8e2220000e5c44254ae5c4c9ddbb03bec11b5db5
[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         u32 bss_change;
77         u8 supp_rates[IEEE80211_MAX_SUPP_RATES];
78
79         /* Reset own TSF to allow time synchronization work. */
80         drv_reset_tsf(local);
81
82         skb = ifibss->skb;
83         rcu_assign_pointer(ifibss->presp, NULL);
84         synchronize_rcu();
85         skb->data = skb->head;
86         skb->len = 0;
87         skb_reset_tail_pointer(skb);
88         skb_reserve(skb, sdata->local->hw.extra_tx_headroom);
89
90         if (memcmp(ifibss->bssid, bssid, ETH_ALEN))
91                 sta_info_flush(sdata->local, sdata);
92
93         memcpy(ifibss->bssid, bssid, ETH_ALEN);
94
95         sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
96
97         local->oper_channel = chan;
98         local->oper_channel_type = NL80211_CHAN_NO_HT;
99         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
100
101         sband = local->hw.wiphy->bands[chan->band];
102
103         /* build supported rates array */
104         pos = supp_rates;
105         for (i = 0; i < sband->n_bitrates; i++) {
106                 int rate = sband->bitrates[i].bitrate;
107                 u8 basic = 0;
108                 if (basic_rates & BIT(i))
109                         basic = 0x80;
110                 *pos++ = basic | (u8) (rate / 5);
111         }
112
113         /* Build IBSS probe response */
114         mgmt = (void *) skb_put(skb, 24 + sizeof(mgmt->u.beacon));
115         memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
116         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
117                                           IEEE80211_STYPE_PROBE_RESP);
118         memset(mgmt->da, 0xff, ETH_ALEN);
119         memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
120         memcpy(mgmt->bssid, ifibss->bssid, ETH_ALEN);
121         mgmt->u.beacon.beacon_int = cpu_to_le16(beacon_int);
122         mgmt->u.beacon.timestamp = cpu_to_le64(tsf);
123         mgmt->u.beacon.capab_info = cpu_to_le16(capability);
124
125         pos = skb_put(skb, 2 + ifibss->ssid_len);
126         *pos++ = WLAN_EID_SSID;
127         *pos++ = ifibss->ssid_len;
128         memcpy(pos, ifibss->ssid, ifibss->ssid_len);
129
130         rates = sband->n_bitrates;
131         if (rates > 8)
132                 rates = 8;
133         pos = skb_put(skb, 2 + rates);
134         *pos++ = WLAN_EID_SUPP_RATES;
135         *pos++ = rates;
136         memcpy(pos, supp_rates, rates);
137
138         if (sband->band == IEEE80211_BAND_2GHZ) {
139                 pos = skb_put(skb, 2 + 1);
140                 *pos++ = WLAN_EID_DS_PARAMS;
141                 *pos++ = 1;
142                 *pos++ = ieee80211_frequency_to_channel(chan->center_freq);
143         }
144
145         pos = skb_put(skb, 2 + 2);
146         *pos++ = WLAN_EID_IBSS_PARAMS;
147         *pos++ = 2;
148         /* FIX: set ATIM window based on scan results */
149         *pos++ = 0;
150         *pos++ = 0;
151
152         if (sband->n_bitrates > 8) {
153                 rates = sband->n_bitrates - 8;
154                 pos = skb_put(skb, 2 + rates);
155                 *pos++ = WLAN_EID_EXT_SUPP_RATES;
156                 *pos++ = rates;
157                 memcpy(pos, &supp_rates[8], rates);
158         }
159
160         if (ifibss->ie_len)
161                 memcpy(skb_put(skb, ifibss->ie_len),
162                        ifibss->ie, ifibss->ie_len);
163
164         rcu_assign_pointer(ifibss->presp, skb);
165
166         sdata->vif.bss_conf.beacon_int = beacon_int;
167         bss_change = BSS_CHANGED_BEACON_INT;
168         bss_change |= ieee80211_reset_erp_info(sdata);
169         bss_change |= BSS_CHANGED_BSSID;
170         bss_change |= BSS_CHANGED_BEACON;
171         bss_change |= BSS_CHANGED_BEACON_ENABLED;
172         ieee80211_bss_info_change_notify(sdata, bss_change);
173
174         ieee80211_sta_def_wmm_params(sdata, sband->n_bitrates, supp_rates);
175
176         ifibss->state = IEEE80211_IBSS_MLME_JOINED;
177         mod_timer(&ifibss->timer,
178                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
179
180         cfg80211_inform_bss_frame(local->hw.wiphy, local->hw.conf.channel,
181                                   mgmt, skb->len, 0, GFP_KERNEL);
182         cfg80211_ibss_joined(sdata->dev, ifibss->bssid, GFP_KERNEL);
183 }
184
185 static void ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
186                                     struct ieee80211_bss *bss)
187 {
188         struct ieee80211_supported_band *sband;
189         u32 basic_rates;
190         int i, j;
191         u16 beacon_int = bss->cbss.beacon_interval;
192
193         if (beacon_int < 10)
194                 beacon_int = 10;
195
196         sband = sdata->local->hw.wiphy->bands[bss->cbss.channel->band];
197
198         basic_rates = 0;
199
200         for (i = 0; i < bss->supp_rates_len; i++) {
201                 int rate = (bss->supp_rates[i] & 0x7f) * 5;
202                 bool is_basic = !!(bss->supp_rates[i] & 0x80);
203
204                 for (j = 0; j < sband->n_bitrates; j++) {
205                         if (sband->bitrates[j].bitrate == rate) {
206                                 if (is_basic)
207                                         basic_rates |= BIT(j);
208                                 break;
209                         }
210                 }
211         }
212
213         __ieee80211_sta_join_ibss(sdata, bss->cbss.bssid,
214                                   beacon_int,
215                                   bss->cbss.channel,
216                                   basic_rates,
217                                   bss->cbss.capability,
218                                   bss->cbss.tsf);
219 }
220
221 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
222                                   struct ieee80211_mgmt *mgmt,
223                                   size_t len,
224                                   struct ieee80211_rx_status *rx_status,
225                                   struct ieee802_11_elems *elems,
226                                   bool beacon)
227 {
228         struct ieee80211_local *local = sdata->local;
229         int freq;
230         struct ieee80211_bss *bss;
231         struct sta_info *sta;
232         struct ieee80211_channel *channel;
233         u64 beacon_timestamp, rx_timestamp;
234         u32 supp_rates = 0;
235         enum ieee80211_band band = rx_status->band;
236
237         if (elems->ds_params && elems->ds_params_len == 1)
238                 freq = ieee80211_channel_to_frequency(elems->ds_params[0]);
239         else
240                 freq = rx_status->freq;
241
242         channel = ieee80211_get_channel(local->hw.wiphy, freq);
243
244         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
245                 return;
246
247         if (sdata->vif.type == NL80211_IFTYPE_ADHOC && elems->supp_rates &&
248             memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) {
249                 supp_rates = ieee80211_sta_get_rates(local, elems, band);
250
251                 rcu_read_lock();
252
253                 sta = sta_info_get(local, mgmt->sa);
254                 if (sta) {
255                         u32 prev_rates;
256
257                         prev_rates = sta->sta.supp_rates[band];
258                         /* make sure mandatory rates are always added */
259                         sta->sta.supp_rates[band] = supp_rates |
260                                 ieee80211_mandatory_rates(local, band);
261
262 #ifdef CONFIG_MAC80211_IBSS_DEBUG
263                         if (sta->sta.supp_rates[band] != prev_rates)
264                                 printk(KERN_DEBUG "%s: updated supp_rates set "
265                                     "for %pM based on beacon info (0x%llx | "
266                                     "0x%llx -> 0x%llx)\n",
267                                     sdata->dev->name,
268                                     sta->sta.addr,
269                                     (unsigned long long) prev_rates,
270                                     (unsigned long long) supp_rates,
271                                     (unsigned long long) sta->sta.supp_rates[band]);
272 #endif
273                 } else
274                         ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates);
275
276                 rcu_read_unlock();
277         }
278
279         bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
280                                         channel, beacon);
281         if (!bss)
282                 return;
283
284         /* was just updated in ieee80211_bss_info_update */
285         beacon_timestamp = bss->cbss.tsf;
286
287         /* check if we need to merge IBSS */
288
289         /* merge only on beacons (???) */
290         if (!beacon)
291                 goto put_bss;
292
293         /* we use a fixed BSSID */
294         if (sdata->u.ibss.bssid)
295                 goto put_bss;
296
297         /* not an IBSS */
298         if (!(bss->cbss.capability & WLAN_CAPABILITY_IBSS))
299                 goto put_bss;
300
301         /* different channel */
302         if (bss->cbss.channel != local->oper_channel)
303                 goto put_bss;
304
305         /* different SSID */
306         if (elems->ssid_len != sdata->u.ibss.ssid_len ||
307             memcmp(elems->ssid, sdata->u.ibss.ssid,
308                                 sdata->u.ibss.ssid_len))
309                 goto put_bss;
310
311         /* same BSSID */
312         if (memcmp(bss->cbss.bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0)
313                 goto put_bss;
314
315         if (rx_status->flag & RX_FLAG_TSFT) {
316                 /*
317                  * For correct IBSS merging we need mactime; since mactime is
318                  * defined as the time the first data symbol of the frame hits
319                  * the PHY, and the timestamp of the beacon is defined as "the
320                  * time that the data symbol containing the first bit of the
321                  * timestamp is transmitted to the PHY plus the transmitting
322                  * STA's delays through its local PHY from the MAC-PHY
323                  * interface to its interface with the WM" (802.11 11.1.2)
324                  * - equals the time this bit arrives at the receiver - we have
325                  * to take into account the offset between the two.
326                  *
327                  * E.g. at 1 MBit that means mactime is 192 usec earlier
328                  * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
329                  */
330                 int rate;
331
332                 if (rx_status->flag & RX_FLAG_HT)
333                         rate = 65; /* TODO: HT rates */
334                 else
335                         rate = local->hw.wiphy->bands[band]->
336                                 bitrates[rx_status->rate_idx].bitrate;
337
338                 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
339         } else {
340                 /*
341                  * second best option: get current TSF
342                  * (will return -1 if not supported)
343                  */
344                 rx_timestamp = drv_get_tsf(local);
345         }
346
347 #ifdef CONFIG_MAC80211_IBSS_DEBUG
348         printk(KERN_DEBUG "RX beacon SA=%pM BSSID="
349                "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
350                mgmt->sa, mgmt->bssid,
351                (unsigned long long)rx_timestamp,
352                (unsigned long long)beacon_timestamp,
353                (unsigned long long)(rx_timestamp - beacon_timestamp),
354                jiffies);
355 #endif
356
357         /* give slow hardware some time to do the TSF sync */
358         if (rx_timestamp < IEEE80211_IBSS_MERGE_DELAY)
359                 goto put_bss;
360
361         if (beacon_timestamp > rx_timestamp) {
362 #ifdef CONFIG_MAC80211_IBSS_DEBUG
363                 printk(KERN_DEBUG "%s: beacon TSF higher than "
364                        "local TSF - IBSS merge with BSSID %pM\n",
365                        sdata->dev->name, mgmt->bssid);
366 #endif
367                 ieee80211_sta_join_ibss(sdata, bss);
368                 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates);
369         }
370
371  put_bss:
372         ieee80211_rx_bss_put(local, bss);
373 }
374
375 /*
376  * Add a new IBSS station, will also be called by the RX code when,
377  * in IBSS mode, receiving a frame from a yet-unknown station, hence
378  * must be callable in atomic context.
379  */
380 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
381                                         u8 *bssid,u8 *addr, u32 supp_rates)
382 {
383         struct ieee80211_local *local = sdata->local;
384         struct sta_info *sta;
385         int band = local->hw.conf.channel->band;
386
387         /*
388          * XXX: Consider removing the least recently used entry and
389          *      allow new one to be added.
390          */
391         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
392                 if (net_ratelimit())
393                         printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
394                                sdata->dev->name, addr);
395                 return NULL;
396         }
397
398         if (compare_ether_addr(bssid, sdata->u.ibss.bssid))
399                 return NULL;
400
401 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
402         printk(KERN_DEBUG "%s: Adding new IBSS station %pM (dev=%s)\n",
403                wiphy_name(local->hw.wiphy), addr, sdata->dev->name);
404 #endif
405
406         sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
407         if (!sta)
408                 return NULL;
409
410         set_sta_flags(sta, WLAN_STA_AUTHORIZED);
411
412         /* make sure mandatory rates are always added */
413         sta->sta.supp_rates[band] = supp_rates |
414                         ieee80211_mandatory_rates(local, band);
415
416         rate_control_rate_init(sta);
417
418         if (sta_info_insert(sta))
419                 return NULL;
420
421         return sta;
422 }
423
424 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
425 {
426         struct ieee80211_local *local = sdata->local;
427         int active = 0;
428         struct sta_info *sta;
429
430         rcu_read_lock();
431
432         list_for_each_entry_rcu(sta, &local->sta_list, list) {
433                 if (sta->sdata == sdata &&
434                     time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
435                                jiffies)) {
436                         active++;
437                         break;
438                 }
439         }
440
441         rcu_read_unlock();
442
443         return active;
444 }
445
446
447 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
448 {
449         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
450
451         mod_timer(&ifibss->timer,
452                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
453
454         ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
455
456         if (ieee80211_sta_active_ibss(sdata))
457                 return;
458
459         if (ifibss->fixed_channel)
460                 return;
461
462         printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
463                "IBSS networks with same SSID (merge)\n", sdata->dev->name);
464
465         ieee80211_request_internal_scan(sdata, ifibss->ssid, ifibss->ssid_len);
466 }
467
468 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
469 {
470         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
471         struct ieee80211_local *local = sdata->local;
472         struct ieee80211_supported_band *sband;
473         u8 bssid[ETH_ALEN];
474         u16 capability;
475         int i;
476
477         if (ifibss->fixed_bssid) {
478                 memcpy(bssid, ifibss->bssid, ETH_ALEN);
479         } else {
480                 /* Generate random, not broadcast, locally administered BSSID. Mix in
481                  * own MAC address to make sure that devices that do not have proper
482                  * random number generator get different BSSID. */
483                 get_random_bytes(bssid, ETH_ALEN);
484                 for (i = 0; i < ETH_ALEN; i++)
485                         bssid[i] ^= sdata->dev->dev_addr[i];
486                 bssid[0] &= ~0x01;
487                 bssid[0] |= 0x02;
488         }
489
490         printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n",
491                sdata->dev->name, bssid);
492
493         sband = local->hw.wiphy->bands[ifibss->channel->band];
494
495         capability = WLAN_CAPABILITY_IBSS;
496
497         if (ifibss->privacy)
498                 capability |= WLAN_CAPABILITY_PRIVACY;
499         else
500                 sdata->drop_unencrypted = 0;
501
502         __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
503                                   ifibss->channel, 3, /* first two are basic */
504                                   capability, 0);
505 }
506
507 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
508 {
509         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
510         struct ieee80211_local *local = sdata->local;
511         struct ieee80211_bss *bss;
512         struct ieee80211_channel *chan = NULL;
513         const u8 *bssid = NULL;
514         int active_ibss;
515         u16 capability;
516
517         active_ibss = ieee80211_sta_active_ibss(sdata);
518 #ifdef CONFIG_MAC80211_IBSS_DEBUG
519         printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n",
520                sdata->dev->name, active_ibss);
521 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
522
523         if (active_ibss)
524                 return;
525
526         capability = WLAN_CAPABILITY_IBSS;
527         if (ifibss->privacy)
528                 capability |= WLAN_CAPABILITY_PRIVACY;
529         if (ifibss->fixed_bssid)
530                 bssid = ifibss->bssid;
531         if (ifibss->fixed_channel)
532                 chan = ifibss->channel;
533         if (!is_zero_ether_addr(ifibss->bssid))
534                 bssid = ifibss->bssid;
535         bss = (void *)cfg80211_get_bss(local->hw.wiphy, chan, bssid,
536                                        ifibss->ssid, ifibss->ssid_len,
537                                        WLAN_CAPABILITY_IBSS |
538                                        WLAN_CAPABILITY_PRIVACY,
539                                        capability);
540
541 #ifdef CONFIG_MAC80211_IBSS_DEBUG
542         if (bss)
543                 printk(KERN_DEBUG "   sta_find_ibss: selected %pM current "
544                        "%pM\n", bss->cbss.bssid, ifibss->bssid);
545 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
546
547         if (bss && memcmp(ifibss->bssid, bss->cbss.bssid, ETH_ALEN)) {
548                 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM"
549                        " based on configured SSID\n",
550                        sdata->dev->name, bss->cbss.bssid);
551
552                 ieee80211_sta_join_ibss(sdata, bss);
553                 ieee80211_rx_bss_put(local, bss);
554                 return;
555         } else if (bss)
556                 ieee80211_rx_bss_put(local, bss);
557
558 #ifdef CONFIG_MAC80211_IBSS_DEBUG
559         printk(KERN_DEBUG "   did not try to join ibss\n");
560 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
561
562         /* Selected IBSS not found in current scan results - try to scan */
563         if (ifibss->state == IEEE80211_IBSS_MLME_JOINED &&
564             !ieee80211_sta_active_ibss(sdata)) {
565                 mod_timer(&ifibss->timer,
566                           round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
567         } else if (time_after(jiffies, ifibss->last_scan_completed +
568                                         IEEE80211_SCAN_INTERVAL)) {
569                 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
570                        "join\n", sdata->dev->name);
571
572                 ieee80211_request_internal_scan(sdata, ifibss->ssid,
573                                                 ifibss->ssid_len);
574         } else if (ifibss->state != IEEE80211_IBSS_MLME_JOINED) {
575                 int interval = IEEE80211_SCAN_INTERVAL;
576
577                 if (time_after(jiffies, ifibss->ibss_join_req +
578                                IEEE80211_IBSS_JOIN_TIMEOUT)) {
579                         if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
580                                 ieee80211_sta_create_ibss(sdata);
581                                 return;
582                         }
583                         printk(KERN_DEBUG "%s: IBSS not allowed on"
584                                " %d MHz\n", sdata->dev->name,
585                                local->hw.conf.channel->center_freq);
586
587                         /* No IBSS found - decrease scan interval and continue
588                          * scanning. */
589                         interval = IEEE80211_SCAN_INTERVAL_SLOW;
590                 }
591
592                 ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
593                 mod_timer(&ifibss->timer,
594                           round_jiffies(jiffies + interval));
595         }
596 }
597
598 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
599                                         struct ieee80211_mgmt *mgmt,
600                                         size_t len)
601 {
602         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
603         struct ieee80211_local *local = sdata->local;
604         int tx_last_beacon;
605         struct sk_buff *skb;
606         struct ieee80211_mgmt *resp;
607         u8 *pos, *end;
608
609         if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
610             len < 24 + 2 || !ifibss->presp)
611                 return;
612
613         tx_last_beacon = drv_tx_last_beacon(local);
614
615 #ifdef CONFIG_MAC80211_IBSS_DEBUG
616         printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM"
617                " (tx_last_beacon=%d)\n",
618                sdata->dev->name, mgmt->sa, mgmt->da,
619                mgmt->bssid, tx_last_beacon);
620 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
621
622         if (!tx_last_beacon)
623                 return;
624
625         if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 &&
626             memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0)
627                 return;
628
629         end = ((u8 *) mgmt) + len;
630         pos = mgmt->u.probe_req.variable;
631         if (pos[0] != WLAN_EID_SSID ||
632             pos + 2 + pos[1] > end) {
633 #ifdef CONFIG_MAC80211_IBSS_DEBUG
634                 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq "
635                        "from %pM\n",
636                        sdata->dev->name, mgmt->sa);
637 #endif
638                 return;
639         }
640         if (pos[1] != 0 &&
641             (pos[1] != ifibss->ssid_len ||
642              !memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
643                 /* Ignore ProbeReq for foreign SSID */
644                 return;
645         }
646
647         /* Reply with ProbeResp */
648         skb = skb_copy(ifibss->presp, GFP_KERNEL);
649         if (!skb)
650                 return;
651
652         resp = (struct ieee80211_mgmt *) skb->data;
653         memcpy(resp->da, mgmt->sa, ETH_ALEN);
654 #ifdef CONFIG_MAC80211_IBSS_DEBUG
655         printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n",
656                sdata->dev->name, resp->da);
657 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
658         ieee80211_tx_skb(sdata, skb, 0);
659 }
660
661 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
662                                          struct ieee80211_mgmt *mgmt,
663                                          size_t len,
664                                          struct ieee80211_rx_status *rx_status)
665 {
666         size_t baselen;
667         struct ieee802_11_elems elems;
668
669         if (memcmp(mgmt->da, sdata->dev->dev_addr, ETH_ALEN))
670                 return; /* ignore ProbeResp to foreign address */
671
672         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
673         if (baselen > len)
674                 return;
675
676         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
677                                 &elems);
678
679         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
680 }
681
682 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
683                                      struct ieee80211_mgmt *mgmt,
684                                      size_t len,
685                                      struct ieee80211_rx_status *rx_status)
686 {
687         size_t baselen;
688         struct ieee802_11_elems elems;
689
690         /* Process beacon from the current BSS */
691         baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
692         if (baselen > len)
693                 return;
694
695         ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
696
697         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
698 }
699
700 static void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
701                                           struct sk_buff *skb)
702 {
703         struct ieee80211_rx_status *rx_status;
704         struct ieee80211_mgmt *mgmt;
705         u16 fc;
706
707         rx_status = IEEE80211_SKB_RXCB(skb);
708         mgmt = (struct ieee80211_mgmt *) skb->data;
709         fc = le16_to_cpu(mgmt->frame_control);
710
711         switch (fc & IEEE80211_FCTL_STYPE) {
712         case IEEE80211_STYPE_PROBE_REQ:
713                 ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len);
714                 break;
715         case IEEE80211_STYPE_PROBE_RESP:
716                 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
717                                              rx_status);
718                 break;
719         case IEEE80211_STYPE_BEACON:
720                 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
721                                          rx_status);
722                 break;
723         case IEEE80211_STYPE_AUTH:
724                 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
725                 break;
726         }
727
728         kfree_skb(skb);
729 }
730
731 static void ieee80211_ibss_work(struct work_struct *work)
732 {
733         struct ieee80211_sub_if_data *sdata =
734                 container_of(work, struct ieee80211_sub_if_data, u.ibss.work);
735         struct ieee80211_local *local = sdata->local;
736         struct ieee80211_if_ibss *ifibss;
737         struct sk_buff *skb;
738
739         if (WARN_ON(local->suspended))
740                 return;
741
742         if (!netif_running(sdata->dev))
743                 return;
744
745         if (local->sw_scanning || local->hw_scanning)
746                 return;
747
748         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_ADHOC))
749                 return;
750         ifibss = &sdata->u.ibss;
751
752         while ((skb = skb_dequeue(&ifibss->skb_queue)))
753                 ieee80211_ibss_rx_queued_mgmt(sdata, skb);
754
755         if (!test_and_clear_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request))
756                 return;
757
758         switch (ifibss->state) {
759         case IEEE80211_IBSS_MLME_SEARCH:
760                 ieee80211_sta_find_ibss(sdata);
761                 break;
762         case IEEE80211_IBSS_MLME_JOINED:
763                 ieee80211_sta_merge_ibss(sdata);
764                 break;
765         default:
766                 WARN_ON(1);
767                 break;
768         }
769 }
770
771 static void ieee80211_ibss_timer(unsigned long data)
772 {
773         struct ieee80211_sub_if_data *sdata =
774                 (struct ieee80211_sub_if_data *) data;
775         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
776         struct ieee80211_local *local = sdata->local;
777
778         if (local->quiescing) {
779                 ifibss->timer_running = true;
780                 return;
781         }
782
783         set_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request);
784         queue_work(local->hw.workqueue, &ifibss->work);
785 }
786
787 #ifdef CONFIG_PM
788 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata)
789 {
790         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
791
792         cancel_work_sync(&ifibss->work);
793         if (del_timer_sync(&ifibss->timer))
794                 ifibss->timer_running = true;
795 }
796
797 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata)
798 {
799         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
800
801         if (ifibss->timer_running) {
802                 add_timer(&ifibss->timer);
803                 ifibss->timer_running = false;
804         }
805 }
806 #endif
807
808 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
809 {
810         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
811
812         INIT_WORK(&ifibss->work, ieee80211_ibss_work);
813         setup_timer(&ifibss->timer, ieee80211_ibss_timer,
814                     (unsigned long) sdata);
815         skb_queue_head_init(&ifibss->skb_queue);
816 }
817
818 /* scan finished notification */
819 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
820 {
821         struct ieee80211_sub_if_data *sdata;
822
823         mutex_lock(&local->iflist_mtx);
824         list_for_each_entry(sdata, &local->interfaces, list) {
825                 if (!netif_running(sdata->dev))
826                         continue;
827                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
828                         continue;
829                 if (!sdata->u.ibss.ssid_len)
830                         continue;
831                 sdata->u.ibss.last_scan_completed = jiffies;
832                 ieee80211_sta_find_ibss(sdata);
833         }
834         mutex_unlock(&local->iflist_mtx);
835 }
836
837 ieee80211_rx_result
838 ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
839 {
840         struct ieee80211_local *local = sdata->local;
841         struct ieee80211_mgmt *mgmt;
842         u16 fc;
843
844         if (skb->len < 24)
845                 return RX_DROP_MONITOR;
846
847         mgmt = (struct ieee80211_mgmt *) skb->data;
848         fc = le16_to_cpu(mgmt->frame_control);
849
850         switch (fc & IEEE80211_FCTL_STYPE) {
851         case IEEE80211_STYPE_PROBE_RESP:
852         case IEEE80211_STYPE_BEACON:
853         case IEEE80211_STYPE_PROBE_REQ:
854         case IEEE80211_STYPE_AUTH:
855                 skb_queue_tail(&sdata->u.ibss.skb_queue, skb);
856                 queue_work(local->hw.workqueue, &sdata->u.ibss.work);
857                 return RX_QUEUED;
858         }
859
860         return RX_DROP_MONITOR;
861 }
862
863 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
864                         struct cfg80211_ibss_params *params)
865 {
866         struct sk_buff *skb;
867
868         if (params->bssid) {
869                 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
870                 sdata->u.ibss.fixed_bssid = true;
871         } else
872                 sdata->u.ibss.fixed_bssid = false;
873
874         sdata->u.ibss.privacy = params->privacy;
875
876         sdata->vif.bss_conf.beacon_int = params->beacon_interval;
877
878         sdata->u.ibss.channel = params->channel;
879         sdata->u.ibss.fixed_channel = params->channel_fixed;
880
881         if (params->ie) {
882                 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
883                                            GFP_KERNEL);
884                 if (sdata->u.ibss.ie)
885                         sdata->u.ibss.ie_len = params->ie_len;
886         }
887
888         skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
889                             36 /* bitrates */ +
890                             34 /* SSID */ +
891                             3  /* DS params */ +
892                             4  /* IBSS params */ +
893                             params->ie_len);
894         if (!skb)
895                 return -ENOMEM;
896
897         sdata->u.ibss.skb = skb;
898         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
899         sdata->u.ibss.ibss_join_req = jiffies;
900
901         memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);
902
903         /*
904          * The ssid_len setting below is used to see whether
905          * we are active, and we need all other settings
906          * before that may get visible.
907          */
908         mb();
909
910         sdata->u.ibss.ssid_len = params->ssid_len;
911
912         ieee80211_recalc_idle(sdata->local);
913
914         set_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
915         queue_work(sdata->local->hw.workqueue, &sdata->u.ibss.work);
916
917         return 0;
918 }
919
920 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
921 {
922         struct sk_buff *skb;
923
924         del_timer_sync(&sdata->u.ibss.timer);
925         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
926         cancel_work_sync(&sdata->u.ibss.work);
927         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
928
929         sta_info_flush(sdata->local, sdata);
930
931         /* remove beacon */
932         kfree(sdata->u.ibss.ie);
933         skb = sdata->u.ibss.presp;
934         rcu_assign_pointer(sdata->u.ibss.presp, NULL);
935         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
936         synchronize_rcu();
937         kfree_skb(skb);
938
939         skb_queue_purge(&sdata->u.ibss.skb_queue);
940         memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
941         sdata->u.ibss.ssid_len = 0;
942
943         ieee80211_recalc_idle(sdata->local);
944
945         return 0;
946 }