join_ibss(sdata, bss);
578
		supp_rates = ieee80211_sta_get_rates(local, elems, band, NULL);
579
		ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
580
				       supp_rates, true);
581
		rcu_read_unlock();
582 583 584 585 586 587
	}

 put_bss:
	ieee80211_rx_bss_put(local, bss);
}

588 589 590
void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata,
			      const u8 *bssid, const u8 *addr,
			      u32 supp_rates)
591
{
592
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
593 594
	struct ieee80211_local *local = sdata->local;
	struct sta_info *sta;
595
	int band = local->oper_channel->band;
596

597 598 599 600
	/*
	 * XXX: Consider removing the least recently used entry and
	 * 	allow new one to be added.
	 */
601
	if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
Johannes Berg's avatar
Johannes Berg committed
602
		net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
603
				    sdata->name, addr);
604
		return;
605 606
	}

607
	if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
608
		return;
609

610
	if (!ether_addr_equal(bssid, sdata->u.ibss.bssid))
611
		return;
612

613
	sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
614
	if (!sta)
615
		return;
616

617
	sta->last_rx = jiffies;
618

619 620 621 622
	/* make sure mandatory rates are always added */
	sta->sta.supp_rates[band] = supp_rates |
			ieee80211_mandatory_rates(local, band);

623 624 625 626
	spin_lock(&ifibss->incomplete_lock);
	list_add(&sta->list, &ifibss->incomplete_stations);
	spin_unlock(&ifibss->incomplete_lock);
	ieee80211_queue_work(&local->hw, &sdata->work);
627 628 629 630 631 632 633 634
}

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
635 636
	lockdep_assert_held(&sdata->u.ibss.mtx);

637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652
	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;
}

653 654 655
/*
 * This function is called with state == IEEE80211_IBSS_MLME_JOINED
 */
656 657 658 659 660

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
661 662
	lockdep_assert_held(&ifibss->mtx);

663 664
	mod_timer(&ifibss->timer,
		  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
665 666

	ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
667

Sujith's avatar
Sujith committed
668 669 670 671
	if (time_before(jiffies, ifibss->last_scan_completed +
		       IEEE80211_IBSS_MERGE_INTERVAL))
		return;

672 673 674
	if (ieee80211_sta_active_ibss(sdata))
		return;

675
	if (ifibss->fixed_channel)
676 677
		return;

Johannes Berg's avatar
Johannes Berg committed
678 679
	sdata_info(sdata,
		   "No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n");
680

681
	ieee80211_request_internal_scan(sdata,
682
			ifibss->ssid, ifibss->ssid_len, NULL);
683 684
}

685
static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
686 687 688 689 690 691
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	u8 bssid[ETH_ALEN];
	u16 capability;
	int i;

Johannes Berg's avatar
Johannes Berg committed
692 693
	lockdep_assert_held(&ifibss->mtx);

694
	if (ifibss->fixed_bssid) {
695 696 697 698 699 700 701
		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++)
702
			bssid[i] ^= sdata->vif.addr[i];
703 704 705 706
		bssid[0] &= ~0x01;
		bssid[0] |= 0x02;
	}

Johannes Berg's avatar
Johannes Berg committed
707
	sdata_info(sdata, "Creating new IBSS network, BSSID %pM\n", bssid);
708 709 710

	capability = WLAN_CAPABILITY_IBSS;

Johannes Berg's avatar
Johannes Berg committed
711
	if (ifibss->privacy)
712 713 714 715
		capability |= WLAN_CAPABILITY_PRIVACY;
	else
		sdata->drop_unencrypted = 0;

716
	__ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
717
				  ifibss->channel, ifibss->basic_rates,
718
				  capability, 0);
719 720
}

721 722 723 724
/*
 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
 */

725
static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
726 727 728
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;
729
	struct cfg80211_bss *cbss;
730
	struct ieee80211_channel *chan = NULL;
731 732
	const u8 *bssid = NULL;
	int active_ibss;
733
	u16 capability;
734

Johannes Berg's avatar
Johannes Berg committed
735 736
	lockdep_assert_held(&ifibss->mtx);

737
	active_ibss = ieee80211_sta_active_ibss(sdata);
Johannes Berg's avatar
Johannes Berg committed
738
	ibss_dbg(sdata, "sta_find_ibss (active_ibss=%d)\n", active_ibss);
739 740

	if (active_ibss)
741
		return;
742

743
	capability = WLAN_CAPABILITY_IBSS;
Johannes Berg's avatar
Johannes Berg committed
744
	if (ifibss->privacy)
745
		capability |= WLAN_CAPABILITY_PRIVACY;
746 747 748 749 750
	if (ifibss->fixed_bssid)
		bssid = ifibss->bssid;
	if (ifibss->fixed_channel)
		chan = ifibss->channel;
	if (!is_zero_ether_addr(ifibss->bssid))
751
		bssid = ifibss->bssid;
752 753 754 755 756 757 758
	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;
759

760
		bss = (void *)cbss->priv;
Johannes Berg's avatar
Johannes Berg committed
761 762 763 764 765 766
		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);
767

768
		ieee80211_sta_join_ibss(sdata, bss);
769
		ieee80211_rx_bss_put(local, bss);
770
		return;
Reinette Chatre's avatar
Reinette Chatre committed
771
	}
772

Johannes Berg's avatar
Johannes Berg committed
773
	ibss_dbg(sdata, "sta_find_ibss: did not try to join ibss\n");
774 775

	/* Selected IBSS not found in current scan results - try to scan */
776
	if (time_after(jiffies, ifibss->last_scan_completed +
777
					IEEE80211_SCAN_INTERVAL)) {
Johannes Berg's avatar
Johannes Berg committed
778
		sdata_info(sdata, "Trigger new scan to find an IBSS to join\n");
779

780 781 782
		ieee80211_request_internal_scan(sdata,
				ifibss->ssid, ifibss->ssid_len,
				ifibss->fixed_channel ? ifibss->channel : NULL);
783
	} else {
784 785 786 787
		int interval = IEEE80211_SCAN_INTERVAL;

		if (time_after(jiffies, ifibss->ibss_join_req +
			       IEEE80211_IBSS_JOIN_TIMEOUT)) {
788 789 790 791
			if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
				ieee80211_sta_create_ibss(sdata);
				return;
			}
Johannes Berg's avatar
Johannes Berg committed
792
			sdata_info(sdata, "IBSS not allowed on %d MHz\n",
793
				   local->oper_channel->center_freq);
794 795 796 797 798 799

			/* No IBSS found - decrease scan interval and continue
			 * scanning. */
			interval = IEEE80211_SCAN_INTERVAL_SLOW;
		}

800 801
		mod_timer(&ifibss->timer,
			  round_jiffies(jiffies + interval));
802 803 804 805
	}
}

static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
806
					struct sk_buff *req)
807
{
808
	struct ieee80211_mgmt *mgmt = (void *)req->data;
809 810
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;
811
	int tx_last_beacon, len = req->len;
812 813
	struct sk_buff *skb;
	struct ieee80211_mgmt *resp;
814
	struct sk_buff *presp;
815 816
	u8 *pos, *end;

Johannes Berg's avatar
Johannes Berg committed
817 818
	lockdep_assert_held(&ifibss->mtx);

819 820 821
	presp = rcu_dereference_protected(ifibss->presp,
					  lockdep_is_held(&ifibss->mtx));

822
	if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
823
	    len < 24 + 2 || !presp)
824 825
		return;

826
	tx_last_beacon = drv_tx_last_beacon(local);
827

Johannes Berg's avatar
Johannes Berg committed
828 829 830
	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);
831

832
	if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da))
833 834
		return;

835
	if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) &&
836
	    !is_broadcast_ether_addr(mgmt->bssid))
837 838 839 840 841 842
		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
843 844
		ibss_dbg(sdata, "Invalid SSID IE in ProbeReq from %pM\n",
			 mgmt->sa);
845 846 847 848
		return;
	}
	if (pos[1] != 0 &&
	    (pos[1] != ifibss->ssid_len ||
849
	     memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
850 851 852 853 854
		/* Ignore ProbeReq for foreign SSID */
		return;
	}

	/* Reply with ProbeResp */
855
	skb = skb_copy(presp, GFP_KERNEL);
856 857 858 859 860
	if (!skb)
		return;

	resp = (struct ieee80211_mgmt *) skb->data;
	memcpy(resp->da, mgmt->sa, ETH_ALEN);
Johannes Berg's avatar
Johannes Berg committed
861
	ibss_dbg(sdata, "Sending ProbeResp to %pM\n", resp->da);
862 863
	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
	ieee80211_tx_skb(sdata, skb);
864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901
}

static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
					 struct ieee80211_mgmt *mgmt,
					 size_t len,
					 struct ieee80211_rx_status *rx_status)
{
	size_t baselen;
	struct ieee802_11_elems elems;

	baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
	if (baselen > len)
		return;

	ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
				&elems);

	ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
}

static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
				     struct ieee80211_mgmt *mgmt,
				     size_t len,
				     struct ieee80211_rx_status *rx_status)
{
	size_t baselen;
	struct ieee802_11_elems elems;

	/* Process beacon from the current BSS */
	baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
	if (baselen > len)
		return;

	ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);

	ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
}

902 903
void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
				   struct sk_buff *skb)
904 905 906 907 908
{
	struct ieee80211_rx_status *rx_status;
	struct ieee80211_mgmt *mgmt;
	u16 fc;

909
	rx_status = IEEE80211_SKB_RXCB(skb);
910 911 912
	mgmt = (struct ieee80211_mgmt *) skb->data;
	fc = le16_to_cpu(mgmt->frame_control);

Johannes Berg's avatar
Johannes Berg committed
913 914
	mutex_lock(&sdata->u.ibss.mtx);

915 916 917
	if (!sdata->u.ibss.ssid_len)
		goto mgmt_out; /* not ready to merge yet */

918 919
	switch (fc & IEEE80211_FCTL_STYPE) {
	case IEEE80211_STYPE_PROBE_REQ:
920
		ieee80211_rx_mgmt_probe_req(sdata, skb);
921 922 923 924 925 926 927 928 929 930 931 932
		break;
	case IEEE80211_STYPE_PROBE_RESP:
		ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
					     rx_status);
		break;
	case IEEE80211_STYPE_BEACON:
		ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
					 rx_status);
		break;
	case IEEE80211_STYPE_AUTH:
		ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
		break;
933 934 935
	case IEEE80211_STYPE_DEAUTH:
		ieee80211_rx_mgmt_deauth_ibss(sdata, mgmt, skb->len);
		break;
936
	}
Johannes Berg's avatar
Johannes Berg committed
937

938
 mgmt_out:
Johannes Berg's avatar
Johannes Berg committed
939
	mutex_unlock(&sdata->u.ibss.mtx);
940 941
}

942
void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
943
{
944
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
945
	struct sta_info *sta;
946

Johannes Berg's avatar
Johannes Berg committed
947 948 949 950 951 952 953 954 955
	mutex_lock(&ifibss->mtx);

	/*
	 * Work could be scheduled after scan or similar
	 * when we aren't even joined (or trying) with a
	 * network.
	 */
	if (!ifibss->ssid_len)
		goto out;
956

957 958 959 960 961 962 963
	spin_lock_bh(&ifibss->incomplete_lock);
	while (!list_empty(&ifibss->incomplete_stations)) {
		sta = list_first_entry(&ifibss->incomplete_stations,
				       struct sta_info, list);
		list_del(&sta->list);
		spin_unlock_bh(&ifibss->incomplete_lock);

964
		ieee80211_ibss_finish_sta(sta, true);
965 966 967 968 969
		rcu_read_unlock();
		spin_lock_bh(&ifibss->incomplete_lock);
	}
	spin_unlock_bh(&ifibss->incomplete_lock);

970 971 972 973 974 975 976 977 978 979 980 981
	switch (ifibss->state) {
	case IEEE80211_IBSS_MLME_SEARCH:
		ieee80211_sta_find_ibss(sdata);
		break;
	case IEEE80211_IBSS_MLME_JOINED:
		ieee80211_sta_merge_ibss(sdata);
		break;
	default:
		WARN_ON(1);
		break;
	}

Johannes Berg's avatar
Johannes Berg committed
982 983
 out:
	mutex_unlock(&ifibss->mtx);
984 985
}

986 987 988 989 990 991 992
static void ieee80211_ibss_timer(unsigned long data)
{
	struct ieee80211_sub_if_data *sdata =
		(struct ieee80211_sub_if_data *) data;
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;

993 994 995 996 997
	if (local->quiescing) {
		ifibss->timer_running = true;
		return;
	}

Johannes Berg's avatar
Johannes Berg committed
998
	ieee80211_queue_work(&local->hw, &sdata->work);