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libceph: WARN, don't BUG on unexpected connection states
[deliverable/linux.git] / net / mac80211 / ibss.c
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
24 #include "ieee80211_i.h"
25 #include "driver-ops.h"
26 #include "rate.h"
27
28 #define IEEE80211_SCAN_INTERVAL (2 * HZ)
29 #define IEEE80211_SCAN_INTERVAL_SLOW (15 * HZ)
30 #define IEEE80211_IBSS_JOIN_TIMEOUT (7 * HZ)
31
32 #define IEEE80211_IBSS_MERGE_INTERVAL (30 * HZ)
33 #define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)
34
35 #define IEEE80211_IBSS_MAX_STA_ENTRIES 128
36
37
38 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
39 const u8 *bssid, const int beacon_int,
40 struct ieee80211_channel *chan,
41 const u32 basic_rates,
42 const u16 capability, u64 tsf)
43 {
44 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
45 struct ieee80211_local *local = sdata->local;
46 int rates, i;
47 struct sk_buff *skb;
48 struct ieee80211_mgmt *mgmt;
49 u8 *pos;
50 struct ieee80211_supported_band *sband;
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
56 lockdep_assert_held(&ifibss->mtx);
57
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 synchronize_rcu();
64 skb->data = skb->head;
65 skb->len = 0;
66 skb_reset_tail_pointer(skb);
67 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 /* if merging, indicate to driver that we leave the old IBSS */
73 if (sdata->vif.bss_conf.ibss_joined) {
74 sdata->vif.bss_conf.ibss_joined = false;
75 netif_carrier_off(sdata->dev);
76 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_IBSS);
77 }
78
79 memcpy(ifibss->bssid, bssid, ETH_ALEN);
80
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 channel_type = NL80211_CHAN_HT20;
87 if (!ieee80211_set_channel_type(local, sdata, channel_type)) {
88 /* can only fail due to HT40+/- mismatch */
89 channel_type = NL80211_CHAN_HT20;
90 WARN_ON(!ieee80211_set_channel_type(local, sdata,
91 NL80211_CHAN_HT20));
92 }
93 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
94
95 sband = local->hw.wiphy->bands[chan->band];
96
97 /* build supported rates array */
98 pos = supp_rates;
99 for (i = 0; i < sband->n_bitrates; i++) {
100 int rate = sband->bitrates[i].bitrate;
101 u8 basic = 0;
102 if (basic_rates & BIT(i))
103 basic = 0x80;
104 *pos++ = basic | (u8) (rate / 5);
105 }
106
107 /* Build IBSS probe response */
108 mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon));
109 memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
110 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
111 IEEE80211_STYPE_PROBE_RESP);
112 memset(mgmt->da, 0xff, ETH_ALEN);
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 mgmt->u.beacon.capab_info = cpu_to_le16(capability);
118
119 pos = skb_put(skb, 2 + ifibss->ssid_len);
120 *pos++ = WLAN_EID_SSID;
121 *pos++ = ifibss->ssid_len;
122 memcpy(pos, ifibss->ssid, ifibss->ssid_len);
123
124 rates = sband->n_bitrates;
125 if (rates > 8)
126 rates = 8;
127 pos = skb_put(skb, 2 + rates);
128 *pos++ = WLAN_EID_SUPP_RATES;
129 *pos++ = rates;
130 memcpy(pos, supp_rates, rates);
131
132 if (sband->band == IEEE80211_BAND_2GHZ) {
133 pos = skb_put(skb, 2 + 1);
134 *pos++ = WLAN_EID_DS_PARAMS;
135 *pos++ = 1;
136 *pos++ = ieee80211_frequency_to_channel(chan->center_freq);
137 }
138
139 pos = skb_put(skb, 2 + 2);
140 *pos++ = WLAN_EID_IBSS_PARAMS;
141 *pos++ = 2;
142 /* FIX: set ATIM window based on scan results */
143 *pos++ = 0;
144 *pos++ = 0;
145
146 if (sband->n_bitrates > 8) {
147 rates = sband->n_bitrates - 8;
148 pos = skb_put(skb, 2 + rates);
149 *pos++ = WLAN_EID_EXT_SUPP_RATES;
150 *pos++ = rates;
151 memcpy(pos, &supp_rates[8], rates);
152 }
153
154 if (ifibss->ie_len)
155 memcpy(skb_put(skb, ifibss->ie_len),
156 ifibss->ie, ifibss->ie_len);
157
158 /* add HT capability and information IEs */
159 if (channel_type && sband->ht_cap.ht_supported) {
160 pos = skb_put(skb, 4 +
161 sizeof(struct ieee80211_ht_cap) +
162 sizeof(struct ieee80211_ht_operation));
163 pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap,
164 sband->ht_cap.cap);
165 /*
166 * Note: According to 802.11n-2009 9.13.3.1, HT Protection
167 * field and RIFS Mode are reserved in IBSS mode, therefore
168 * keep them at 0
169 */
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 pos = skb_put(skb, 9);
176 *pos++ = WLAN_EID_VENDOR_SPECIFIC;
177 *pos++ = 7; /* len */
178 *pos++ = 0x00; /* Microsoft OUI 00:50:F2 */
179 *pos++ = 0x50;
180 *pos++ = 0xf2;
181 *pos++ = 2; /* WME */
182 *pos++ = 0; /* WME info */
183 *pos++ = 1; /* WME ver */
184 *pos++ = 0; /* U-APSD no in use */
185 }
186
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 bss_change = BSS_CHANGED_BEACON_INT;
192 bss_change |= ieee80211_reset_erp_info(sdata);
193 bss_change |= BSS_CHANGED_BSSID;
194 bss_change |= BSS_CHANGED_BEACON;
195 bss_change |= BSS_CHANGED_BEACON_ENABLED;
196 bss_change |= BSS_CHANGED_BASIC_RATES;
197 bss_change |= BSS_CHANGED_HT;
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 netif_carrier_on(sdata->dev);
212 cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
213 }
214
215 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
216 struct ieee80211_bss *bss)
217 {
218 struct cfg80211_bss *cbss =
219 container_of((void *)bss, struct cfg80211_bss, priv);
220 struct ieee80211_supported_band *sband;
221 u32 basic_rates;
222 int i, j;
223 u16 beacon_int = cbss->beacon_interval;
224
225 lockdep_assert_held(&sdata->u.ibss.mtx);
226
227 if (beacon_int < 10)
228 beacon_int = 10;
229
230 sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
231
232 basic_rates = 0;
233
234 for (i = 0; i < bss->supp_rates_len; i++) {
235 int rate = (bss->supp_rates[i] & 0x7f) * 5;
236 bool is_basic = !!(bss->supp_rates[i] & 0x80);
237
238 for (j = 0; j < sband->n_bitrates; j++) {
239 if (sband->bitrates[j].bitrate == rate) {
240 if (is_basic)
241 basic_rates |= BIT(j);
242 break;
243 }
244 }
245 }
246
247 __ieee80211_sta_join_ibss(sdata, cbss->bssid,
248 beacon_int,
249 cbss->channel,
250 basic_rates,
251 cbss->capability,
252 cbss->tsf);
253 }
254
255 static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta,
256 bool auth)
257 __acquires(RCU)
258 {
259 struct ieee80211_sub_if_data *sdata = sta->sdata;
260 u8 addr[ETH_ALEN];
261
262 memcpy(addr, sta->sta.addr, ETH_ALEN);
263
264 ibss_dbg(sdata, "Adding new IBSS station %pM\n", addr);
265
266 sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
267 sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
268 /* authorize the station only if the network is not RSN protected. If
269 * not wait for the userspace to authorize it */
270 if (!sta->sdata->u.ibss.control_port)
271 sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
272
273 rate_control_rate_init(sta);
274
275 /* If it fails, maybe we raced another insertion? */
276 if (sta_info_insert_rcu(sta))
277 return sta_info_get(sdata, addr);
278 if (auth && !sdata->u.ibss.auth_frame_registrations) {
279 ibss_dbg(sdata,
280 "TX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=1)\n",
281 sdata->vif.addr, sdata->u.ibss.bssid, addr);
282 ieee80211_send_auth(sdata, 1, WLAN_AUTH_OPEN, NULL, 0,
283 addr, sdata->u.ibss.bssid, NULL, 0, 0);
284 }
285 return sta;
286 }
287
288 static struct sta_info *
289 ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
290 const u8 *bssid, const u8 *addr,
291 u32 supp_rates, bool auth)
292 __acquires(RCU)
293 {
294 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
295 struct ieee80211_local *local = sdata->local;
296 struct sta_info *sta;
297 int band = local->hw.conf.channel->band;
298
299 /*
300 * XXX: Consider removing the least recently used entry and
301 * allow new one to be added.
302 */
303 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
304 net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
305 sdata->name, addr);
306 rcu_read_lock();
307 return NULL;
308 }
309
310 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH) {
311 rcu_read_lock();
312 return NULL;
313 }
314
315 if (!ether_addr_equal(bssid, sdata->u.ibss.bssid)) {
316 rcu_read_lock();
317 return NULL;
318 }
319
320 sta = sta_info_alloc(sdata, addr, GFP_KERNEL);
321 if (!sta) {
322 rcu_read_lock();
323 return NULL;
324 }
325
326 sta->last_rx = jiffies;
327
328 /* make sure mandatory rates are always added */
329 sta->sta.supp_rates[band] = supp_rates |
330 ieee80211_mandatory_rates(local, band);
331
332 return ieee80211_ibss_finish_sta(sta, auth);
333 }
334
335 static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata,
336 struct ieee80211_mgmt *mgmt,
337 size_t len)
338 {
339 u16 auth_alg, auth_transaction;
340
341 lockdep_assert_held(&sdata->u.ibss.mtx);
342
343 if (len < 24 + 6)
344 return;
345
346 auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
347 auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
348
349 if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1)
350 return;
351 ibss_dbg(sdata,
352 "RX Auth SA=%pM DA=%pM BSSID=%pM (auth_transaction=%d)\n",
353 mgmt->sa, mgmt->da, mgmt->bssid, auth_transaction);
354 sta_info_destroy_addr(sdata, mgmt->sa);
355 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, 0, false);
356 rcu_read_unlock();
357
358 /*
359 * IEEE 802.11 standard does not require authentication in IBSS
360 * networks and most implementations do not seem to use it.
361 * However, try to reply to authentication attempts if someone
362 * has actually implemented this.
363 */
364 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0,
365 mgmt->sa, sdata->u.ibss.bssid, NULL, 0, 0);
366 }
367
368 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
369 struct ieee80211_mgmt *mgmt,
370 size_t len,
371 struct ieee80211_rx_status *rx_status,
372 struct ieee802_11_elems *elems,
373 bool beacon)
374 {
375 struct ieee80211_local *local = sdata->local;
376 int freq;
377 struct cfg80211_bss *cbss;
378 struct ieee80211_bss *bss;
379 struct sta_info *sta;
380 struct ieee80211_channel *channel;
381 u64 beacon_timestamp, rx_timestamp;
382 u32 supp_rates = 0;
383 enum ieee80211_band band = rx_status->band;
384 struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
385 bool rates_updated = false;
386
387 if (elems->ds_params && elems->ds_params_len == 1)
388 freq = ieee80211_channel_to_frequency(elems->ds_params[0],
389 band);
390 else
391 freq = rx_status->freq;
392
393 channel = ieee80211_get_channel(local->hw.wiphy, freq);
394
395 if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
396 return;
397
398 if (sdata->vif.type == NL80211_IFTYPE_ADHOC &&
399 ether_addr_equal(mgmt->bssid, sdata->u.ibss.bssid)) {
400
401 rcu_read_lock();
402 sta = sta_info_get(sdata, mgmt->sa);
403
404 if (elems->supp_rates) {
405 supp_rates = ieee80211_sta_get_rates(local, elems,
406 band, NULL);
407 if (sta) {
408 u32 prev_rates;
409
410 prev_rates = sta->sta.supp_rates[band];
411 /* make sure mandatory rates are always added */
412 sta->sta.supp_rates[band] = supp_rates |
413 ieee80211_mandatory_rates(local, band);
414
415 if (sta->sta.supp_rates[band] != prev_rates) {
416 ibss_dbg(sdata,
417 "updated supp_rates set for %pM based on beacon/probe_resp (0x%x -> 0x%x)\n",
418 sta->sta.addr, prev_rates,
419 sta->sta.supp_rates[band]);
420 rates_updated = true;
421 }
422 } else {
423 rcu_read_unlock();
424 sta = ieee80211_ibss_add_sta(sdata, mgmt->bssid,
425 mgmt->sa, supp_rates, true);
426 }
427 }
428
429 if (sta && elems->wmm_info)
430 set_sta_flag(sta, WLAN_STA_WME);
431
432 if (sta && elems->ht_operation && elems->ht_cap_elem &&
433 sdata->u.ibss.channel_type != NL80211_CHAN_NO_HT) {
434 /* we both use HT */
435 struct ieee80211_sta_ht_cap sta_ht_cap_new;
436 enum nl80211_channel_type channel_type =
437 ieee80211_ht_oper_to_channel_type(
438 elems->ht_operation);
439
440 ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
441 elems->ht_cap_elem,
442 &sta_ht_cap_new);
443
444 /*
445 * fall back to HT20 if we don't use or use
446 * the other extension channel
447 */
448 if (!(channel_type == NL80211_CHAN_HT40MINUS ||
449 channel_type == NL80211_CHAN_HT40PLUS) ||
450 channel_type != sdata->u.ibss.channel_type)
451 sta_ht_cap_new.cap &=
452 ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
453
454 if (memcmp(&sta->sta.ht_cap, &sta_ht_cap_new,
455 sizeof(sta_ht_cap_new))) {
456 memcpy(&sta->sta.ht_cap, &sta_ht_cap_new,
457 sizeof(sta_ht_cap_new));
458 rates_updated = true;
459 }
460 }
461
462 if (sta && rates_updated)
463 rate_control_rate_init(sta);
464
465 rcu_read_unlock();
466 }
467
468 bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
469 channel, beacon);
470 if (!bss)
471 return;
472
473 cbss = container_of((void *)bss, struct cfg80211_bss, priv);
474
475 /* was just updated in ieee80211_bss_info_update */
476 beacon_timestamp = cbss->tsf;
477
478 /* check if we need to merge IBSS */
479
480 /* we use a fixed BSSID */
481 if (sdata->u.ibss.fixed_bssid)
482 goto put_bss;
483
484 /* not an IBSS */
485 if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
486 goto put_bss;
487
488 /* different channel */
489 if (cbss->channel != local->oper_channel)
490 goto put_bss;
491
492 /* different SSID */
493 if (elems->ssid_len != sdata->u.ibss.ssid_len ||
494 memcmp(elems->ssid, sdata->u.ibss.ssid,
495 sdata->u.ibss.ssid_len))
496 goto put_bss;
497
498 /* same BSSID */
499 if (ether_addr_equal(cbss->bssid, sdata->u.ibss.bssid))
500 goto put_bss;
501
502 if (rx_status->flag & RX_FLAG_MACTIME_MPDU) {
503 /*
504 * For correct IBSS merging we need mactime; since mactime is
505 * defined as the time the first data symbol of the frame hits
506 * the PHY, and the timestamp of the beacon is defined as "the
507 * time that the data symbol containing the first bit of the
508 * timestamp is transmitted to the PHY plus the transmitting
509 * STA's delays through its local PHY from the MAC-PHY
510 * interface to its interface with the WM" (802.11 11.1.2)
511 * - equals the time this bit arrives at the receiver - we have
512 * to take into account the offset between the two.
513 *
514 * E.g. at 1 MBit that means mactime is 192 usec earlier
515 * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
516 */
517 int rate;
518
519 if (rx_status->flag & RX_FLAG_HT)
520 rate = 65; /* TODO: HT rates */
521 else
522 rate = local->hw.wiphy->bands[band]->
523 bitrates[rx_status->rate_idx].bitrate;
524
525 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
526 } else {
527 /*
528 * second best option: get current TSF
529 * (will return -1 if not supported)
530 */
531 rx_timestamp = drv_get_tsf(local, sdata);
532 }
533
534 ibss_dbg(sdata,
535 "RX beacon SA=%pM BSSID=%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
536 mgmt->sa, mgmt->bssid,
537 (unsigned long long)rx_timestamp,
538 (unsigned long long)beacon_timestamp,
539 (unsigned long long)(rx_timestamp - beacon_timestamp),
540 jiffies);
541
542 if (beacon_timestamp > rx_timestamp) {
543 ibss_dbg(sdata,
544 "beacon TSF higher than local TSF - IBSS merge with BSSID %pM\n",
545 mgmt->bssid);
546 ieee80211_sta_join_ibss(sdata, bss);
547 supp_rates = ieee80211_sta_get_rates(local, elems, band, NULL);
548 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
549 supp_rates, true);
550 rcu_read_unlock();
551 }
552
553 put_bss:
554 ieee80211_rx_bss_put(local, bss);
555 }
556
557 void ieee80211_ibss_rx_no_sta(struct ieee80211_sub_if_data *sdata,
558 const u8 *bssid, const u8 *addr,
559 u32 supp_rates)
560 {
561 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
562 struct ieee80211_local *local = sdata->local;
563 struct sta_info *sta;
564 int band = local->hw.conf.channel->band;
565
566 /*
567 * XXX: Consider removing the least recently used entry and
568 * allow new one to be added.
569 */
570 if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
571 net_info_ratelimited("%s: No room for a new IBSS STA entry %pM\n",
572 sdata->name, addr);
573 return;
574 }
575
576 if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
577 return;
578
579 if (!ether_addr_equal(bssid, sdata->u.ibss.bssid))
580 return;
581
582 sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
583 if (!sta)
584 return;
585
586 sta->last_rx = jiffies;
587
588 /* make sure mandatory rates are always added */
589 sta->sta.supp_rates[band] = supp_rates |
590 ieee80211_mandatory_rates(local, band);
591
592 spin_lock(&ifibss->incomplete_lock);
593 list_add(&sta->list, &ifibss->incomplete_stations);
594 spin_unlock(&ifibss->incomplete_lock);
595 ieee80211_queue_work(&local->hw, &sdata->work);
596 }
597
598 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
599 {
600 struct ieee80211_local *local = sdata->local;
601 int active = 0;
602 struct sta_info *sta;
603
604 lockdep_assert_held(&sdata->u.ibss.mtx);
605
606 rcu_read_lock();
607
608 list_for_each_entry_rcu(sta, &local->sta_list, list) {
609 if (sta->sdata == sdata &&
610 time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
611 jiffies)) {
612 active++;
613 break;
614 }
615 }
616
617 rcu_read_unlock();
618
619 return active;
620 }
621
622 /*
623 * This function is called with state == IEEE80211_IBSS_MLME_JOINED
624 */
625
626 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
627 {
628 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
629
630 lockdep_assert_held(&ifibss->mtx);
631
632 mod_timer(&ifibss->timer,
633 round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
634
635 ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
636
637 if (time_before(jiffies, ifibss->last_scan_completed +
638 IEEE80211_IBSS_MERGE_INTERVAL))
639 return;
640
641 if (ieee80211_sta_active_ibss(sdata))
642 return;
643
644 if (ifibss->fixed_channel)
645 return;
646
647 sdata_info(sdata,
648 "No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)\n");
649
650 ieee80211_request_internal_scan(sdata,
651 ifibss->ssid, ifibss->ssid_len, NULL);
652 }
653
654 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
655 {
656 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
657 u8 bssid[ETH_ALEN];
658 u16 capability;
659 int i;
660
661 lockdep_assert_held(&ifibss->mtx);
662
663 if (ifibss->fixed_bssid) {
664 memcpy(bssid, ifibss->bssid, ETH_ALEN);
665 } else {
666 /* Generate random, not broadcast, locally administered BSSID. Mix in
667 * own MAC address to make sure that devices that do not have proper
668 * random number generator get different BSSID. */
669 get_random_bytes(bssid, ETH_ALEN);
670 for (i = 0; i < ETH_ALEN; i++)
671 bssid[i] ^= sdata->vif.addr[i];
672 bssid[0] &= ~0x01;
673 bssid[0] |= 0x02;
674 }
675
676 sdata_info(sdata, "Creating new IBSS network, BSSID %pM\n", bssid);
677
678 capability = WLAN_CAPABILITY_IBSS;
679
680 if (ifibss->privacy)
681 capability |= WLAN_CAPABILITY_PRIVACY;
682 else
683 sdata->drop_unencrypted = 0;
684
685 __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
686 ifibss->channel, ifibss->basic_rates,
687 capability, 0);
688 }
689
690 /*
691 * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
692 */
693
694 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
695 {
696 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
697 struct ieee80211_local *local = sdata->local;
698 struct cfg80211_bss *cbss;
699 struct ieee80211_channel *chan = NULL;
700 const u8 *bssid = NULL;
701 int active_ibss;
702 u16 capability;
703
704 lockdep_assert_held(&ifibss->mtx);
705
706 active_ibss = ieee80211_sta_active_ibss(sdata);
707 ibss_dbg(sdata, "sta_find_ibss (active_ibss=%d)\n", active_ibss);
708
709 if (active_ibss)
710 return;
711
712 capability = WLAN_CAPABILITY_IBSS;
713 if (ifibss->privacy)
714 capability |= WLAN_CAPABILITY_PRIVACY;
715 if (ifibss->fixed_bssid)
716 bssid = ifibss->bssid;
717 if (ifibss->fixed_channel)
718 chan = ifibss->channel;
719 if (!is_zero_ether_addr(ifibss->bssid))
720 bssid = ifibss->bssid;
721 cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
722 ifibss->ssid, ifibss->ssid_len,
723 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
724 capability);
725
726 if (cbss) {
727 struct ieee80211_bss *bss;
728
729 bss = (void *)cbss->priv;
730 ibss_dbg(sdata,
731 "sta_find_ibss: selected %pM current %pM\n",
732 cbss->bssid, ifibss->bssid);
733 sdata_info(sdata,
734 "Selected IBSS BSSID %pM based on configured SSID\n",
735 cbss->bssid);
736
737 ieee80211_sta_join_ibss(sdata, bss);
738 ieee80211_rx_bss_put(local, bss);
739 return;
740 }
741
742 ibss_dbg(sdata, "sta_find_ibss: did not try to join ibss\n");
743
744 /* Selected IBSS not found in current scan results - try to scan */
745 if (time_after(jiffies, ifibss->last_scan_completed +
746 IEEE80211_SCAN_INTERVAL)) {
747 sdata_info(sdata, "Trigger new scan to find an IBSS to join\n");
748
749 ieee80211_request_internal_scan(sdata,
750 ifibss->ssid, ifibss->ssid_len,
751 ifibss->fixed_channel ? ifibss->channel : NULL);
752 } else {
753 int interval = IEEE80211_SCAN_INTERVAL;
754
755 if (time_after(jiffies, ifibss->ibss_join_req +
756 IEEE80211_IBSS_JOIN_TIMEOUT)) {
757 if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
758 ieee80211_sta_create_ibss(sdata);
759 return;
760 }
761 sdata_info(sdata, "IBSS not allowed on %d MHz\n",
762 local->hw.conf.channel->center_freq);
763
764 /* No IBSS found - decrease scan interval and continue
765 * scanning. */
766 interval = IEEE80211_SCAN_INTERVAL_SLOW;
767 }
768
769 mod_timer(&ifibss->timer,
770 round_jiffies(jiffies + interval));
771 }
772 }
773
774 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
775 struct sk_buff *req)
776 {
777 struct ieee80211_mgmt *mgmt = (void *)req->data;
778 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
779 struct ieee80211_local *local = sdata->local;
780 int tx_last_beacon, len = req->len;
781 struct sk_buff *skb;
782 struct ieee80211_mgmt *resp;
783 struct sk_buff *presp;
784 u8 *pos, *end;
785
786 lockdep_assert_held(&ifibss->mtx);
787
788 presp = rcu_dereference_protected(ifibss->presp,
789 lockdep_is_held(&ifibss->mtx));
790
791 if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
792 len < 24 + 2 || !presp)
793 return;
794
795 tx_last_beacon = drv_tx_last_beacon(local);
796
797 ibss_dbg(sdata,
798 "RX ProbeReq SA=%pM DA=%pM BSSID=%pM (tx_last_beacon=%d)\n",
799 mgmt->sa, mgmt->da, mgmt->bssid, tx_last_beacon);
800
801 if (!tx_last_beacon && is_multicast_ether_addr(mgmt->da))
802 return;
803
804 if (!ether_addr_equal(mgmt->bssid, ifibss->bssid) &&
805 !is_broadcast_ether_addr(mgmt->bssid))
806 return;
807
808 end = ((u8 *) mgmt) + len;
809 pos = mgmt->u.probe_req.variable;
810 if (pos[0] != WLAN_EID_SSID ||
811 pos + 2 + pos[1] > end) {
812 ibss_dbg(sdata, "Invalid SSID IE in ProbeReq from %pM\n",
813 mgmt->sa);
814 return;
815 }
816 if (pos[1] != 0 &&
817 (pos[1] != ifibss->ssid_len ||
818 memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
819 /* Ignore ProbeReq for foreign SSID */
820 return;
821 }
822
823 /* Reply with ProbeResp */
824 skb = skb_copy(presp, GFP_KERNEL);
825 if (!skb)
826 return;
827
828 resp = (struct ieee80211_mgmt *) skb->data;
829 memcpy(resp->da, mgmt->sa, ETH_ALEN);
830 ibss_dbg(sdata, "Sending ProbeResp to %pM\n", resp->da);
831 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
832 ieee80211_tx_skb(sdata, skb);
833 }
834
835 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
836 struct ieee80211_mgmt *mgmt,
837 size_t len,
838 struct ieee80211_rx_status *rx_status)
839 {
840 size_t baselen;
841 struct ieee802_11_elems elems;
842
843 baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
844 if (baselen > len)
845 return;
846
847 ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
848 &elems);
849
850 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
851 }
852
853 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
854 struct ieee80211_mgmt *mgmt,
855 size_t len,
856 struct ieee80211_rx_status *rx_status)
857 {
858 size_t baselen;
859 struct ieee802_11_elems elems;
860
861 /* Process beacon from the current BSS */
862 baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
863 if (baselen > len)
864 return;
865
866 ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
867
868 ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
869 }
870
871 void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
872 struct sk_buff *skb)
873 {
874 struct ieee80211_rx_status *rx_status;
875 struct ieee80211_mgmt *mgmt;
876 u16 fc;
877
878 rx_status = IEEE80211_SKB_RXCB(skb);
879 mgmt = (struct ieee80211_mgmt *) skb->data;
880 fc = le16_to_cpu(mgmt->frame_control);
881
882 mutex_lock(&sdata->u.ibss.mtx);
883
884 if (!sdata->u.ibss.ssid_len)
885 goto mgmt_out; /* not ready to merge yet */
886
887 switch (fc & IEEE80211_FCTL_STYPE) {
888 case IEEE80211_STYPE_PROBE_REQ:
889 ieee80211_rx_mgmt_probe_req(sdata, skb);
890 break;
891 case IEEE80211_STYPE_PROBE_RESP:
892 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
893 rx_status);
894 break;
895 case IEEE80211_STYPE_BEACON:
896 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
897 rx_status);
898 break;
899 case IEEE80211_STYPE_AUTH:
900 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
901 break;
902 }
903
904 mgmt_out:
905 mutex_unlock(&sdata->u.ibss.mtx);
906 }
907
908 void ieee80211_ibss_work(struct ieee80211_sub_if_data *sdata)
909 {
910 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
911 struct sta_info *sta;
912
913 mutex_lock(&ifibss->mtx);
914
915 /*
916 * Work could be scheduled after scan or similar
917 * when we aren't even joined (or trying) with a
918 * network.
919 */
920 if (!ifibss->ssid_len)
921 goto out;
922
923 spin_lock_bh(&ifibss->incomplete_lock);
924 while (!list_empty(&ifibss->incomplete_stations)) {
925 sta = list_first_entry(&ifibss->incomplete_stations,
926 struct sta_info, list);
927 list_del(&sta->list);
928 spin_unlock_bh(&ifibss->incomplete_lock);
929
930 ieee80211_ibss_finish_sta(sta, true);
931 rcu_read_unlock();
932 spin_lock_bh(&ifibss->incomplete_lock);
933 }
934 spin_unlock_bh(&ifibss->incomplete_lock);
935
936 switch (ifibss->state) {
937 case IEEE80211_IBSS_MLME_SEARCH:
938 ieee80211_sta_find_ibss(sdata);
939 break;
940 case IEEE80211_IBSS_MLME_JOINED:
941 ieee80211_sta_merge_ibss(sdata);
942 break;
943 default:
944 WARN_ON(1);
945 break;
946 }
947
948 out:
949 mutex_unlock(&ifibss->mtx);
950 }
951
952 static void ieee80211_ibss_timer(unsigned long data)
953 {
954 struct ieee80211_sub_if_data *sdata =
955 (struct ieee80211_sub_if_data *) data;
956 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
957 struct ieee80211_local *local = sdata->local;
958
959 if (local->quiescing) {
960 ifibss->timer_running = true;
961 return;
962 }
963
964 ieee80211_queue_work(&local->hw, &sdata->work);
965 }
966
967 #ifdef CONFIG_PM
968 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata)
969 {
970 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
971
972 if (del_timer_sync(&ifibss->timer))
973 ifibss->timer_running = true;
974 }
975
976 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata)
977 {
978 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
979
980 if (ifibss->timer_running) {
981 add_timer(&ifibss->timer);
982 ifibss->timer_running = false;
983 }
984 }
985 #endif
986
987 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
988 {
989 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
990
991 setup_timer(&ifibss->timer, ieee80211_ibss_timer,
992 (unsigned long) sdata);
993 mutex_init(&ifibss->mtx);
994 INIT_LIST_HEAD(&ifibss->incomplete_stations);
995 spin_lock_init(&ifibss->incomplete_lock);
996 }
997
998 /* scan finished notification */
999 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
1000 {
1001 struct ieee80211_sub_if_data *sdata;
1002
1003 mutex_lock(&local->iflist_mtx);
1004 list_for_each_entry(sdata, &local->interfaces, list) {
1005 if (!ieee80211_sdata_running(sdata))
1006 continue;
1007 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
1008 continue;
1009 sdata->u.ibss.last_scan_completed = jiffies;
1010 ieee80211_queue_work(&local->hw, &sdata->work);
1011 }
1012 mutex_unlock(&local->iflist_mtx);
1013 }
1014
1015 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
1016 struct cfg80211_ibss_params *params)
1017 {
1018 struct sk_buff *skb;
1019 u32 changed = 0;
1020
1021 skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
1022 sizeof(struct ieee80211_hdr_3addr) +
1023 12 /* struct ieee80211_mgmt.u.beacon */ +
1024 2 + IEEE80211_MAX_SSID_LEN /* max SSID */ +
1025 2 + 8 /* max Supported Rates */ +
1026 3 /* max DS params */ +
1027 4 /* IBSS params */ +
1028 2 + (IEEE80211_MAX_SUPP_RATES - 8) +
1029 2 + sizeof(struct ieee80211_ht_cap) +
1030 2 + sizeof(struct ieee80211_ht_operation) +
1031 params->ie_len);
1032 if (!skb)
1033 return -ENOMEM;
1034
1035 mutex_lock(&sdata->u.ibss.mtx);
1036
1037 if (params->bssid) {
1038 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
1039 sdata->u.ibss.fixed_bssid = true;
1040 } else
1041 sdata->u.ibss.fixed_bssid = false;
1042
1043 sdata->u.ibss.privacy = params->privacy;
1044 sdata->u.ibss.control_port = params->control_port;
1045 sdata->u.ibss.basic_rates = params->basic_rates;
1046 memcpy(sdata->vif.bss_conf.mcast_rate, params->mcast_rate,
1047 sizeof(params->mcast_rate));
1048
1049 sdata->vif.bss_conf.beacon_int = params->beacon_interval;
1050
1051 sdata->u.ibss.channel = params->channel;
1052 sdata->u.ibss.channel_type = params->channel_type;
1053 sdata->u.ibss.fixed_channel = params->channel_fixed;
1054
1055 /* fix ourselves to that channel now already */
1056 if (params->channel_fixed) {
1057 sdata->local->oper_channel = params->channel;
1058 if (!ieee80211_set_channel_type(sdata->local, sdata,
1059 params->channel_type)) {
1060 mutex_unlock(&sdata->u.ibss.mtx);
1061 kfree_skb(skb);
1062 return -EINVAL;
1063 }
1064 }
1065
1066 if (params->ie) {
1067 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
1068 GFP_KERNEL);
1069 if (sdata->u.ibss.ie)
1070 sdata->u.ibss.ie_len = params->ie_len;
1071 }
1072
1073 sdata->u.ibss.skb = skb;
1074 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
1075 sdata->u.ibss.ibss_join_req = jiffies;
1076
1077 memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);
1078 sdata->u.ibss.ssid_len = params->ssid_len;
1079
1080 mutex_unlock(&sdata->u.ibss.mtx);
1081
1082 mutex_lock(&sdata->local->mtx);
1083 ieee80211_recalc_idle(sdata->local);
1084 mutex_unlock(&sdata->local->mtx);
1085
1086 /*
1087 * 802.11n-2009 9.13.3.1: In an IBSS, the HT Protection field is
1088 * reserved, but an HT STA shall protect HT transmissions as though
1089 * the HT Protection field were set to non-HT mixed mode.
1090 *
1091 * In an IBSS, the RIFS Mode field of the HT Operation element is
1092 * also reserved, but an HT STA shall operate as though this field
1093 * were set to 1.
1094 */
1095
1096 sdata->vif.bss_conf.ht_operation_mode |=
1097 IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED
1098 | IEEE80211_HT_PARAM_RIFS_MODE;
1099
1100 changed |= BSS_CHANGED_HT;
1101 ieee80211_bss_info_change_notify(sdata, changed);
1102
1103 ieee80211_queue_work(&sdata->local->hw, &sdata->work);
1104
1105 return 0;
1106 }
1107
1108 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
1109 {
1110 struct sk_buff *skb;
1111 struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
1112 struct ieee80211_local *local = sdata->local;
1113 struct cfg80211_bss *cbss;
1114 u16 capability;
1115 int active_ibss;
1116 struct sta_info *sta;
1117
1118 mutex_lock(&sdata->u.ibss.mtx);
1119
1120 sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
1121 memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
1122 sdata->u.ibss.ssid_len = 0;
1123
1124 active_ibss = ieee80211_sta_active_ibss(sdata);
1125
1126 if (!active_ibss && !is_zero_ether_addr(ifibss->bssid)) {
1127 capability = WLAN_CAPABILITY_IBSS;
1128
1129 if (ifibss->privacy)
1130 capability |= WLAN_CAPABILITY_PRIVACY;
1131
1132 cbss = cfg80211_get_bss(local->hw.wiphy, ifibss->channel,
1133 ifibss->bssid, ifibss->ssid,
1134 ifibss->ssid_len, WLAN_CAPABILITY_IBSS |
1135 WLAN_CAPABILITY_PRIVACY,
1136 capability);
1137
1138 if (cbss) {
1139 cfg80211_unlink_bss(local->hw.wiphy, cbss);
1140 cfg80211_put_bss(cbss);
1141 }
1142 }
1143
1144 sta_info_flush(sdata->local, sdata);
1145
1146 spin_lock_bh(&ifibss->incomplete_lock);
1147 while (!list_empty(&ifibss->incomplete_stations)) {
1148 sta = list_first_entry(&ifibss->incomplete_stations,
1149 struct sta_info, list);
1150 list_del(&sta->list);
1151 spin_unlock_bh(&ifibss->incomplete_lock);
1152
1153 sta_info_free(local, sta);
1154 spin_lock_bh(&ifibss->incomplete_lock);
1155 }
1156 spin_unlock_bh(&ifibss->incomplete_lock);
1157
1158 netif_carrier_off(sdata->dev);
1159
1160 /* remove beacon */
1161 kfree(sdata->u.ibss.ie);
1162 skb = rcu_dereference_protected(sdata->u.ibss.presp,
1163 lockdep_is_held(&sdata->u.ibss.mtx));
1164 RCU_INIT_POINTER(sdata->u.ibss.presp, NULL);
1165 sdata->vif.bss_conf.ibss_joined = false;
1166 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED |
1167 BSS_CHANGED_IBSS);
1168 synchronize_rcu();
1169 kfree_skb(skb);
1170
1171 skb_queue_purge(&sdata->skb_queue);
1172
1173 del_timer_sync(&sdata->u.ibss.timer);
1174
1175 mutex_unlock(&sdata->u.ibss.mtx);
1176
1177 mutex_lock(&local->mtx);
1178 ieee80211_recalc_idle(sdata->local);
1179 mutex_unlock(&local->mtx);
1180
1181 return 0;
1182 }
Linux kernel - Deliverables
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