Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...
[linux-2.6.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/if_ether.h>
17 #include <linux/skbuff.h>
18 #include <linux/if_arp.h>
19 #include <linux/etherdevice.h>
20 #include <linux/rtnetlink.h>
21 #include <net/mac80211.h>
22 #include <asm/unaligned.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_MERGE_DELAY 0x400000
34 #define IEEE80211_IBSS_INACTIVITY_LIMIT (60 * HZ)
35
36 #define IEEE80211_IBSS_MAX_STA_ENTRIES 128
37
38
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         if (len < 24 + 6)
46                 return;
47
48         auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg);
49         auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction);
50         status_code = le16_to_cpu(mgmt->u.auth.status_code);
51
52         /*
53          * IEEE 802.11 standard does not require authentication in IBSS
54          * networks and most implementations do not seem to use it.
55          * However, try to reply to authentication attempts if someone
56          * has actually implemented this.
57          */
58         if (auth_alg == WLAN_AUTH_OPEN && auth_transaction == 1)
59                 ieee80211_send_auth(sdata, 2, WLAN_AUTH_OPEN, NULL, 0,
60                                     sdata->u.ibss.bssid, NULL, 0, 0);
61 }
62
63 static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
64                                       const u8 *bssid, const int beacon_int,
65                                       struct ieee80211_channel *chan,
66                                       const u32 basic_rates,
67                                       const u16 capability, u64 tsf)
68 {
69         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
70         struct ieee80211_local *local = sdata->local;
71         int rates, i;
72         struct sk_buff *skb;
73         struct ieee80211_mgmt *mgmt;
74         u8 *pos;
75         struct ieee80211_supported_band *sband;
76         struct cfg80211_bss *bss;
77         u32 bss_change;
78         u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
79
80         /* Reset own TSF to allow time synchronization work. */
81         drv_reset_tsf(local);
82
83         skb = ifibss->skb;
84         rcu_assign_pointer(ifibss->presp, NULL);
85         synchronize_rcu();
86         skb->data = skb->head;
87         skb->len = 0;
88         skb_reset_tail_pointer(skb);
89         skb_reserve(skb, sdata->local->hw.extra_tx_headroom);
90
91         if (memcmp(ifibss->bssid, bssid, ETH_ALEN))
92                 sta_info_flush(sdata->local, sdata);
93
94         memcpy(ifibss->bssid, bssid, ETH_ALEN);
95
96         sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
97
98         local->oper_channel = chan;
99         local->oper_channel_type = NL80211_CHAN_NO_HT;
100         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
101
102         sband = local->hw.wiphy->bands[chan->band];
103
104         /* build supported rates array */
105         pos = supp_rates;
106         for (i = 0; i < sband->n_bitrates; i++) {
107                 int rate = sband->bitrates[i].bitrate;
108                 u8 basic = 0;
109                 if (basic_rates & BIT(i))
110                         basic = 0x80;
111                 *pos++ = basic | (u8) (rate / 5);
112         }
113
114         /* Build IBSS probe response */
115         mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon));
116         memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
117         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
118                                           IEEE80211_STYPE_PROBE_RESP);
119         memset(mgmt->da, 0xff, ETH_ALEN);
120         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
121         memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
122         mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
123         mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
124         mgmt->u.beacon.capab_info = cpu_to_le16(capability);
125
126         pos = skb_put(skb, 2 + ifibss->ssid_len);
127         *pos++ = WLAN_EID_SSID;
128         *pos++ = ifibss->ssid_len;
129         memcpy(pos, ifibss->ssid, ifibss->ssid_len);
130
131         rates = sband->n_bitrates;
132         if (rates > 8)
133                 rates = 8;
134         pos = skb_put(skb, 2 + rates);
135         *pos++ = WLAN_EID_SUPP_RATES;
136         *pos++ = rates;
137         memcpy(pos, supp_rates, rates);
138
139         if (sband->band == IEEE80211_BAND_2GHZ) {
140                 pos = skb_put(skb, 2 + 1);
141                 *pos++ = WLAN_EID_DS_PARAMS;
142                 *pos++ = 1;
143                 *pos++ = ieee80211_frequency_to_channel(chan->center_freq);
144         }
145
146         pos = skb_put(skb, 2 + 2);
147         *pos++ = WLAN_EID_IBSS_PARAMS;
148         *pos++ = 2;
149         /* FIX: set ATIM window based on scan results */
150         *pos++ = 0;
151         *pos++ = 0;
152
153         if (sband->n_bitrates > 8) {
154                 rates = sband->n_bitrates - 8;
155                 pos = skb_put(skb, 2 + rates);
156                 *pos++ = WLAN_EID_EXT_SUPP_RATES;
157                 *pos++ = rates;
158                 memcpy(pos, &supp_rates[8], rates);
159         }
160
161         if (ifibss->ie_len)
162                 memcpy(skb_put(skb, ifibss->ie_len),
163                        ifibss->ie, ifibss->ie_len);
164
165         rcu_assign_pointer(ifibss->presp, skb);
166
167         sdata->vif.bss_conf.beacon_int = beacon_int;
168         bss_change = BSS_CHANGED_BEACON_INT;
169         bss_change |= ieee80211_reset_erp_info(sdata);
170         bss_change |= BSS_CHANGED_BSSID;
171         bss_change |= BSS_CHANGED_BEACON;
172         bss_change |= BSS_CHANGED_BEACON_ENABLED;
173         ieee80211_bss_info_change_notify(sdata, bss_change);
174
175         ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates);
176
177         ifibss->state = IEEE80211_IBSS_MLME_JOINED;
178         mod_timer(&ifibss->timer,
179                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
180
181         bss = cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel,
182                                         mgmt, skb->len, 0, GFP_KERNEL);
183         cfg80211_put_bss(bss);
184         cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
185 }
186
187 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
188                                     struct ieee80211_bss *bss)
189 {
190         struct cfg80211_bss *cbss =
191                 container_of((void *)bss, struct cfg80211_bss, priv);
192         struct ieee80211_supported_band *sband;
193         u32 basic_rates;
194         int i, j;
195         u16 beacon_int = cbss->beacon_interval;
196
197         if (beacon_int < 10)
198                 beacon_int = 10;
199
200         sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
201
202         basic_rates = 0;
203
204         for (i = 0; i < bss->supp_rates_len; i++) {
205                 int rate = (bss->supp_rates[i] & 0x7f) * 5;
206                 bool is_basic = !!(bss->supp_rates[i] & 0x80);
207
208                 for (j = 0; j < sband->n_bitrates; j++) {
209                         if (sband->bitrates[j].bitrate == rate) {
210                                 if (is_basic)
211                                         basic_rates |= BIT(j);
212                                 break;
213                         }
214                 }
215         }
216
217         __ieee80211_sta_join_ibss(sdata, cbss->bssid,
218                                   beacon_int,
219                                   cbss->channel,
220                                   basic_rates,
221                                   cbss->capability,
222                                   cbss->tsf);
223 }
224
225 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
226                                   struct ieee80211_mgmt *mgmt,
227                                   size_t len,
228                                   struct ieee80211_rx_status *rx_status,
229                                   struct ieee802_11_elems *elems,
230                                   bool beacon)
231 {
232         struct ieee80211_local *local = sdata->local;
233         int freq;
234         struct cfg80211_bss *cbss;
235         struct ieee80211_bss *bss;
236         struct sta_info *sta;
237         struct ieee80211_channel *channel;
238         u64 beacon_timestamp, rx_timestamp;
239         u32 supp_rates = 0;
240         enum ieee80211_band band = rx_status->band;
241
242         if (elems->ds_params && elems->ds_params_len == 1)
243                 freq = ieee80211_channel_to_frequency(elems->ds_params[0]);
244         else
245                 freq = rx_status->freq;
246
247         channel = ieee80211_get_channel(local->hw.wiphy, freq);
248
249         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
250                 return;
251
252         if (sdata->vif.type == NL80211_IFTYPE_ADHOC && elems->supp_rates &&
253             memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) {
254                 supp_rates = ieee80211_sta_get_rates(local, elems, band);
255
256                 rcu_read_lock();
257
258                 sta = sta_info_get(sdata, mgmt->sa);
259                 if (sta) {
260                         u32 prev_rates;
261
262                         prev_rates = sta->sta.supp_rates[band];
263                         /* make sure mandatory rates are always added */
264                         sta->sta.supp_rates[band] = supp_rates |
265                                 ieee80211_mandatory_rates(local, band);
266
267 #ifdef CONFIG_MAC80211_IBSS_DEBUG
268                         if (sta->sta.supp_rates[band] != prev_rates)
269                                 printk(KERN_DEBUG "%s: updated supp_rates set "
270                                     "for %pM based on beacon info (0x%llx | "
271                                     "0x%llx -> 0x%llx)\n",
272                                     sdata->name,
273                                     sta->sta.addr,
274                                     (unsigned long long) prev_rates,
275                                     (unsigned long long) supp_rates,
276                                     (unsigned long long) sta->sta.supp_rates[band]);
277 #endif
278                         rcu_read_unlock();
279                 } else {
280                         rcu_read_unlock();
281                         ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
282                                                supp_rates, GFP_KERNEL);
283                 }
284         }
285
286         bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
287                                         channel, beacon);
288         if (!bss)
289                 return;
290
291         cbss = container_of((void *)bss, struct cfg80211_bss, priv);
292
293         /* was just updated in ieee80211_bss_info_update */
294         beacon_timestamp = cbss->tsf;
295
296         /* check if we need to merge IBSS */
297
298         /* we use a fixed BSSID */
299         if (sdata->u.ibss.fixed_bssid)
300                 goto put_bss;
301
302         /* not an IBSS */
303         if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
304                 goto put_bss;
305
306         /* different channel */
307         if (cbss->channel != local->oper_channel)
308                 goto put_bss;
309
310         /* different SSID */
311         if (elems->ssid_len != sdata->u.ibss.ssid_len ||
312             memcmp(elems->ssid, sdata->u.ibss.ssid,
313                                 sdata->u.ibss.ssid_len))
314                 goto put_bss;
315
316         /* same BSSID */
317         if (memcmp(cbss->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0)
318                 goto put_bss;
319
320         if (rx_status->flag & RX_FLAG_TSFT) {
321                 /*
322                  * For correct IBSS merging we need mactime; since mactime is
323                  * defined as the time the first data symbol of the frame hits
324                  * the PHY, and the timestamp of the beacon is defined as "the
325                  * time that the data symbol containing the first bit of the
326                  * timestamp is transmitted to the PHY plus the transmitting
327                  * STA's delays through its local PHY from the MAC-PHY
328                  * interface to its interface with the WM" (802.11 11.1.2)
329                  * - equals the time this bit arrives at the receiver - we have
330                  * to take into account the offset between the two.
331                  *
332                  * E.g. at 1 MBit that means mactime is 192 usec earlier
333                  * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
334                  */
335                 int rate;
336
337                 if (rx_status->flag & RX_FLAG_HT)
338                         rate = 65; /* TODO: HT rates */
339                 else
340                         rate = local->hw.wiphy->bands[band]->
341                                 bitrates[rx_status->rate_idx].bitrate;
342
343                 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
344         } else {
345                 /*
346                  * second best option: get current TSF
347                  * (will return -1 if not supported)
348                  */
349                 rx_timestamp = drv_get_tsf(local);
350         }
351
352 #ifdef CONFIG_MAC80211_IBSS_DEBUG
353         printk(KERN_DEBUG "RX beacon SA=%pM BSSID="
354                "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
355                mgmt->sa, mgmt->bssid,
356                (unsigned long long)rx_timestamp,
357                (unsigned long long)beacon_timestamp,
358                (unsigned long long)(rx_timestamp - beacon_timestamp),
359                jiffies);
360 #endif
361
362         /* give slow hardware some time to do the TSF sync */
363         if (rx_timestamp < IEEE80211_IBSS_MERGE_DELAY)
364                 goto put_bss;
365
366         if (beacon_timestamp > rx_timestamp) {
367 #ifdef CONFIG_MAC80211_IBSS_DEBUG
368                 printk(KERN_DEBUG "%s: beacon TSF higher than "
369                        "local TSF - IBSS merge with BSSID %pM\n",
370                        sdata->name, mgmt->bssid);
371 #endif
372                 ieee80211_sta_join_ibss(sdata, bss);
373                 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa,
374                                        supp_rates, GFP_KERNEL);
375         }
376
377  put_bss:
378         ieee80211_rx_bss_put(local, bss);
379 }
380
381 /*
382  * Add a new IBSS station, will also be called by the RX code when,
383  * in IBSS mode, receiving a frame from a yet-unknown station, hence
384  * must be callable in atomic context.
385  */
386 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
387                                         u8 *bssid,u8 *addr, u32 supp_rates,
388                                         gfp_t gfp)
389 {
390         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
391         struct ieee80211_local *local = sdata->local;
392         struct sta_info *sta;
393         int band = local->hw.conf.channel->band;
394
395         /*
396          * XXX: Consider removing the least recently used entry and
397          *      allow new one to be added.
398          */
399         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
400                 if (net_ratelimit())
401                         printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
402                                sdata->name, addr);
403                 return NULL;
404         }
405
406         if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
407                 return NULL;
408
409         if (compare_ether_addr(bssid, sdata->u.ibss.bssid))
410                 return NULL;
411
412 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
413         printk(KERN_DEBUG "%s: Adding new IBSS station %pM (dev=%s)\n",
414                wiphy_name(local->hw.wiphy), addr, sdata->name);
415 #endif
416
417         sta = sta_info_alloc(sdata, addr, gfp);
418         if (!sta)
419                 return NULL;
420
421         set_sta_flags(sta, WLAN_STA_AUTHORIZED);
422
423         /* make sure mandatory rates are always added */
424         sta->sta.supp_rates[band] = supp_rates |
425                         ieee80211_mandatory_rates(local, band);
426
427         rate_control_rate_init(sta);
428
429         /* If it fails, maybe we raced another insertion? */
430         if (sta_info_insert(sta))
431                 return sta_info_get(sdata, addr);
432         return sta;
433 }
434
435 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
436 {
437         struct ieee80211_local *local = sdata->local;
438         int active = 0;
439         struct sta_info *sta;
440
441         rcu_read_lock();
442
443         list_for_each_entry_rcu(sta, &local->sta_list, list) {
444                 if (sta->sdata == sdata &&
445                     time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
446                                jiffies)) {
447                         active++;
448                         break;
449                 }
450         }
451
452         rcu_read_unlock();
453
454         return active;
455 }
456
457 /*
458  * This function is called with state == IEEE80211_IBSS_MLME_JOINED
459  */
460
461 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
462 {
463         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
464
465         mod_timer(&ifibss->timer,
466                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
467
468         ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
469
470         if (time_before(jiffies, ifibss->last_scan_completed +
471                        IEEE80211_IBSS_MERGE_INTERVAL))
472                 return;
473
474         if (ieee80211_sta_active_ibss(sdata))
475                 return;
476
477         if (ifibss->fixed_channel)
478                 return;
479
480         printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
481                "IBSS networks with same SSID (merge)\n", sdata->name);
482
483         ieee80211_request_internal_scan(sdata, ifibss->ssid, ifibss->ssid_len);
484 }
485
486 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
487 {
488         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
489         struct ieee80211_local *local = sdata->local;
490         struct ieee80211_supported_band *sband;
491         u8 bssid[ETH_ALEN];
492         u16 capability;
493         int i;
494
495         if (ifibss->fixed_bssid) {
496                 memcpy(bssid, ifibss->bssid, ETH_ALEN);
497         } else {
498                 /* Generate random, not broadcast, locally administered BSSID. Mix in
499                  * own MAC address to make sure that devices that do not have proper
500                  * random number generator get different BSSID. */
501                 get_random_bytes(bssid, ETH_ALEN);
502                 for (i = 0; i < ETH_ALEN; i++)
503                         bssid[i] ^= sdata->vif.addr[i];
504                 bssid[0] &= ~0x01;
505                 bssid[0] |= 0x02;
506         }
507
508         printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n",
509                sdata->name, bssid);
510
511         sband = local->hw.wiphy->bands[ifibss->channel->band];
512
513         capability = WLAN_CAPABILITY_IBSS;
514
515         if (ifibss->privacy)
516                 capability |= WLAN_CAPABILITY_PRIVACY;
517         else
518                 sdata->drop_unencrypted = 0;
519
520         __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
521                                   ifibss->channel, 3, /* first two are basic */
522                                   capability, 0);
523 }
524
525 /*
526  * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
527  */
528
529 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
530 {
531         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
532         struct ieee80211_local *local = sdata->local;
533         struct cfg80211_bss *cbss;
534         struct ieee80211_channel *chan = NULL;
535         const u8 *bssid = NULL;
536         int active_ibss;
537         u16 capability;
538
539         active_ibss = ieee80211_sta_active_ibss(sdata);
540 #ifdef CONFIG_MAC80211_IBSS_DEBUG
541         printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n",
542                sdata->name, active_ibss);
543 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
544
545         if (active_ibss)
546                 return;
547
548         capability = WLAN_CAPABILITY_IBSS;
549         if (ifibss->privacy)
550                 capability |= WLAN_CAPABILITY_PRIVACY;
551         if (ifibss->fixed_bssid)
552                 bssid = ifibss->bssid;
553         if (ifibss->fixed_channel)
554                 chan = ifibss->channel;
555         if (!is_zero_ether_addr(ifibss->bssid))
556                 bssid = ifibss->bssid;
557         cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
558                                 ifibss->ssid, ifibss->ssid_len,
559                                 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
560                                 capability);
561
562         if (cbss) {
563                 struct ieee80211_bss *bss;
564
565                 bss = (void *)cbss->priv;
566 #ifdef CONFIG_MAC80211_IBSS_DEBUG
567                 printk(KERN_DEBUG "   sta_find_ibss: selected %pM current "
568                        "%pM\n", cbss->bssid, ifibss->bssid);
569 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
570
571                 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM"
572                        " based on configured SSID\n",
573                        sdata->name, cbss->bssid);
574
575                 ieee80211_sta_join_ibss(sdata, bss);
576                 ieee80211_rx_bss_put(local, bss);
577                 return;
578         }
579
580 #ifdef CONFIG_MAC80211_IBSS_DEBUG
581         printk(KERN_DEBUG "   did not try to join ibss\n");
582 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
583
584         /* Selected IBSS not found in current scan results - try to scan */
585         if (time_after(jiffies, ifibss->last_scan_completed +
586                                         IEEE80211_SCAN_INTERVAL)) {
587                 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
588                        "join\n", sdata->name);
589
590                 ieee80211_request_internal_scan(sdata, ifibss->ssid,
591                                                 ifibss->ssid_len);
592         } else {
593                 int interval = IEEE80211_SCAN_INTERVAL;
594
595                 if (time_after(jiffies, ifibss->ibss_join_req +
596                                IEEE80211_IBSS_JOIN_TIMEOUT)) {
597                         if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
598                                 ieee80211_sta_create_ibss(sdata);
599                                 return;
600                         }
601                         printk(KERN_DEBUG "%s: IBSS not allowed on"
602                                " %d MHz\n", sdata->name,
603                                local->hw.conf.channel->center_freq);
604
605                         /* No IBSS found - decrease scan interval and continue
606                          * scanning. */
607                         interval = IEEE80211_SCAN_INTERVAL_SLOW;
608                 }
609
610                 mod_timer(&ifibss->timer,
611                           round_jiffies(jiffies + interval));
612         }
613 }
614
615 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
616                                         struct ieee80211_mgmt *mgmt,
617                                         size_t len)
618 {
619         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
620         struct ieee80211_local *local = sdata->local;
621         int tx_last_beacon;
622         struct sk_buff *skb;
623         struct ieee80211_mgmt *resp;
624         u8 *pos, *end;
625
626         if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
627             len < 24 + 2 || !ifibss->presp)
628                 return;
629
630         tx_last_beacon = drv_tx_last_beacon(local);
631
632 #ifdef CONFIG_MAC80211_IBSS_DEBUG
633         printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM"
634                " (tx_last_beacon=%d)\n",
635                sdata->name, mgmt->sa, mgmt->da,
636                mgmt->bssid, tx_last_beacon);
637 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
638
639         if (!tx_last_beacon)
640                 return;
641
642         if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 &&
643             memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0)
644                 return;
645
646         end = ((u8 *) mgmt) + len;
647         pos = mgmt->u.probe_req.variable;
648         if (pos[0] != WLAN_EID_SSID ||
649             pos + 2 + pos[1] > end) {
650 #ifdef CONFIG_MAC80211_IBSS_DEBUG
651                 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq "
652                        "from %pM\n",
653                        sdata->name, mgmt->sa);
654 #endif
655                 return;
656         }
657         if (pos[1] != 0 &&
658             (pos[1] != ifibss->ssid_len ||
659              memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
660                 /* Ignore ProbeReq for foreign SSID */
661                 return;
662         }
663
664         /* Reply with ProbeResp */
665         skb = skb_copy(ifibss->presp, GFP_KERNEL);
666         if (!skb)
667                 return;
668
669         resp = (struct ieee80211_mgmt *) skb->data;
670         memcpy(resp->da, mgmt->sa, ETH_ALEN);
671 #ifdef CONFIG_MAC80211_IBSS_DEBUG
672         printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n",
673                sdata->name, resp->da);
674 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
675         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
676         ieee80211_tx_skb(sdata, skb);
677 }
678
679 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
680                                          struct ieee80211_mgmt *mgmt,
681                                          size_t len,
682                                          struct ieee80211_rx_status *rx_status)
683 {
684         size_t baselen;
685         struct ieee802_11_elems elems;
686
687         if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN))
688                 return; /* ignore ProbeResp to foreign address */
689
690         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
691         if (baselen > len)
692                 return;
693
694         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
695                                 &elems);
696
697         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
698 }
699
700 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
701                                      struct ieee80211_mgmt *mgmt,
702                                      size_t len,
703                                      struct ieee80211_rx_status *rx_status)
704 {
705         size_t baselen;
706         struct ieee802_11_elems elems;
707
708         /* Process beacon from the current BSS */
709         baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
710         if (baselen > len)
711                 return;
712
713         ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
714
715         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
716 }
717
718 static void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
719                                           struct sk_buff *skb)
720 {
721         struct ieee80211_rx_status *rx_status;
722         struct ieee80211_mgmt *mgmt;
723         u16 fc;
724
725         rx_status = IEEE80211_SKB_RXCB(skb);
726         mgmt = (struct ieee80211_mgmt *) skb->data;
727         fc = le16_to_cpu(mgmt->frame_control);
728
729         switch (fc & IEEE80211_FCTL_STYPE) {
730         case IEEE80211_STYPE_PROBE_REQ:
731                 ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len);
732                 break;
733         case IEEE80211_STYPE_PROBE_RESP:
734                 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
735                                              rx_status);
736                 break;
737         case IEEE80211_STYPE_BEACON:
738                 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
739                                          rx_status);
740                 break;
741         case IEEE80211_STYPE_AUTH:
742                 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
743                 break;
744         }
745
746         kfree_skb(skb);
747 }
748
749 static void ieee80211_ibss_work(struct work_struct *work)
750 {
751         struct ieee80211_sub_if_data *sdata =
752                 container_of(work, struct ieee80211_sub_if_data, u.ibss.work);
753         struct ieee80211_local *local = sdata->local;
754         struct ieee80211_if_ibss *ifibss;
755         struct sk_buff *skb;
756
757         if (WARN_ON(local->suspended))
758                 return;
759
760         if (!ieee80211_sdata_running(sdata))
761                 return;
762
763         if (local->scanning)
764                 return;
765
766         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_ADHOC))
767                 return;
768         ifibss = &sdata->u.ibss;
769
770         while ((skb = skb_dequeue(&ifibss->skb_queue)))
771                 ieee80211_ibss_rx_queued_mgmt(sdata, skb);
772
773         if (!test_and_clear_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request))
774                 return;
775
776         switch (ifibss->state) {
777         case IEEE80211_IBSS_MLME_SEARCH:
778                 ieee80211_sta_find_ibss(sdata);
779                 break;
780         case IEEE80211_IBSS_MLME_JOINED:
781                 ieee80211_sta_merge_ibss(sdata);
782                 break;
783         default:
784                 WARN_ON(1);
785                 break;
786         }
787 }
788
789 static void ieee80211_ibss_timer(unsigned long data)
790 {
791         struct ieee80211_sub_if_data *sdata =
792                 (struct ieee80211_sub_if_data *) data;
793         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
794         struct ieee80211_local *local = sdata->local;
795
796         if (local->quiescing) {
797                 ifibss->timer_running = true;
798                 return;
799         }
800
801         set_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request);
802         ieee80211_queue_work(&local->hw, &ifibss->work);
803 }
804
805 #ifdef CONFIG_PM
806 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata)
807 {
808         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
809
810         cancel_work_sync(&ifibss->work);
811         if (del_timer_sync(&ifibss->timer))
812                 ifibss->timer_running = true;
813 }
814
815 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata)
816 {
817         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
818
819         if (ifibss->timer_running) {
820                 add_timer(&ifibss->timer);
821                 ifibss->timer_running = false;
822         }
823 }
824 #endif
825
826 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
827 {
828         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
829
830         INIT_WORK(&ifibss->work, ieee80211_ibss_work);
831         setup_timer(&ifibss->timer, ieee80211_ibss_timer,
832                     (unsigned long) sdata);
833         skb_queue_head_init(&ifibss->skb_queue);
834 }
835
836 /* scan finished notification */
837 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
838 {
839         struct ieee80211_sub_if_data *sdata;
840
841         mutex_lock(&local->iflist_mtx);
842         list_for_each_entry(sdata, &local->interfaces, list) {
843                 if (!ieee80211_sdata_running(sdata))
844                         continue;
845                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
846                         continue;
847                 if (!sdata->u.ibss.ssid_len)
848                         continue;
849                 sdata->u.ibss.last_scan_completed = jiffies;
850                 mod_timer(&sdata->u.ibss.timer, 0);
851         }
852         mutex_unlock(&local->iflist_mtx);
853 }
854
855 ieee80211_rx_result
856 ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
857 {
858         struct ieee80211_local *local = sdata->local;
859         struct ieee80211_mgmt *mgmt;
860         u16 fc;
861
862         if (skb->len < 24)
863                 return RX_DROP_MONITOR;
864
865         mgmt = (struct ieee80211_mgmt *) skb->data;
866         fc = le16_to_cpu(mgmt->frame_control);
867
868         switch (fc & IEEE80211_FCTL_STYPE) {
869         case IEEE80211_STYPE_PROBE_RESP:
870         case IEEE80211_STYPE_BEACON:
871         case IEEE80211_STYPE_PROBE_REQ:
872         case IEEE80211_STYPE_AUTH:
873                 skb_queue_tail(&sdata->u.ibss.skb_queue, skb);
874                 ieee80211_queue_work(&local->hw, &sdata->u.ibss.work);
875                 return RX_QUEUED;
876         }
877
878         return RX_DROP_MONITOR;
879 }
880
881 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
882                         struct cfg80211_ibss_params *params)
883 {
884         struct sk_buff *skb;
885
886         if (params->bssid) {
887                 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
888                 sdata->u.ibss.fixed_bssid = true;
889         } else
890                 sdata->u.ibss.fixed_bssid = false;
891
892         sdata->u.ibss.privacy = params->privacy;
893
894         sdata->vif.bss_conf.beacon_int = params->beacon_interval;
895
896         sdata->u.ibss.channel = params->channel;
897         sdata->u.ibss.fixed_channel = params->channel_fixed;
898
899         if (params->ie) {
900                 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
901                                            GFP_KERNEL);
902                 if (sdata->u.ibss.ie)
903                         sdata->u.ibss.ie_len = params->ie_len;
904         }
905
906         skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
907                             36 /* bitrates */ +
908                             34 /* SSID */ +
909                             3  /* DS params */ +
910                             4  /* IBSS params */ +
911                             params->ie_len);
912         if (!skb)
913                 return -ENOMEM;
914
915         sdata->u.ibss.skb = skb;
916         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
917         sdata->u.ibss.ibss_join_req = jiffies;
918
919         memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);
920
921         /*
922          * The ssid_len setting below is used to see whether
923          * we are active, and we need all other settings
924          * before that may get visible.
925          */
926         mb();
927
928         sdata->u.ibss.ssid_len = params->ssid_len;
929
930         ieee80211_recalc_idle(sdata->local);
931
932         set_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
933         ieee80211_queue_work(&sdata->local->hw, &sdata->u.ibss.work);
934
935         return 0;
936 }
937
938 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
939 {
940         struct sk_buff *skb;
941
942         del_timer_sync(&sdata->u.ibss.timer);
943         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
944         cancel_work_sync(&sdata->u.ibss.work);
945         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
946
947         sta_info_flush(sdata->local, sdata);
948
949         /* remove beacon */
950         kfree(sdata->u.ibss.ie);
951         skb = sdata->u.ibss.presp;
952         rcu_assign_pointer(sdata->u.ibss.presp, NULL);
953         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
954         synchronize_rcu();
955         kfree_skb(skb);
956
957         skb_queue_purge(&sdata->u.ibss.skb_queue);
958         memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
959         sdata->u.ibss.ssid_len = 0;
960
961         ieee80211_recalc_idle(sdata->local);
962
963         return 0;
964 }