ibss.c 25.6 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 25
#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 <asm/unaligned.h>

#include "ieee80211_i.h"
26
#include "driver-ops.h"
27 28 29 30 31 32 33
#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)
34
#define IEEE80211_IBSS_MERGE_DELAY 0x400000
35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
#define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)

#define IEEE80211_IBSS_MAX_STA_ENTRIES 128


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, status_code;

	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);
	status_code = le16_to_cpu(mgmt->u.auth.status_code);

	/*
	 * 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.
	 */
	if (auth_alg == WLAN_AUTH_OPEN && auth_transaction == 1)
		ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0,
Johannes Berg's avatar
Johannes Berg committed
61
				    sdata->u.ibss.bssid, NULL, 0, 0);
62 63
}

64 65 66
static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
				      const u8 *bssid, const int beacon_int,
				      struct ieee80211_channel *chan,
67
				      const u32 basic_rates,
68
				      const u16 capability, u64 tsf)
69 70 71
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;
72
	int rates, i;
73 74 75 76
	struct sk_buff *skb;
	struct ieee80211_mgmt *mgmt;
	u8 *pos;
	struct ieee80211_supported_band *sband;
Johannes Berg's avatar
Johannes Berg committed
77
	struct cfg80211_bss *bss;
78
	u32 bss_change;
79
	u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
80 81 82

	/* Reset own TSF to allow time synchronization work. */
	drv_reset_tsf(local);
83

84 85 86 87 88 89 90
	skb = ifibss->skb;
	rcu_assign_pointer(ifibss->presp, NULL);
	synchronize_rcu();
	skb->data = skb->head;
	skb->len = 0;
	skb_reset_tail_pointer(skb);
	skb_reserve(skb, sdata->local->hw.extra_tx_headroom);
91

92 93
	if (memcmp(ifibss->bssid, bssid, ETH_ALEN))
		sta_info_flush(sdata->local, sdata);
94

95 96 97 98 99 100
	/* 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;
		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IBSS);
	}

101 102
	memcpy(ifibss->bssid, bssid, ETH_ALEN);

103
	sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
104

105
	local->oper_channel = chan;
106
	WARN_ON(!ieee80211_set_channel_type(local, sdata, NL80211_CHAN_NO_HT));
107
	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
108

109
	sband = local->hw.wiphy->bands[chan->band];
110

111 112 113 114 115 116 117 118 119 120
	/* 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);
	}

121
	/* Build IBSS probe response */
122
	mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon));
123 124 125 126
	memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
					  IEEE80211_STYPE_PROBE_RESP);
	memset(mgmt->da, 0xff, ETH_ALEN);
127
	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
128
	memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
129
	mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
130
	mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
131 132 133 134 135 136 137
	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);

138
	rates = sband->n_bitrates;
139 140 141 142 143 144 145 146 147 148 149
	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;
150
		*pos++ = ieee80211_frequency_to_channel(chan->center_freq);
151 152 153 154 155 156 157 158 159
	}

	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;

160 161
	if (sband->n_bitrates > 8) {
		rates = sband->n_bitrates - 8;
162 163 164 165 166 167
		pos = skb_put(skb, 2 + rates);
		*pos++ = WLAN_EID_EXT_SUPP_RATES;
		*pos++ = rates;
		memcpy(pos, &supp_rates[8], rates);
	}

168 169 170 171 172
	if (ifibss->ie_len)
		memcpy(skb_put(skb, ifibss->ie_len),
		       ifibss->ie, ifibss->ie_len);

	rcu_assign_pointer(ifibss->presp, skb);
173

174
	sdata->vif.bss_conf.beacon_int = beacon_int;
175
	sdata->vif.bss_conf.basic_rates = basic_rates;
176 177 178 179 180
	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;
181 182
	bss_change |= BSS_CHANGED_IBSS;
	sdata->vif.bss_conf.ibss_joined = true;
183
	ieee80211_bss_info_change_notify(sdata, bss_change);
184

185
	ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates);
186 187

	ifibss->state = IEEE80211_IBSS_MLME_JOINED;
188 189
	mod_timer(&ifibss->timer,
		  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
190

Johannes Berg's avatar
Johannes Berg committed
191 192 193
	bss = cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel,
					mgmt, skb->len, 0, GFP_KERNEL);
	cfg80211_put_bss(bss);
194
	cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
195 196
}

197 198
static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
				    struct ieee80211_bss *bss)
199
{
200 201
	struct cfg80211_bss *cbss =
		container_of((void *)bss, struct cfg80211_bss, priv);
202 203 204
	struct ieee80211_supported_band *sband;
	u32 basic_rates;
	int i, j;
205
	u16 beacon_int = cbss->beacon_interval;
206 207 208 209

	if (beacon_int < 10)
		beacon_int = 10;

210
	sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226

	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;
			}
		}
	}

227
	__ieee80211_sta_join_ibss(sdata, cbss->bssid,
228
				  beacon_int,
229
				  cbss->channel,
230
				  basic_rates,
231 232
				  cbss->capability,
				  cbss->tsf);
233 234 235 236 237 238 239 240 241 242 243
}

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;
244
	struct cfg80211_bss *cbss;
245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267
	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;

	if (elems->ds_params && elems->ds_params_len == 1)
		freq = ieee80211_channel_to_frequency(elems->ds_params[0]);
	else
		freq = rx_status->freq;

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

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

	if (sdata->vif.type == NL80211_IFTYPE_ADHOC && elems->supp_rates &&
	    memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) {
		supp_rates = ieee80211_sta_get_rates(local, elems, band);

		rcu_read_lock();

268
		sta = sta_info_get(sdata, mgmt->sa);
269 270 271 272 273 274 275 276
		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);

277
			if (sta->sta.supp_rates[band] != prev_rates) {
278 279
#ifdef CONFIG_MAC80211_IBSS_DEBUG
				printk(KERN_DEBUG "%s: updated supp_rates set "
280 281 282 283
				    "for %pM based on beacon/probe_response "
				    "(0x%x -> 0x%x)\n",
				    sdata->name, sta->sta.addr,
				    prev_rates, sta->sta.supp_rates[band]);
284
#endif
285 286
				rate_control_rate_init(sta);
			}
287 288 289 290 291 292
			rcu_read_unlock();
		} else {
			rcu_read_unlock();
			ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
					       supp_rates, GFP_KERNEL);
		}
293 294 295 296 297 298 299
	}

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

300 301
	cbss = container_of((void *)bss, struct cfg80211_bss, priv);

302
	/* was just updated in ieee80211_bss_info_update */
303
	beacon_timestamp = cbss->tsf;
304 305 306 307

	/* check if we need to merge IBSS */

	/* we use a fixed BSSID */
308
	if (sdata->u.ibss.fixed_bssid)
309 310 311
		goto put_bss;

	/* not an IBSS */
312
	if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
313 314 315
		goto put_bss;

	/* different channel */
316
	if (cbss->channel != local->oper_channel)
317 318 319 320 321 322 323 324
		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;

325
	/* same BSSID */
326
	if (memcmp(cbss->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0)
327 328
		goto put_bss;

329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352
	if (rx_status->flag & RX_FLAG_TSFT) {
		/*
		 * 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);
353 354 355 356 357 358 359
	} else {
		/*
		 * second best option: get current TSF
		 * (will return -1 if not supported)
		 */
		rx_timestamp = drv_get_tsf(local);
	}
360 361 362 363 364 365 366 367 368 369 370

#ifdef CONFIG_MAC80211_IBSS_DEBUG
	printk(KERN_DEBUG "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);
#endif

371 372 373 374
	/* give slow hardware some time to do the TSF sync */
	if (rx_timestamp < IEEE80211_IBSS_MERGE_DELAY)
		goto put_bss;

375 376 377 378
	if (beacon_timestamp > rx_timestamp) {
#ifdef CONFIG_MAC80211_IBSS_DEBUG
		printk(KERN_DEBUG "%s: beacon TSF higher than "
		       "local TSF - IBSS merge with BSSID %pM\n",
379
		       sdata->name, mgmt->bssid);
380 381
#endif
		ieee80211_sta_join_ibss(sdata, bss);
382
		supp_rates = ieee80211_sta_get_rates(local, elems, band);
383 384
		ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
				       supp_rates, GFP_KERNEL);
385 386 387 388 389 390 391 392 393 394 395 396
	}

 put_bss:
	ieee80211_rx_bss_put(local, bss);
}

/*
 * Add a new IBSS station, will also be called by the RX code when,
 * in IBSS mode, receiving a frame from a yet-unknown station, hence
 * must be callable in atomic context.
 */
struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
397 398
					u8 *bssid,u8 *addr, u32 supp_rates,
					gfp_t gfp)
399
{
400
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
401 402 403 404
	struct ieee80211_local *local = sdata->local;
	struct sta_info *sta;
	int band = local->hw.conf.channel->band;

405 406 407 408
	/*
	 * XXX: Consider removing the least recently used entry and
	 * 	allow new one to be added.
	 */
409
	if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
410 411
		if (net_ratelimit())
			printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
412
			       sdata->name, addr);
413 414 415
		return NULL;
	}

416 417 418
	if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
		return NULL;

419 420 421 422 423
	if (compare_ether_addr(bssid, sdata->u.ibss.bssid))
		return NULL;

#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
	printk(KERN_DEBUG "%s: Adding new IBSS station %pM (dev=%s)\n",
424
	       wiphy_name(local->hw.wiphy), addr, sdata->name);
425 426
#endif

427
	sta = sta_info_alloc(sdata, addr, gfp);
428 429 430 431 432 433 434 435 436 437 438
	if (!sta)
		return NULL;

	set_sta_flags(sta, WLAN_STA_AUTHORIZED);

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

	rate_control_rate_init(sta);

439
	/* If it fails, maybe we raced another insertion? */
440
	if (sta_info_insert(sta))
441
		return sta_info_get(sdata, addr);
442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466
	return sta;
}

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;

	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;
}

467 468 469
/*
 * This function is called with state == IEEE80211_IBSS_MLME_JOINED
 */
470 471 472 473 474

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

475 476
	mod_timer(&ifibss->timer,
		  round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
477 478

	ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
479

Sujith's avatar
Sujith committed
480 481 482 483
	if (time_before(jiffies, ifibss->last_scan_completed +
		       IEEE80211_IBSS_MERGE_INTERVAL))
		return;

484 485 486
	if (ieee80211_sta_active_ibss(sdata))
		return;

487
	if (ifibss->fixed_channel)
488 489 490
		return;

	printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
491
	       "IBSS networks with same SSID (merge)\n", sdata->name);
492

493 494 495
	ieee80211_request_internal_scan(sdata,
			ifibss->ssid, ifibss->ssid_len,
			ifibss->fixed_channel ? ifibss->channel : NULL);
496 497
}

498
static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
499 500 501 502 503 504 505 506
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;
	struct ieee80211_supported_band *sband;
	u8 bssid[ETH_ALEN];
	u16 capability;
	int i;

507
	if (ifibss->fixed_bssid) {
508 509 510 511 512 513 514
		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++)
515
			bssid[i] ^= sdata->vif.addr[i];
516 517 518 519 520
		bssid[0] &= ~0x01;
		bssid[0] |= 0x02;
	}

	printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n",
521
	       sdata->name, bssid);
522

523
	sband = local->hw.wiphy->bands[ifibss->channel->band];
524 525 526

	capability = WLAN_CAPABILITY_IBSS;

Johannes Berg's avatar
Johannes Berg committed
527
	if (ifibss->privacy)
528 529 530 531
		capability |= WLAN_CAPABILITY_PRIVACY;
	else
		sdata->drop_unencrypted = 0;

532
	__ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
533
				  ifibss->channel, ifibss->basic_rates,
534
				  capability, 0);
535 536
}

537 538 539 540
/*
 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
 */

541
static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
542 543 544
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;
545
	struct cfg80211_bss *cbss;
546
	struct ieee80211_channel *chan = NULL;
547 548
	const u8 *bssid = NULL;
	int active_ibss;
549
	u16 capability;
550 551 552 553

	active_ibss = ieee80211_sta_active_ibss(sdata);
#ifdef CONFIG_MAC80211_IBSS_DEBUG
	printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n",
554
	       sdata->name, active_ibss);
555 556 557
#endif /* CONFIG_MAC80211_IBSS_DEBUG */

	if (active_ibss)
558
		return;
559

560
	capability = WLAN_CAPABILITY_IBSS;
Johannes Berg's avatar
Johannes Berg committed
561
	if (ifibss->privacy)
562
		capability |= WLAN_CAPABILITY_PRIVACY;
563 564 565 566 567
	if (ifibss->fixed_bssid)
		bssid = ifibss->bssid;
	if (ifibss->fixed_channel)
		chan = ifibss->channel;
	if (!is_zero_ether_addr(ifibss->bssid))
568
		bssid = ifibss->bssid;
569 570 571 572 573 574 575
	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;
576

577
		bss = (void *)cbss->priv;
578 579
#ifdef CONFIG_MAC80211_IBSS_DEBUG
		printk(KERN_DEBUG "   sta_find_ibss: selected %pM current "
580
		       "%pM\n", cbss->bssid, ifibss->bssid);
581 582 583 584
#endif /* CONFIG_MAC80211_IBSS_DEBUG */

		printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM"
		       " based on configured SSID\n",
585
		       sdata->name, cbss->bssid);
586

587
		ieee80211_sta_join_ibss(sdata, bss);
588
		ieee80211_rx_bss_put(local, bss);
589
		return;
Reinette Chatre's avatar
Reinette Chatre committed
590
	}
591 592 593 594 595 596

#ifdef CONFIG_MAC80211_IBSS_DEBUG
	printk(KERN_DEBUG "   did not try to join ibss\n");
#endif /* CONFIG_MAC80211_IBSS_DEBUG */

	/* Selected IBSS not found in current scan results - try to scan */
597
	if (time_after(jiffies, ifibss->last_scan_completed +
598 599
					IEEE80211_SCAN_INTERVAL)) {
		printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
600
		       "join\n", sdata->name);
601

602 603 604
		ieee80211_request_internal_scan(sdata,
				ifibss->ssid, ifibss->ssid_len,
				ifibss->fixed_channel ? ifibss->channel : NULL);
605
	} else {
606 607 608 609
		int interval = IEEE80211_SCAN_INTERVAL;

		if (time_after(jiffies, ifibss->ibss_join_req +
			       IEEE80211_IBSS_JOIN_TIMEOUT)) {
610 611 612 613
			if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
				ieee80211_sta_create_ibss(sdata);
				return;
			}
614
			printk(KERN_DEBUG "%s: IBSS not allowed on"
615
			       " %d MHz\n", sdata->name,
616 617 618 619 620 621 622
			       local->hw.conf.channel->center_freq);

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

623 624
		mod_timer(&ifibss->timer,
			  round_jiffies(jiffies + interval));
625 626 627 628 629 630 631 632 633 634 635 636 637 638 639
	}
}

static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
					struct ieee80211_mgmt *mgmt,
					size_t len)
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;
	int tx_last_beacon;
	struct sk_buff *skb;
	struct ieee80211_mgmt *resp;
	u8 *pos, *end;

	if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
640
	    len < 24 + 2 || !ifibss->presp)
641 642
		return;

643
	tx_last_beacon = drv_tx_last_beacon(local);
644 645 646 647

#ifdef CONFIG_MAC80211_IBSS_DEBUG
	printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM"
	       " (tx_last_beacon=%d)\n",
648
	       sdata->name, mgmt->sa, mgmt->da,
649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665
	       mgmt->bssid, tx_last_beacon);
#endif /* CONFIG_MAC80211_IBSS_DEBUG */

	if (!tx_last_beacon)
		return;

	if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 &&
	    memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0)
		return;

	end = ((u8 *) mgmt) + len;
	pos = mgmt->u.probe_req.variable;
	if (pos[0] != WLAN_EID_SSID ||
	    pos + 2 + pos[1] > end) {
#ifdef CONFIG_MAC80211_IBSS_DEBUG
		printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq "
		       "from %pM\n",
666
		       sdata->name, mgmt->sa);
667 668 669 670 671
#endif
		return;
	}
	if (pos[1] != 0 &&
	    (pos[1] != ifibss->ssid_len ||
672
	     memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
673 674 675 676 677
		/* Ignore ProbeReq for foreign SSID */
		return;
	}

	/* Reply with ProbeResp */
678
	skb = skb_copy(ifibss->presp, GFP_KERNEL);
679 680 681 682 683 684 685
	if (!skb)
		return;

	resp = (struct ieee80211_mgmt *) skb->data;
	memcpy(resp->da, mgmt->sa, ETH_ALEN);
#ifdef CONFIG_MAC80211_IBSS_DEBUG
	printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n",
686
	       sdata->name, resp->da);
687
#endif /* CONFIG_MAC80211_IBSS_DEBUG */
688 689
	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
	ieee80211_tx_skb(sdata, skb);
690 691 692 693 694 695 696 697 698 699
}

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;

700
	if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN))
701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730
		return; /* ignore ProbeResp to foreign address */

	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);
}

731 732
void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
				   struct sk_buff *skb)
733 734 735 736 737
{
	struct ieee80211_rx_status *rx_status;
	struct ieee80211_mgmt *mgmt;
	u16 fc;

738
	rx_status = IEEE80211_SKB_RXCB(skb);
739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759
	mgmt = (struct ieee80211_mgmt *) skb->data;
	fc = le16_to_cpu(mgmt->frame_control);

	switch (fc & IEEE80211_FCTL_STYPE) {
	case IEEE80211_STYPE_PROBE_REQ:
		ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len);
		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;
	}
}

760
void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
761
{
762
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779

	if (!test_and_clear_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request))
		return;

	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;
	}
}

780 781 782 783 784 785
static void ieee80211_queue_ibss_work(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
	struct ieee80211_local *local = sdata->local;

	set_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request);
786
	ieee80211_queue_work(&local->hw, &sdata->work);
787 788
}

789 790 791 792 793 794 795
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;

796 797 798 799 800
	if (local->quiescing) {
		ifibss->timer_running = true;
		return;
	}

801
	ieee80211_queue_ibss_work(sdata);
802 803
}

804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823
#ifdef CONFIG_PM
void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;

	if (del_timer_sync(&ifibss->timer))
		ifibss->timer_running = true;
}

void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;

	if (ifibss->timer_running) {
		add_timer(&ifibss->timer);
		ifibss->timer_running = false;
	}
}
#endif

824 825 826 827 828 829 830 831 832 833 834
void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
{
	struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;

	setup_timer(&ifibss->timer, ieee80211_ibss_timer,
		    (unsigned long) sdata);
}

/* scan finished notification */
void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
{
835
	struct ieee80211_sub_if_data *sdata;
836

837 838
	mutex_lock(&local->iflist_mtx);
	list_for_each_entry(sdata, &local->interfaces, list) {
839
		if (!ieee80211_sdata_running(sdata))
840
			continue;
841 842
		if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
			continue;
843 844
		if (!sdata->u.ibss.ssid_len)
			continue;
845
		sdata->u.ibss.last_scan_completed = jiffies;
846
		ieee80211_queue_ibss_work(sdata);
847
	}
848
	mutex_unlock(&local->iflist_mtx);
849 850
}

851 852 853 854 855 856 857 858 859 860 861
int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
			struct cfg80211_ibss_params *params)
{
	struct sk_buff *skb;

	if (params->bssid) {
		memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
		sdata->u.ibss.fixed_bssid = true;
	} else
		sdata->u.ibss.fixed_bssid = false;

Johannes Berg's avatar
Johannes Berg committed
862
	sdata->u.ibss.privacy = params->privacy;
863
	sdata->u.ibss.basic_rates = params->basic_rates;
Johannes Berg's avatar
Johannes Berg committed
864

865 866
	sdata->vif.bss_conf.beacon_int = params->beacon_interval;

867 868 869
	sdata->u.ibss.channel = params->channel;
	sdata->u.ibss.fixed_channel = params->channel_fixed;

870 871 872
	/* fix ourselves to that channel now already */
	if (params->channel_fixed) {
		sdata->local->oper_channel = params->channel;
873 874
		WARN_ON(!ieee80211_set_channel_type(sdata->local, sdata,
						    NL80211_CHAN_NO_HT));
875 876
	}

877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896
	if (params->ie) {
		sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
					   GFP_KERNEL);
		if (sdata->u.ibss.ie)
			sdata->u.ibss.ie_len = params->ie_len;
	}

	skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
			    36 /* bitrates */ +
			    34 /* SSID */ +
			    3  /* DS params */ +
			    4  /* IBSS params */ +
			    params->ie_len);
	if (!skb)
		return -ENOMEM;

	sdata->u.ibss.skb = skb;
	sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
	sdata->u.ibss.ibss_join_req = jiffies;

897 898 899 900 901 902 903 904 905 906 907
	memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);

	/*
	 * The ssid_len setting below is used to see whether
	 * we are active, and we need all other settings
	 * before that may get visible.
	 */
	mb();

	sdata->u.ibss.ssid_len = params->ssid_len;

908 909
	ieee80211_recalc_idle(sdata->local);

910
	set_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
911
	ieee80211_queue_work(&sdata->local->hw, &sdata->work);
912 913 914 915 916 917 918 919 920 921

	return 0;
}

int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
{
	struct sk_buff *skb;

	del_timer_sync(&sdata->u.ibss.timer);
	clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
922
	cancel_work_sync(&sdata->work);
923 924 925 926 927 928 929 930
	clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);

	sta_info_flush(sdata->local, sdata);

	/* remove beacon */
	kfree(sdata->u.ibss.ie);
	skb = sdata->u.ibss.presp;
	rcu_assign_pointer(sdata->u.ibss.presp, NULL);
931 932 933
	sdata->vif.bss_conf.ibss_joined = false;
	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
						BSS_CHANGED_IBSS);
934 935 936
	synchronize_rcu();
	kfree_skb(skb);

Johannes Berg's avatar
Johannes Berg committed
937
	skb_queue_purge(&sdata->skb_queue);
938
	memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
939 940 941
	sdata->u.ibss.ssid_len = 0;

	ieee80211_recalc_idle(sdata->local);
942 943 944

	return 0;
}