85c4ba14c77de39bc778e483daafc50468eb96c4
[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                 } else
279                         ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates);
280
281                 rcu_read_unlock();
282         }
283
284         bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
285                                         channel, beacon);
286         if (!bss)
287                 return;
288
289         cbss = container_of((void *)bss, struct cfg80211_bss, priv);
290
291         /* was just updated in ieee80211_bss_info_update */
292         beacon_timestamp = cbss->tsf;
293
294         /* check if we need to merge IBSS */
295
296         /* we use a fixed BSSID */
297         if (sdata->u.ibss.fixed_bssid)
298                 goto put_bss;
299
300         /* not an IBSS */
301         if (!(cbss->capability & WLAN_CAPABILITY_IBSS))
302                 goto put_bss;
303
304         /* different channel */
305         if (cbss->channel != local->oper_channel)
306                 goto put_bss;
307
308         /* different SSID */
309         if (elems->ssid_len != sdata->u.ibss.ssid_len ||
310             memcmp(elems->ssid, sdata->u.ibss.ssid,
311                                 sdata->u.ibss.ssid_len))
312                 goto put_bss;
313
314         /* same BSSID */
315         if (memcmp(cbss->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0)
316                 goto put_bss;
317
318         if (rx_status->flag & RX_FLAG_TSFT) {
319                 /*
320                  * For correct IBSS merging we need mactime; since mactime is
321                  * defined as the time the first data symbol of the frame hits
322                  * the PHY, and the timestamp of the beacon is defined as "the
323                  * time that the data symbol containing the first bit of the
324                  * timestamp is transmitted to the PHY plus the transmitting
325                  * STA's delays through its local PHY from the MAC-PHY
326                  * interface to its interface with the WM" (802.11 11.1.2)
327                  * - equals the time this bit arrives at the receiver - we have
328                  * to take into account the offset between the two.
329                  *
330                  * E.g. at 1 MBit that means mactime is 192 usec earlier
331                  * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
332                  */
333                 int rate;
334
335                 if (rx_status->flag & RX_FLAG_HT)
336                         rate = 65; /* TODO: HT rates */
337                 else
338                         rate = local->hw.wiphy->bands[band]->
339                                 bitrates[rx_status->rate_idx].bitrate;
340
341                 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
342         } else {
343                 /*
344                  * second best option: get current TSF
345                  * (will return -1 if not supported)
346                  */
347                 rx_timestamp = drv_get_tsf(local);
348         }
349
350 #ifdef CONFIG_MAC80211_IBSS_DEBUG
351         printk(KERN_DEBUG "RX beacon SA=%pM BSSID="
352                "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
353                mgmt->sa, mgmt->bssid,
354                (unsigned long long)rx_timestamp,
355                (unsigned long long)beacon_timestamp,
356                (unsigned long long)(rx_timestamp - beacon_timestamp),
357                jiffies);
358 #endif
359
360         /* give slow hardware some time to do the TSF sync */
361         if (rx_timestamp < IEEE80211_IBSS_MERGE_DELAY)
362                 goto put_bss;
363
364         if (beacon_timestamp > rx_timestamp) {
365 #ifdef CONFIG_MAC80211_IBSS_DEBUG
366                 printk(KERN_DEBUG "%s: beacon TSF higher than "
367                        "local TSF - IBSS merge with BSSID %pM\n",
368                        sdata->name, mgmt->bssid);
369 #endif
370                 ieee80211_sta_join_ibss(sdata, bss);
371                 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates);
372         }
373
374  put_bss:
375         ieee80211_rx_bss_put(local, bss);
376 }
377
378 /*
379  * Add a new IBSS station, will also be called by the RX code when,
380  * in IBSS mode, receiving a frame from a yet-unknown station, hence
381  * must be callable in atomic context.
382  */
383 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
384                                         u8 *bssid,u8 *addr, u32 supp_rates)
385 {
386         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
387         struct ieee80211_local *local = sdata->local;
388         struct sta_info *sta;
389         int band = local->hw.conf.channel->band;
390
391         /*
392          * XXX: Consider removing the least recently used entry and
393          *      allow new one to be added.
394          */
395         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
396                 if (net_ratelimit())
397                         printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
398                                sdata->name, addr);
399                 return NULL;
400         }
401
402         if (ifibss->state == IEEE80211_IBSS_MLME_SEARCH)
403                 return NULL;
404
405         if (compare_ether_addr(bssid, sdata->u.ibss.bssid))
406                 return NULL;
407
408 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
409         printk(KERN_DEBUG "%s: Adding new IBSS station %pM (dev=%s)\n",
410                wiphy_name(local->hw.wiphy), addr, sdata->name);
411 #endif
412
413         sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
414         if (!sta)
415                 return NULL;
416
417         set_sta_flags(sta, WLAN_STA_AUTHORIZED);
418
419         /* make sure mandatory rates are always added */
420         sta->sta.supp_rates[band] = supp_rates |
421                         ieee80211_mandatory_rates(local, band);
422
423         rate_control_rate_init(sta);
424
425         if (sta_info_insert(sta))
426                 return NULL;
427
428         return sta;
429 }
430
431 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
432 {
433         struct ieee80211_local *local = sdata->local;
434         int active = 0;
435         struct sta_info *sta;
436
437         rcu_read_lock();
438
439         list_for_each_entry_rcu(sta, &local->sta_list, list) {
440                 if (sta->sdata == sdata &&
441                     time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
442                                jiffies)) {
443                         active++;
444                         break;
445                 }
446         }
447
448         rcu_read_unlock();
449
450         return active;
451 }
452
453 /*
454  * This function is called with state == IEEE80211_IBSS_MLME_JOINED
455  */
456
457 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
458 {
459         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
460
461         mod_timer(&ifibss->timer,
462                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
463
464         ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
465
466         if (time_before(jiffies, ifibss->last_scan_completed +
467                        IEEE80211_IBSS_MERGE_INTERVAL))
468                 return;
469
470         if (ieee80211_sta_active_ibss(sdata))
471                 return;
472
473         if (ifibss->fixed_channel)
474                 return;
475
476         printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
477                "IBSS networks with same SSID (merge)\n", sdata->name);
478
479         ieee80211_request_internal_scan(sdata, ifibss->ssid, ifibss->ssid_len);
480 }
481
482 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
483 {
484         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
485         struct ieee80211_local *local = sdata->local;
486         struct ieee80211_supported_band *sband;
487         u8 bssid[ETH_ALEN];
488         u16 capability;
489         int i;
490
491         if (ifibss->fixed_bssid) {
492                 memcpy(bssid, ifibss->bssid, ETH_ALEN);
493         } else {
494                 /* Generate random, not broadcast, locally administered BSSID. Mix in
495                  * own MAC address to make sure that devices that do not have proper
496                  * random number generator get different BSSID. */
497                 get_random_bytes(bssid, ETH_ALEN);
498                 for (i = 0; i < ETH_ALEN; i++)
499                         bssid[i] ^= sdata->vif.addr[i];
500                 bssid[0] &= ~0x01;
501                 bssid[0] |= 0x02;
502         }
503
504         printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n",
505                sdata->name, bssid);
506
507         sband = local->hw.wiphy->bands[ifibss->channel->band];
508
509         capability = WLAN_CAPABILITY_IBSS;
510
511         if (ifibss->privacy)
512                 capability |= WLAN_CAPABILITY_PRIVACY;
513         else
514                 sdata->drop_unencrypted = 0;
515
516         __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
517                                   ifibss->channel, 3, /* first two are basic */
518                                   capability, 0);
519 }
520
521 /*
522  * This function is called with state == IEEE80211_IBSS_MLME_SEARCH
523  */
524
525 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
526 {
527         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
528         struct ieee80211_local *local = sdata->local;
529         struct cfg80211_bss *cbss;
530         struct ieee80211_channel *chan = NULL;
531         const u8 *bssid = NULL;
532         int active_ibss;
533         u16 capability;
534
535         active_ibss = ieee80211_sta_active_ibss(sdata);
536 #ifdef CONFIG_MAC80211_IBSS_DEBUG
537         printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n",
538                sdata->name, active_ibss);
539 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
540
541         if (active_ibss)
542                 return;
543
544         capability = WLAN_CAPABILITY_IBSS;
545         if (ifibss->privacy)
546                 capability |= WLAN_CAPABILITY_PRIVACY;
547         if (ifibss->fixed_bssid)
548                 bssid = ifibss->bssid;
549         if (ifibss->fixed_channel)
550                 chan = ifibss->channel;
551         if (!is_zero_ether_addr(ifibss->bssid))
552                 bssid = ifibss->bssid;
553         cbss = cfg80211_get_bss(local->hw.wiphy, chan, bssid,
554                                 ifibss->ssid, ifibss->ssid_len,
555                                 WLAN_CAPABILITY_IBSS | WLAN_CAPABILITY_PRIVACY,
556                                 capability);
557
558         if (cbss) {
559                 struct ieee80211_bss *bss;
560
561                 bss = (void *)cbss->priv;
562 #ifdef CONFIG_MAC80211_IBSS_DEBUG
563                 printk(KERN_DEBUG "   sta_find_ibss: selected %pM current "
564                        "%pM\n", cbss->bssid, ifibss->bssid);
565 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
566
567                 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM"
568                        " based on configured SSID\n",
569                        sdata->name, cbss->bssid);
570
571                 ieee80211_sta_join_ibss(sdata, bss);
572                 ieee80211_rx_bss_put(local, bss);
573                 return;
574         }
575
576 #ifdef CONFIG_MAC80211_IBSS_DEBUG
577         printk(KERN_DEBUG "   did not try to join ibss\n");
578 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
579
580         /* Selected IBSS not found in current scan results - try to scan */
581         if (time_after(jiffies, ifibss->last_scan_completed +
582                                         IEEE80211_SCAN_INTERVAL)) {
583                 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
584                        "join\n", sdata->name);
585
586                 ieee80211_request_internal_scan(sdata, ifibss->ssid,
587                                                 ifibss->ssid_len);
588         } else {
589                 int interval = IEEE80211_SCAN_INTERVAL;
590
591                 if (time_after(jiffies, ifibss->ibss_join_req +
592                                IEEE80211_IBSS_JOIN_TIMEOUT)) {
593                         if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
594                                 ieee80211_sta_create_ibss(sdata);
595                                 return;
596                         }
597                         printk(KERN_DEBUG "%s: IBSS not allowed on"
598                                " %d MHz\n", sdata->name,
599                                local->hw.conf.channel->center_freq);
600
601                         /* No IBSS found - decrease scan interval and continue
602                          * scanning. */
603                         interval = IEEE80211_SCAN_INTERVAL_SLOW;
604                 }
605
606                 mod_timer(&ifibss->timer,
607                           round_jiffies(jiffies + interval));
608         }
609 }
610
611 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
612                                         struct ieee80211_mgmt *mgmt,
613                                         size_t len)
614 {
615         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
616         struct ieee80211_local *local = sdata->local;
617         int tx_last_beacon;
618         struct sk_buff *skb;
619         struct ieee80211_mgmt *resp;
620         u8 *pos, *end;
621
622         if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
623             len < 24 + 2 || !ifibss->presp)
624                 return;
625
626         tx_last_beacon = drv_tx_last_beacon(local);
627
628 #ifdef CONFIG_MAC80211_IBSS_DEBUG
629         printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM"
630                " (tx_last_beacon=%d)\n",
631                sdata->name, mgmt->sa, mgmt->da,
632                mgmt->bssid, tx_last_beacon);
633 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
634
635         if (!tx_last_beacon)
636                 return;
637
638         if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 &&
639             memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0)
640                 return;
641
642         end = ((u8 *) mgmt) + len;
643         pos = mgmt->u.probe_req.variable;
644         if (pos[0] != WLAN_EID_SSID ||
645             pos + 2 + pos[1] > end) {
646 #ifdef CONFIG_MAC80211_IBSS_DEBUG
647                 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq "
648                        "from %pM\n",
649                        sdata->name, mgmt->sa);
650 #endif
651                 return;
652         }
653         if (pos[1] != 0 &&
654             (pos[1] != ifibss->ssid_len ||
655              memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
656                 /* Ignore ProbeReq for foreign SSID */
657                 return;
658         }
659
660         /* Reply with ProbeResp */
661         skb = skb_copy(ifibss->presp, GFP_KERNEL);
662         if (!skb)
663                 return;
664
665         resp = (struct ieee80211_mgmt *) skb->data;
666         memcpy(resp->da, mgmt->sa, ETH_ALEN);
667 #ifdef CONFIG_MAC80211_IBSS_DEBUG
668         printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n",
669                sdata->name, resp->da);
670 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
671         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
672         ieee80211_tx_skb(sdata, skb);
673 }
674
675 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
676                                          struct ieee80211_mgmt *mgmt,
677                                          size_t len,
678                                          struct ieee80211_rx_status *rx_status)
679 {
680         size_t baselen;
681         struct ieee802_11_elems elems;
682
683         if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN))
684                 return; /* ignore ProbeResp to foreign address */
685
686         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
687         if (baselen > len)
688                 return;
689
690         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
691                                 &elems);
692
693         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
694 }
695
696 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
697                                      struct ieee80211_mgmt *mgmt,
698                                      size_t len,
699                                      struct ieee80211_rx_status *rx_status)
700 {
701         size_t baselen;
702         struct ieee802_11_elems elems;
703
704         /* Process beacon from the current BSS */
705         baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
706         if (baselen > len)
707                 return;
708
709         ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
710
711         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
712 }
713
714 static void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
715                                           struct sk_buff *skb)
716 {
717         struct ieee80211_rx_status *rx_status;
718         struct ieee80211_mgmt *mgmt;
719         u16 fc;
720
721         rx_status = IEEE80211_SKB_RXCB(skb);
722         mgmt = (struct ieee80211_mgmt *) skb->data;
723         fc = le16_to_cpu(mgmt->frame_control);
724
725         switch (fc & IEEE80211_FCTL_STYPE) {
726         case IEEE80211_STYPE_PROBE_REQ:
727                 ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len);
728                 break;
729         case IEEE80211_STYPE_PROBE_RESP:
730                 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
731                                              rx_status);
732                 break;
733         case IEEE80211_STYPE_BEACON:
734                 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
735                                          rx_status);
736                 break;
737         case IEEE80211_STYPE_AUTH:
738                 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
739                 break;
740         }
741
742         kfree_skb(skb);
743 }
744
745 static void ieee80211_ibss_work(struct work_struct *work)
746 {
747         struct ieee80211_sub_if_data *sdata =
748                 container_of(work, struct ieee80211_sub_if_data, u.ibss.work);
749         struct ieee80211_local *local = sdata->local;
750         struct ieee80211_if_ibss *ifibss;
751         struct sk_buff *skb;
752
753         if (WARN_ON(local->suspended))
754                 return;
755
756         if (!ieee80211_sdata_running(sdata))
757                 return;
758
759         if (local->scanning)
760                 return;
761
762         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_ADHOC))
763                 return;
764         ifibss = &sdata->u.ibss;
765
766         while ((skb = skb_dequeue(&ifibss->skb_queue)))
767                 ieee80211_ibss_rx_queued_mgmt(sdata, skb);
768
769         if (!test_and_clear_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request))
770                 return;
771
772         switch (ifibss->state) {
773         case IEEE80211_IBSS_MLME_SEARCH:
774                 ieee80211_sta_find_ibss(sdata);
775                 break;
776         case IEEE80211_IBSS_MLME_JOINED:
777                 ieee80211_sta_merge_ibss(sdata);
778                 break;
779         default:
780                 WARN_ON(1);
781                 break;
782         }
783 }
784
785 static void ieee80211_ibss_timer(unsigned long data)
786 {
787         struct ieee80211_sub_if_data *sdata =
788                 (struct ieee80211_sub_if_data *) data;
789         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
790         struct ieee80211_local *local = sdata->local;
791
792         if (local->quiescing) {
793                 ifibss->timer_running = true;
794                 return;
795         }
796
797         set_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request);
798         ieee80211_queue_work(&local->hw, &ifibss->work);
799 }
800
801 #ifdef CONFIG_PM
802 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata)
803 {
804         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
805
806         cancel_work_sync(&ifibss->work);
807         if (del_timer_sync(&ifibss->timer))
808                 ifibss->timer_running = true;
809 }
810
811 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata)
812 {
813         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
814
815         if (ifibss->timer_running) {
816                 add_timer(&ifibss->timer);
817                 ifibss->timer_running = false;
818         }
819 }
820 #endif
821
822 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
823 {
824         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
825
826         INIT_WORK(&ifibss->work, ieee80211_ibss_work);
827         setup_timer(&ifibss->timer, ieee80211_ibss_timer,
828                     (unsigned long) sdata);
829         skb_queue_head_init(&ifibss->skb_queue);
830 }
831
832 /* scan finished notification */
833 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
834 {
835         struct ieee80211_sub_if_data *sdata;
836
837         mutex_lock(&local->iflist_mtx);
838         list_for_each_entry(sdata, &local->interfaces, list) {
839                 if (!ieee80211_sdata_running(sdata))
840                         continue;
841                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
842                         continue;
843                 if (!sdata->u.ibss.ssid_len)
844                         continue;
845                 sdata->u.ibss.last_scan_completed = jiffies;
846                 mod_timer(&sdata->u.ibss.timer, 0);
847         }
848         mutex_unlock(&local->iflist_mtx);
849 }
850
851 ieee80211_rx_result
852 ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
853 {
854         struct ieee80211_local *local = sdata->local;
855         struct ieee80211_mgmt *mgmt;
856         u16 fc;
857
858         if (skb->len < 24)
859                 return RX_DROP_MONITOR;
860
861         mgmt = (struct ieee80211_mgmt *) skb->data;
862         fc = le16_to_cpu(mgmt->frame_control);
863
864         switch (fc & IEEE80211_FCTL_STYPE) {
865         case IEEE80211_STYPE_PROBE_RESP:
866         case IEEE80211_STYPE_BEACON:
867         case IEEE80211_STYPE_PROBE_REQ:
868         case IEEE80211_STYPE_AUTH:
869                 skb_queue_tail(&sdata->u.ibss.skb_queue, skb);
870                 ieee80211_queue_work(&local->hw, &sdata->u.ibss.work);
871                 return RX_QUEUED;
872         }
873
874         return RX_DROP_MONITOR;
875 }
876
877 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
878                         struct cfg80211_ibss_params *params)
879 {
880         struct sk_buff *skb;
881
882         if (params->bssid) {
883                 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
884                 sdata->u.ibss.fixed_bssid = true;
885         } else
886                 sdata->u.ibss.fixed_bssid = false;
887
888         sdata->u.ibss.privacy = params->privacy;
889
890         sdata->vif.bss_conf.beacon_int = params->beacon_interval;
891
892         sdata->u.ibss.channel = params->channel;
893         sdata->u.ibss.fixed_channel = params->channel_fixed;
894
895         if (params->ie) {
896                 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
897                                            GFP_KERNEL);
898                 if (sdata->u.ibss.ie)
899                         sdata->u.ibss.ie_len = params->ie_len;
900         }
901
902         skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
903                             36 /* bitrates */ +
904                             34 /* SSID */ +
905                             3  /* DS params */ +
906                             4  /* IBSS params */ +
907                             params->ie_len);
908         if (!skb)
909                 return -ENOMEM;
910
911         sdata->u.ibss.skb = skb;
912         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
913         sdata->u.ibss.ibss_join_req = jiffies;
914
915         memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);
916
917         /*
918          * The ssid_len setting below is used to see whether
919          * we are active, and we need all other settings
920          * before that may get visible.
921          */
922         mb();
923
924         sdata->u.ibss.ssid_len = params->ssid_len;
925
926         ieee80211_recalc_idle(sdata->local);
927
928         set_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
929         ieee80211_queue_work(&sdata->local->hw, &sdata->u.ibss.work);
930
931         return 0;
932 }
933
934 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
935 {
936         struct sk_buff *skb;
937
938         del_timer_sync(&sdata->u.ibss.timer);
939         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
940         cancel_work_sync(&sdata->u.ibss.work);
941         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
942
943         sta_info_flush(sdata->local, sdata);
944
945         /* remove beacon */
946         kfree(sdata->u.ibss.ie);
947         skb = sdata->u.ibss.presp;
948         rcu_assign_pointer(sdata->u.ibss.presp, NULL);
949         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
950         synchronize_rcu();
951         kfree_skb(skb);
952
953         skb_queue_purge(&sdata->u.ibss.skb_queue);
954         memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
955         sdata->u.ibss.ssid_len = 0;
956
957         ieee80211_recalc_idle(sdata->local);
958
959         return 0;
960 }