1 /*
2 * IBSS mode implementation
3 * Copyright 2003-2008, Jouni Malinen <j@w1.fi>
4 * Copyright 2004, Instant802 Networks, Inc.
5 * Copyright 2005, Devicescape Software, Inc.
6 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
7 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
8 * Copyright 2009, Johannes Berg <johannes@sipsolutions.net>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 */
14
15 #include <linux/delay.h>
16 #include <linux/slab.h>
17 #include <linux/if_ether.h>
18 #include <linux/skbuff.h>
19 #include <linux/if_arp.h>
20 #include <linux/etherdevice.h>
21 #include <linux/rtnetlink.h>
22 #include <net/mac80211.h>
23 #include <asm/unaligned.h>
24
25 #include "ieee80211_i.h"
26 #include "driver-ops.h"
27 #include "rate.h"
28
29 #define IEEE80211_SCAN_INTERVAL (2 * HZ)
30 #define IEEE80211_SCAN_INTERVAL_SLOW (15 * HZ)
31 #define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)
32
33 #define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
34 #define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)
35
36 #define IEEE80211_IBSS_MAX_STA_ENTRIES 128
37
38
ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,size_t len)39 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
40 struct ieee80211_mgmt *mgmt,
41 size_t len)
42 {
43 u16 auth_alg, auth_transaction, status_code;
44
45 lockdep_assert_held(&sdata->u.ibss.mtx);
46
47 if (len < 24 + 6)
48 return;
49
50 auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
51 auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
52 status_code = le16_to_cpu(mgmt->u.auth.status_code);
53
54 /*
55 * IEEE 802.11 standard does not require authentication in IBSS
56 * networks and most implementations do not seem to use it.
57 * However, try to reply to authentication attempts if someone
58 * has actually implemented this.
59 */
60 if (auth_alg == WLAN_AUTH_OPEN && auth_transaction == 1)
61 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0,
62 sdata->u.ibss.bssid, NULL, 0, 0);
63 }
64
__ieee80211_sta_join_ibss(struct ieee80211_sub_if_data * sdata,const u8 * bssid,const int beacon_int,struct ieee80211_channel * chan,const u32 basic_rates,const u16 capability,u64 tsf)65 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
66 const u8 *bssid, const int beacon_int,
67 struct ieee80211_channel *chan,
68 const u32 basic_rates,
69 const u16 capability, u64 tsf)
70 {
71 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
72 struct ieee80211_local *local = sdata->local;
73 int rates, i;
74 struct sk_buff *skb;
75 struct ieee80211_mgmt *mgmt;
76 u8 *pos;
77 struct ieee80211_supported_band *sband;
78 struct cfg80211_bss *bss;
79 u32 bss_change;
80 u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
81
82 lockdep_assert_held(&ifibss->mtx);
83
84 /* Reset own TSF to allow time synchronization work. */
85 drv_reset_tsf(local);
86
87 skb = ifibss->skb;
88 rcu_assign_pointer(ifibss->presp, NULL);
89 synchronize_rcu();
90 skb->data = skb->head;
91 skb->len = 0;
92 skb_reset_tail_pointer(skb);
93 skb_reserve(skb, sdata->local->hw.extra_tx_headroom);
94
95 if (memcmp(ifibss->bssid, bssid, ETH_ALEN))
96 sta_info_flush(sdata->local, sdata);
97
98 /* if merging, indicate to driver that we leave the old IBSS */
99 if (sdata->vif.bss_conf.ibss_joined) {
100 sdata->vif.bss_conf.ibss_joined = false;
101 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IBSS);
102 }
103
104 memcpy(ifibss->bssid, bssid, ETH_ALEN);
105
106 sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
107
108 local->oper_channel = chan;
109 WARN_ON(!ieee80211_set_channel_type(local, sdata, NL80211_CHAN_NO_HT));
110 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
111
112 sband = local->hw.wiphy->bands[chan->band];
113
114 /* build supported rates array */
115 pos = supp_rates;
116 for (i = 0; i < sband->n_bitrates; i++) {
117 int rate = sband->bitrates[i].bitrate;
118 u8 basic = 0;
119 if (basic_rates & BIT(i))
120 basic = 0x80;
121 *pos++ = basic | (u8) (rate / 5);
122 }
123
124 /* Build IBSS probe response */
125 mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon));
126 memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
127 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
128 IEEE80211_STYPE_PROBE_RESP);
129 memset(mgmt->da, 0xff, ETH_ALEN);
130 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
131 memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
132 mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
133 mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
134 mgmt->u.beacon.capab_info = cpu_to_le16(capability);
135
136 pos = skb_put(skb, 2 + ifibss->ssid_len);
137 *pos++ = WLAN_EID_SSID;
138 *pos++ = ifibss->ssid_len;
139 memcpy(pos, ifibss->ssid, ifibss->ssid_len);
140
141 rates = sband->n_bitrates;
142 if (rates > 8)
143 rates = 8;
144 pos = skb_put(skb, 2 + rates);
145 *pos++ = WLAN_EID_SUPP_RATES;
146 *pos++ = rates;
147 memcpy(pos, supp_rates, rates);
148
149 if (sband->band == IEEE80211_BAND_2GHZ) {
150 pos = skb_put(skb, 2 + 1);
151 *pos++ = WLAN_EID_DS_PARAMS;
152 *pos++ = 1;
153 *pos++ = ieee80211_frequency_to_channel(chan->center_freq);
154 }
155
156 pos = skb_put(skb, 2 + 2);
157 *pos++ = WLAN_EID_IBSS_PARAMS;
158 *pos++ = 2;
159 /* FIX: set ATIM window based on scan results */
160 *pos++ = 0;
161 *pos++ = 0;
162
163 if (sband->n_bitrates > 8) {
164 rates = sband->n_bitrates - 8;
165 pos = skb_put(skb, 2 + rates);
166 *pos++ = WLAN_EID_EXT_SUPP_RATES;
167 *pos++ = rates;
168 memcpy(pos, &supp_rates[8], rates);
169 }
170
171 if (ifibss->ie_len)
172 memcpy(skb_put(skb, ifibss->ie_len),
173 ifibss->ie, ifibss->ie_len);
174
175 if (local->hw.queues >= 4) {
176 pos = skb_put(skb, 9);
177 *pos++ = WLAN_EID_VENDOR_SPECIFIC;
178 *pos++ = 7; /* len */
179 *pos++ = 0x00; /* Microsoft OUI 00:50:F2 */
180 *pos++ = 0x50;
181 *pos++ = 0xf2;
182 *pos++ = 2; /* WME */
183 *pos++ = 0; /* WME info */
184 *pos++ = 1; /* WME ver */
185 *pos++ = 0; /* U-APSD no in use */
186 }
187
188 rcu_assign_pointer(ifibss->presp, skb);
189
190 sdata->vif.bss_conf.beacon_int = beacon_int;
191 sdata->vif.bss_conf.basic_rates = basic_rates;
192 bss_change = BSS_CHANGED_BEACON_INT;
193 bss_change |= ieee80211_reset_erp_info(sdata);
194 bss_change |= BSS_CHANGED_BSSID;
195 bss_change |= BSS_CHANGED_BEACON;
196 bss_change |= BSS_CHANGED_BEACON_ENABLED;
197 bss_change |= BSS_CHANGED_BASIC_RATES;
198 bss_change |= BSS_CHANGED_IBSS;
199 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 mod_timer(&ifibss->timer,
206 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
207
208 bss = cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel,
209 mgmt, skb->len, 0, GFP_KERNEL);
210 cfg80211_put_bss(bss);
211 cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
212 }
213
ieee80211_sta_join_ibss(struct ieee80211_sub_if_data * sdata,struct ieee80211_bss * bss)214 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
215 struct ieee80211_bss *bss)
216 {
217 struct cfg80211_bss *cbss =
218 container_of((void *)bss, struct cfg80211_bss, priv);
219 struct ieee80211_supported_band *sband;
220 u32 basic_rates;
221 int i, j;
222 u16 beacon_int = cbss->beacon_interval;
223
224 lockdep_assert_held(&sdata->u.ibss.mtx);
225
226 if (beacon_int < 10)
227 beacon_int = 10;
228
229 sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
230
231 basic_rates = 0;
232
233 for (i = 0; i < bss->supp_rates_len; i++) {
234 int rate = (bss->supp_rates[i] & 0x7f) * 5;
235 bool is_basic = !!(bss->supp_rates[i] & 0x80);
236
237 for (j = 0; j < sband->n_bitrates; j++) {
238 if (sband->bitrates[j].bitrate == rate) {
239 if (is_basic)
240 basic_rates |= BIT(j);
241 break;
242 }
243 }
244 }
245
246 __ieee80211_sta_join_ibss(sdata, cbss->bssid,
247 beacon_int,
248 cbss->channel,
249 basic_rates,
250 cbss->capability,
251 cbss->tsf);
252 }
253
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)254 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
255 struct ieee80211_mgmt *mgmt,
256 size_t len,
257 struct ieee80211_rx_status *rx_status,
258 struct ieee802_11_elems *elems,
259 bool beacon)
260 {
261 struct ieee80211_local *local = sdata->local;
262 int freq;
263 struct cfg80211_bss *cbss;
264 struct ieee80211_bss *bss;
265 struct sta_info *sta;
266 struct ieee80211_channel *channel;
267 u64 beacon_timestamp, rx_timestamp;
268 u32 supp_rates = 0;
269 enum ieee80211_band band = rx_status->band;
270
271 if (elems->ds_params && elems->ds_params_len == 1)
272 freq = ieee80211_channel_to_frequency(elems->ds_params[0],
273 band);
274 else
275 freq = rx_status->freq;
276
277 channel = ieee80211_get_channel(local->hw.wiphy, freq);
278
279 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
280 return;
281
282 if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
283 memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) {
284
285 rcu_read_lock();
286 sta = sta_info_get(sdata, mgmt->sa);
287
288 if (elems->supp_rates) {
289 supp_rates = ieee80211_sta_get_rates(local, elems,
290 band);
291 if (sta) {
292 u32 prev_rates;
293
294 prev_rates = sta->sta.supp_rates[band];
295 /* make sure mandatory rates are always added */
296 sta->sta.supp_rates[band] = supp_rates |
297 ieee80211_mandatory_rates(local, band);
298
299 if (sta->sta.supp_rates[band] != prev_rates) {
300 #ifdef CONFIG_MAC80211_IBSS_DEBUG
301 printk(KERN_DEBUG
302 "%s: updated supp_rates set "
303 "for %pM based on beacon"
304 "/probe_resp (0x%x -> 0x%x)\n",
305 sdata->name, sta->sta.addr,
306 prev_rates,
307 sta->sta.supp_rates[band]);
308 #endif
309 rate_control_rate_init(sta);
310 }
311 } else
312 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
313 mgmt->sa, supp_rates,
314 GFP_ATOMIC);
315 }
316
317 if (sta && elems->wmm_info)
318 set_sta_flags(sta, WLAN_STA_WME);
319
320 rcu_read_unlock();
321 }
322
323 bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
324 channel, beacon);
325 if (!bss)
326 return;
327
328 cbss = container_of((void *)bss, struct cfg80211_bss, priv);
329
330 /* was just updated in ieee80211_bss_info_update */
331 beacon_timestamp = cbss->tsf;
332
333 /* check if we need to merge IBSS */
334
335 /* we use a fixed BSSID */
336 if (sdata->u.ibss.fixed_bssid)
337 goto put_bss;
338
339 /* not an IBSS */
340 if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
341 goto put_bss;
342
343 /* different channel */
344 if (cbss->channel != local->oper_channel)
345 goto put_bss;
346
347 /* different SSID */
348 if (elems->ssid_len != sdata->u.ibss.ssid_len ||
349 memcmp(elems->ssid, sdata->u.ibss.ssid,
350 sdata->u.ibss.ssid_len))
351 goto put_bss;
352
353 /* same BSSID */
354 if (memcmp(cbss->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0)
355 goto put_bss;
356
357 if (rx_status->flag & RX_FLAG_MACTIME_MPDU) {
358 /*
359 * For correct IBSS merging we need mactime; since mactime is
360 * defined as the time the first data symbol of the frame hits
361 * the PHY, and the timestamp of the beacon is defined as "the
362 * time that the data symbol containing the first bit of the
363 * timestamp is transmitted to the PHY plus the transmitting
364 * STA's delays through its local PHY from the MAC-PHY
365 * interface to its interface with the WM" (802.11 11.1.2)
366 * - equals the time this bit arrives at the receiver - we have
367 * to take into account the offset between the two.
368 *
369 * E.g. at 1 MBit that means mactime is 192 usec earlier
370 * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
371 */
372 int rate;
373
374 if (rx_status->flag & RX_FLAG_HT)
375 rate = 65; /* TODO: HT rates */
376 else
377 rate = local->hw.wiphy->bands[band]->
378 bitrates[rx_status->rate_idx].bitrate;
379
380 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
381 } else {
382 /*
383 * second best option: get current TSF
384 * (will return -1 if not supported)
385 */
386 rx_timestamp = drv_get_tsf(local);
387 }
388
389 #ifdef CONFIG_MAC80211_IBSS_DEBUG
390 printk(KERN_DEBUG "RX beacon SA=%pM BSSID="
391 "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
392 mgmt->sa, mgmt->bssid,
393 (unsigned long long)rx_timestamp,
394 (unsigned long long)beacon_timestamp,
395 (unsigned long long)(rx_timestamp - beacon_timestamp),
396 jiffies);
397 #endif
398
399 if (beacon_timestamp > rx_timestamp) {
400 #ifdef CONFIG_MAC80211_IBSS_DEBUG
401 printk(KERN_DEBUG "%s: beacon TSF higher than "
402 "local TSF - IBSS merge with BSSID %pM\n",
403 sdata->name, mgmt->bssid);
404 #endif
405 ieee80211_sta_join_ibss(sdata, bss);
406 supp_rates = ieee80211_sta_get_rates(local, elems, band);
407 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
408 supp_rates, GFP_KERNEL);
409 }
410
411 put_bss:
412 ieee80211_rx_bss_put(local, bss);
413 }
414
415 /*
416 * Add a new IBSS station, will also be called by the RX code when,
417 * in IBSS mode, receiving a frame from a yet-unknown station, hence
418 * must be callable in atomic context.
419 */
ieee80211_ibss_add_sta(struct ieee80211_sub_if_data * sdata,u8 * bssid,u8 * addr,u32 supp_rates,gfp_t gfp)420 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
421 u8 *bssid,u8 *addr, u32 supp_rates,
422 gfp_t gfp)
423 {
424 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
425 struct ieee80211_local *local = sdata->local;
426 struct sta_info *sta;
427 int band = local->hw.conf.channel->band;
428
429 /*
430 * XXX: Consider removing the least recently used entry and
431 * allow new one to be added.
432 */
433 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
434 if (net_ratelimit())
435 printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
436 sdata->name, addr);
437 return NULL;
438 }
439
440 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
441 return NULL;
442
443 if (compare_ether_addr(bssid, sdata->u.ibss.bssid))
444 return NULL;
445
446 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
447 wiphy_debug(local->hw.wiphy, "Adding new IBSS station %pM (dev=%s)\n",
448 addr, sdata->name);
449 #endif
450
451 sta = sta_info_alloc(sdata, addr, gfp);
452 if (!sta)
453 return NULL;
454
455 sta->last_rx = jiffies;
456 set_sta_flags(sta, WLAN_STA_AUTHORIZED);
457
458 /* make sure mandatory rates are always added */
459 sta->sta.supp_rates[band] = supp_rates |
460 ieee80211_mandatory_rates(local, band);
461
462 rate_control_rate_init(sta);
463
464 /* If it fails, maybe we raced another insertion? */
465 if (sta_info_insert(sta))
466 return sta_info_get(sdata, addr);
467 return sta;
468 }
469
ieee80211_sta_active_ibss(struct ieee80211_sub_if_data * sdata)470 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
471 {
472 struct ieee80211_local *local = sdata->local;
473 int active = 0;
474 struct sta_info *sta;
475
476 lockdep_assert_held(&sdata->u.ibss.mtx);
477
478 rcu_read_lock();
479
480 list_for_each_entry_rcu(sta, &local->sta_list, list) {
481 if (sta->sdata == sdata &&
482 time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
483 jiffies)) {
484 active++;
485 break;
486 }
487 }
488
489 rcu_read_unlock();
490
491 return active;
492 }
493
494 /*
495 * This function is called with state == IEEE80211_IBSS_MLME_JOINED
496 */
497
ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data * sdata)498 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
499 {
500 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
501
502 lockdep_assert_held(&ifibss->mtx);
503
504 mod_timer(&ifibss->timer,
505 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
506
507 ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
508
509 if (time_before(jiffies, ifibss->last_scan_completed +
510 IEEE80211_IBSS_MERGE_INTERVAL))
511 return;
512
513 if (ieee80211_sta_active_ibss(sdata))
514 return;
515
516 if (ifibss->fixed_channel)
517 return;
518
519 printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
520 "IBSS networks with same SSID (merge)\n", sdata->name);
521
522 ieee80211_request_internal_scan(sdata,
523 ifibss->ssid, ifibss->ssid_len,
524 ifibss->fixed_channel ? ifibss->channel : NULL);
525 }
526
ieee80211_sta_create_ibss(struct ieee80211_sub_if_data * sdata)527 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
528 {
529 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
530 struct ieee80211_local *local = sdata->local;
531 struct ieee80211_supported_band *sband;
532 u8 bssid[ETH_ALEN];
533 u16 capability;
534 int i;
535
536 lockdep_assert_held(&ifibss->mtx);
537
538 if (ifibss->fixed_bssid) {
539 memcpy(bssid, ifibss->bssid, ETH_ALEN);
540 } else {
541 /* Generate random, not broadcast, locally administered BSSID. Mix in
542 * own MAC address to make sure that devices that do not have proper
543 * random number generator get different BSSID. */
544 get_random_bytes(bssid, ETH_ALEN);
545 for (i = 0; i < ETH_ALEN; i++)
546 bssid[i] ^= sdata->vif.addr[i];
547 bssid[0] &= ~0x01;
548 bssid[0] |= 0x02;
549 }
550
551 printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n",
552 sdata->name, bssid);
553
554 sband = local->hw.wiphy->bands[ifibss->channel->band];
555
556 capability = WLAN_CAPABILITY_IBSS;
557
558 if (ifibss->privacy)
559 capability |= WLAN_CAPABILITY_PRIVACY;
560 else
561 sdata->drop_unencrypted = 0;
562
563 __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
564 ifibss->channel, ifibss->basic_rates,
565 capability, 0);
566 }
567
568 /*
569 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
570 */
571
ieee80211_sta_find_ibss(struct ieee80211_sub_if_data * sdata)572 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
573 {
574 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
575 struct ieee80211_local *local = sdata->local;
576 struct cfg80211_bss *cbss;
577 struct ieee80211_channel *chan = NULL;
578 const u8 *bssid = NULL;
579 int active_ibss;
580 u16 capability;
581
582 lockdep_assert_held(&ifibss->mtx);
583
584 active_ibss = ieee80211_sta_active_ibss(sdata);
585 #ifdef CONFIG_MAC80211_IBSS_DEBUG
586 printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n",
587 sdata->name, active_ibss);
588 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
589
590 if (active_ibss)
591 return;
592
593 capability = WLAN_CAPABILITY_IBSS;
594 if (ifibss->privacy)
595 capability |= WLAN_CAPABILITY_PRIVACY;
596 if (ifibss->fixed_bssid)
597 bssid = ifibss->bssid;
598 if (ifibss->fixed_channel)
599 chan = ifibss->channel;
600 if (!is_zero_ether_addr(ifibss->bssid))
601 bssid = ifibss->bssid;
602 cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
603 ifibss->ssid, ifibss->ssid_len,
604 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
605 capability);
606
607 if (cbss) {
608 struct ieee80211_bss *bss;
609
610 bss = (void *)cbss->priv;
611 #ifdef CONFIG_MAC80211_IBSS_DEBUG
612 printk(KERN_DEBUG " sta_find_ibss: selected %pM current "
613 "%pM\n", cbss->bssid, ifibss->bssid);
614 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
615
616 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM"
617 " based on configured SSID\n",
618 sdata->name, cbss->bssid);
619
620 ieee80211_sta_join_ibss(sdata, bss);
621 ieee80211_rx_bss_put(local, bss);
622 return;
623 }
624
625 #ifdef CONFIG_MAC80211_IBSS_DEBUG
626 printk(KERN_DEBUG " did not try to join ibss\n");
627 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
628
629 /* Selected IBSS not found in current scan results - try to scan */
630 if (time_after(jiffies, ifibss->last_scan_completed +
631 IEEE80211_SCAN_INTERVAL)) {
632 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
633 "join\n", sdata->name);
634
635 ieee80211_request_internal_scan(sdata,
636 ifibss->ssid, ifibss->ssid_len,
637 ifibss->fixed_channel ? ifibss->channel : NULL);
638 } else {
639 int interval = IEEE80211_SCAN_INTERVAL;
640
641 if (time_after(jiffies, ifibss->ibss_join_req +
642 IEEE80211_IBSS_JOIN_TIMEOUT)) {
643 if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
644 ieee80211_sta_create_ibss(sdata);
645 return;
646 }
647 printk(KERN_DEBUG "%s: IBSS not allowed on"
648 " %d MHz\n", sdata->name,
649 local->hw.conf.channel->center_freq);
650
651 /* No IBSS found - decrease scan interval and continue
652 * scanning. */
653 interval = IEEE80211_SCAN_INTERVAL_SLOW;
654 }
655
656 mod_timer(&ifibss->timer,
657 round_jiffies(jiffies + interval));
658 }
659 }
660
ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data * sdata,struct sk_buff * req)661 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
662 struct sk_buff *req)
663 {
664 struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(req);
665 struct ieee80211_mgmt *mgmt = (void *)req->data;
666 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
667 struct ieee80211_local *local = sdata->local;
668 int tx_last_beacon, len = req->len;
669 struct sk_buff *skb;
670 struct ieee80211_mgmt *resp;
671 u8 *pos, *end;
672
673 lockdep_assert_held(&ifibss->mtx);
674
675 if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
676 len < 24 + 2 || !ifibss->presp)
677 return;
678
679 tx_last_beacon = drv_tx_last_beacon(local);
680
681 #ifdef CONFIG_MAC80211_IBSS_DEBUG
682 printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM"
683 " (tx_last_beacon=%d)\n",
684 sdata->name, mgmt->sa, mgmt->da,
685 mgmt->bssid, tx_last_beacon);
686 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
687
688 if (!tx_last_beacon && !(rx_status->rx_flags & IEEE80211_RX_RA_MATCH))
689 return;
690
691 if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 &&
692 memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0)
693 return;
694
695 end = ((u8 *) mgmt) + len;
696 pos = mgmt->u.probe_req.variable;
697 if (pos[0] != WLAN_EID_SSID ||
698 pos + 2 + pos[1] > end) {
699 #ifdef CONFIG_MAC80211_IBSS_DEBUG
700 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq "
701 "from %pM\n",
702 sdata->name, mgmt->sa);
703 #endif
704 return;
705 }
706 if (pos[1] != 0 &&
707 (pos[1] != ifibss->ssid_len ||
708 memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
709 /* Ignore ProbeReq for foreign SSID */
710 return;
711 }
712
713 /* Reply with ProbeResp */
714 skb = skb_copy(ifibss->presp, GFP_KERNEL);
715 if (!skb)
716 return;
717
718 resp = (struct ieee80211_mgmt *) skb->data;
719 memcpy(resp->da, mgmt->sa, ETH_ALEN);
720 #ifdef CONFIG_MAC80211_IBSS_DEBUG
721 printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n",
722 sdata->name, resp->da);
723 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
724 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
725 ieee80211_tx_skb(sdata, skb);
726 }
727
ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,size_t len,struct ieee80211_rx_status * rx_status)728 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
729 struct ieee80211_mgmt *mgmt,
730 size_t len,
731 struct ieee80211_rx_status *rx_status)
732 {
733 size_t baselen;
734 struct ieee802_11_elems elems;
735
736 if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN))
737 return; /* ignore ProbeResp to foreign address */
738
739 baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
740 if (baselen > len)
741 return;
742
743 ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
744 &elems);
745
746 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
747 }
748
ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data * sdata,struct ieee80211_mgmt * mgmt,size_t len,struct ieee80211_rx_status * rx_status)749 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
750 struct ieee80211_mgmt *mgmt,
751 size_t len,
752 struct ieee80211_rx_status *rx_status)
753 {
754 size_t baselen;
755 struct ieee802_11_elems elems;
756
757 /* Process beacon from the current BSS */
758 baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
759 if (baselen > len)
760 return;
761
762 ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
763
764 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
765 }
766
ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)767 void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
768 struct sk_buff *skb)
769 {
770 struct ieee80211_rx_status *rx_status;
771 struct ieee80211_mgmt *mgmt;
772 u16 fc;
773
774 rx_status = IEEE80211_SKB_RXCB(skb);
775 mgmt = (struct ieee80211_mgmt *) skb->data;
776 fc = le16_to_cpu(mgmt->frame_control);
777
778 mutex_lock(&sdata->u.ibss.mtx);
779
780 if (!sdata->u.ibss.ssid_len)
781 goto mgmt_out; /* not ready to merge yet */
782
783 switch (fc & IEEE80211_FCTL_STYPE) {
784 case IEEE80211_STYPE_PROBE_REQ:
785 ieee80211_rx_mgmt_probe_req(sdata, skb);
786 break;
787 case IEEE80211_STYPE_PROBE_RESP:
788 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
789 rx_status);
790 break;
791 case IEEE80211_STYPE_BEACON:
792 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
793 rx_status);
794 break;
795 case IEEE80211_STYPE_AUTH:
796 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
797 break;
798 }
799
800 mgmt_out:
801 mutex_unlock(&sdata->u.ibss.mtx);
802 }
803
ieee80211_ibss_work(struct ieee80211_sub_if_data * sdata)804 void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
805 {
806 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
807
808 mutex_lock(&ifibss->mtx);
809
810 /*
811 * Work could be scheduled after scan or similar
812 * when we aren't even joined (or trying) with a
813 * network.
814 */
815 if (!ifibss->ssid_len)
816 goto out;
817
818 switch (ifibss->state) {
819 case IEEE80211_IBSS_MLME_SEARCH:
820 ieee80211_sta_find_ibss(sdata);
821 break;
822 case IEEE80211_IBSS_MLME_JOINED:
823 ieee80211_sta_merge_ibss(sdata);
824 break;
825 default:
826 WARN_ON(1);
827 break;
828 }
829
830 out:
831 mutex_unlock(&ifibss->mtx);
832 }
833
ieee80211_ibss_timer(unsigned long data)834 static void ieee80211_ibss_timer(unsigned long data)
835 {
836 struct ieee80211_sub_if_data *sdata =
837 (struct ieee80211_sub_if_data *) data;
838 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
839 struct ieee80211_local *local = sdata->local;
840
841 if (local->quiescing) {
842 ifibss->timer_running = true;
843 return;
844 }
845
846 ieee80211_queue_work(&local->hw, &sdata->work);
847 }
848
849 #ifdef CONFIG_PM
ieee80211_ibss_quiesce(struct ieee80211_sub_if_data * sdata)850 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata)
851 {
852 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
853
854 if (del_timer_sync(&ifibss->timer))
855 ifibss->timer_running = true;
856 }
857
ieee80211_ibss_restart(struct ieee80211_sub_if_data * sdata)858 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata)
859 {
860 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
861
862 if (ifibss->timer_running) {
863 add_timer(&ifibss->timer);
864 ifibss->timer_running = false;
865 }
866 }
867 #endif
868
ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data * sdata)869 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
870 {
871 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
872
873 setup_timer(&ifibss->timer, ieee80211_ibss_timer,
874 (unsigned long) sdata);
875 mutex_init(&ifibss->mtx);
876 }
877
878 /* scan finished notification */
ieee80211_ibss_notify_scan_completed(struct ieee80211_local * local)879 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
880 {
881 struct ieee80211_sub_if_data *sdata;
882
883 mutex_lock(&local->iflist_mtx);
884 list_for_each_entry(sdata, &local->interfaces, list) {
885 if (!ieee80211_sdata_running(sdata))
886 continue;
887 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
888 continue;
889 sdata->u.ibss.last_scan_completed = jiffies;
890 ieee80211_queue_work(&local->hw, &sdata->work);
891 }
892 mutex_unlock(&local->iflist_mtx);
893 }
894
ieee80211_ibss_join(struct ieee80211_sub_if_data * sdata,struct cfg80211_ibss_params * params)895 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
896 struct cfg80211_ibss_params *params)
897 {
898 struct sk_buff *skb;
899
900 skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
901 36 /* bitrates */ +
902 34 /* SSID */ +
903 3 /* DS params */ +
904 4 /* IBSS params */ +
905 params->ie_len);
906 if (!skb)
907 return -ENOMEM;
908
909 mutex_lock(&sdata->u.ibss.mtx);
910
911 if (params->bssid) {
912 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
913 sdata->u.ibss.fixed_bssid = true;
914 } else
915 sdata->u.ibss.fixed_bssid = false;
916
917 sdata->u.ibss.privacy = params->privacy;
918 sdata->u.ibss.basic_rates = params->basic_rates;
919 memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate,
920 sizeof(params->mcast_rate));
921
922 sdata->vif.bss_conf.beacon_int = params->beacon_interval;
923
924 sdata->u.ibss.channel = params->channel;
925 sdata->u.ibss.fixed_channel = params->channel_fixed;
926
927 /* fix ourselves to that channel now already */
928 if (params->channel_fixed) {
929 sdata->local->oper_channel = params->channel;
930 WARN_ON(!ieee80211_set_channel_type(sdata->local, sdata,
931 NL80211_CHAN_NO_HT));
932 }
933
934 if (params->ie) {
935 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
936 GFP_KERNEL);
937 if (sdata->u.ibss.ie)
938 sdata->u.ibss.ie_len = params->ie_len;
939 }
940
941 sdata->u.ibss.skb = skb;
942 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
943 sdata->u.ibss.ibss_join_req = jiffies;
944
945 memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);
946 sdata->u.ibss.ssid_len = params->ssid_len;
947
948 mutex_unlock(&sdata->u.ibss.mtx);
949
950 mutex_lock(&sdata->local->mtx);
951 ieee80211_recalc_idle(sdata->local);
952 mutex_unlock(&sdata->local->mtx);
953
954 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
955
956 return 0;
957 }
958
ieee80211_ibss_leave(struct ieee80211_sub_if_data * sdata)959 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
960 {
961 struct sk_buff *skb;
962 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
963 struct ieee80211_local *local = sdata->local;
964 struct cfg80211_bss *cbss;
965 u16 capability;
966 int active_ibss;
967
968 mutex_lock(&sdata->u.ibss.mtx);
969
970 active_ibss = ieee80211_sta_active_ibss(sdata);
971
972 if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) {
973 capability = WLAN_CAPABILITY_IBSS;
974
975 if (ifibss->privacy)
976 capability |= WLAN_CAPABILITY_PRIVACY;
977
978 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->channel,
979 ifibss->bssid, ifibss->ssid,
980 ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
981 WLAN_CAPABILITY_PRIVACY,
982 capability);
983
984 if (cbss) {
985 cfg80211_unlink_bss(local->hw.wiphy, cbss);
986 cfg80211_put_bss(cbss);
987 }
988 }
989
990 sta_info_flush(sdata->local, sdata);
991
992 /* remove beacon */
993 kfree(sdata->u.ibss.ie);
994 skb = sdata->u.ibss.presp;
995 rcu_assign_pointer(sdata->u.ibss.presp, NULL);
996 sdata->vif.bss_conf.ibss_joined = false;
997 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
998 BSS_CHANGED_IBSS);
999 synchronize_rcu();
1000 kfree_skb(skb);
1001
1002 skb_queue_purge(&sdata->skb_queue);
1003 memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
1004 sdata->u.ibss.ssid_len = 0;
1005
1006 del_timer_sync(&sdata->u.ibss.timer);
1007
1008 mutex_unlock(&sdata->u.ibss.mtx);
1009
1010 mutex_lock(&local->mtx);
1011 ieee80211_recalc_idle(sdata->local);
1012 mutex_unlock(&local->mtx);
1013
1014 return 0;
1015 }
1016