ef6c6b2401d1d25d0bb2be1f268231bd880734d6
[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 ieee80211_supported_band *sband;
191         u32 basic_rates;
192         int i, j;
193         u16 beacon_int = bss->cbss.beacon_interval;
194
195         if (beacon_int < 10)
196                 beacon_int = 10;
197
198         sband = sdata->local->hw.wiphy->bands[bss->cbss.channel->band];
199
200         basic_rates = 0;
201
202         for (i = 0; i < bss->supp_rates_len; i++) {
203                 int rate = (bss->supp_rates[i] & 0x7f) * 5;
204                 bool is_basic = !!(bss->supp_rates[i] & 0x80);
205
206                 for (j = 0; j < sband->n_bitrates; j++) {
207                         if (sband->bitrates[j].bitrate == rate) {
208                                 if (is_basic)
209                                         basic_rates |= BIT(j);
210                                 break;
211                         }
212                 }
213         }
214
215         __ieee80211_sta_join_ibss(sdata, bss->cbss.bssid,
216                                   beacon_int,
217                                   bss->cbss.channel,
218                                   basic_rates,
219                                   bss->cbss.capability,
220                                   bss->cbss.tsf);
221 }
222
223 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
224                                   struct ieee80211_mgmt *mgmt,
225                                   size_t len,
226                                   struct ieee80211_rx_status *rx_status,
227                                   struct ieee802_11_elems *elems,
228                                   bool beacon)
229 {
230         struct ieee80211_local *local = sdata->local;
231         int freq;
232         struct ieee80211_bss *bss;
233         struct sta_info *sta;
234         struct ieee80211_channel *channel;
235         u64 beacon_timestamp, rx_timestamp;
236         u32 supp_rates = 0;
237         enum ieee80211_band band = rx_status->band;
238
239         if (elems->ds_params && elems->ds_params_len == 1)
240                 freq = ieee80211_channel_to_frequency(elems->ds_params[0]);
241         else
242                 freq = rx_status->freq;
243
244         channel = ieee80211_get_channel(local->hw.wiphy, freq);
245
246         if (!channel || channel->flags & IEEE80211_CHAN_DISABLED)
247                 return;
248
249         if (sdata->vif.type == NL80211_IFTYPE_ADHOC && elems->supp_rates &&
250             memcmp(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0) {
251                 supp_rates = ieee80211_sta_get_rates(local, elems, band);
252
253                 rcu_read_lock();
254
255                 sta = sta_info_get(sdata, mgmt->sa);
256                 if (sta) {
257                         u32 prev_rates;
258
259                         prev_rates = sta->sta.supp_rates[band];
260                         /* make sure mandatory rates are always added */
261                         sta->sta.supp_rates[band] = supp_rates |
262                                 ieee80211_mandatory_rates(local, band);
263
264 #ifdef CONFIG_MAC80211_IBSS_DEBUG
265                         if (sta->sta.supp_rates[band] != prev_rates)
266                                 printk(KERN_DEBUG "%s: updated supp_rates set "
267                                     "for %pM based on beacon info (0x%llx | "
268                                     "0x%llx -> 0x%llx)\n",
269                                     sdata->name,
270                                     sta->sta.addr,
271                                     (unsigned long long) prev_rates,
272                                     (unsigned long long) supp_rates,
273                                     (unsigned long long) sta->sta.supp_rates[band]);
274 #endif
275                 } else
276                         ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates);
277
278                 rcu_read_unlock();
279         }
280
281         bss = ieee80211_bss_info_update(local, rx_status, mgmt, len, elems,
282                                         channel, beacon);
283         if (!bss)
284                 return;
285
286         /* was just updated in ieee80211_bss_info_update */
287         beacon_timestamp = bss->cbss.tsf;
288
289         /* check if we need to merge IBSS */
290
291         /* merge only on beacons (???) */
292         if (!beacon)
293                 goto put_bss;
294
295         /* we use a fixed BSSID */
296         if (sdata->u.ibss.bssid)
297                 goto put_bss;
298
299         /* not an IBSS */
300         if (!(bss->cbss.capability & WLAN_CAPABILITY_IBSS))
301                 goto put_bss;
302
303         /* different channel */
304         if (bss->cbss.channel != local->oper_channel)
305                 goto put_bss;
306
307         /* different SSID */
308         if (elems->ssid_len != sdata->u.ibss.ssid_len ||
309             memcmp(elems->ssid, sdata->u.ibss.ssid,
310                                 sdata->u.ibss.ssid_len))
311                 goto put_bss;
312
313         /* same BSSID */
314         if (memcmp(bss->cbss.bssid, sdata->u.ibss.bssid, ETH_ALEN) == 0)
315                 goto put_bss;
316
317         if (rx_status->flag & RX_FLAG_TSFT) {
318                 /*
319                  * For correct IBSS merging we need mactime; since mactime is
320                  * defined as the time the first data symbol of the frame hits
321                  * the PHY, and the timestamp of the beacon is defined as "the
322                  * time that the data symbol containing the first bit of the
323                  * timestamp is transmitted to the PHY plus the transmitting
324                  * STA's delays through its local PHY from the MAC-PHY
325                  * interface to its interface with the WM" (802.11 11.1.2)
326                  * - equals the time this bit arrives at the receiver - we have
327                  * to take into account the offset between the two.
328                  *
329                  * E.g. at 1 MBit that means mactime is 192 usec earlier
330                  * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
331                  */
332                 int rate;
333
334                 if (rx_status->flag & RX_FLAG_HT)
335                         rate = 65; /* TODO: HT rates */
336                 else
337                         rate = local->hw.wiphy->bands[band]->
338                                 bitrates[rx_status->rate_idx].bitrate;
339
340                 rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
341         } else {
342                 /*
343                  * second best option: get current TSF
344                  * (will return -1 if not supported)
345                  */
346                 rx_timestamp = drv_get_tsf(local);
347         }
348
349 #ifdef CONFIG_MAC80211_IBSS_DEBUG
350         printk(KERN_DEBUG "RX beacon SA=%pM BSSID="
351                "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n",
352                mgmt->sa, mgmt->bssid,
353                (unsigned long long)rx_timestamp,
354                (unsigned long long)beacon_timestamp,
355                (unsigned long long)(rx_timestamp - beacon_timestamp),
356                jiffies);
357 #endif
358
359         /* give slow hardware some time to do the TSF sync */
360         if (rx_timestamp < IEEE80211_IBSS_MERGE_DELAY)
361                 goto put_bss;
362
363         if (beacon_timestamp > rx_timestamp) {
364 #ifdef CONFIG_MAC80211_IBSS_DEBUG
365                 printk(KERN_DEBUG "%s: beacon TSF higher than "
366                        "local TSF - IBSS merge with BSSID %pM\n",
367                        sdata->name, mgmt->bssid);
368 #endif
369                 ieee80211_sta_join_ibss(sdata, bss);
370                 ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates);
371         }
372
373  put_bss:
374         ieee80211_rx_bss_put(local, bss);
375 }
376
377 /*
378  * Add a new IBSS station, will also be called by the RX code when,
379  * in IBSS mode, receiving a frame from a yet-unknown station, hence
380  * must be callable in atomic context.
381  */
382 struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
383                                         u8 *bssid,u8 *addr, u32 supp_rates)
384 {
385         struct ieee80211_local *local = sdata->local;
386         struct sta_info *sta;
387         int band = local->hw.conf.channel->band;
388
389         /*
390          * XXX: Consider removing the least recently used entry and
391          *      allow new one to be added.
392          */
393         if (local->num_sta >= IEEE80211_IBSS_MAX_STA_ENTRIES) {
394                 if (net_ratelimit())
395                         printk(KERN_DEBUG "%s: No room for a new IBSS STA entry %pM\n",
396                                sdata->name, addr);
397                 return NULL;
398         }
399
400         if (compare_ether_addr(bssid, sdata->u.ibss.bssid))
401                 return NULL;
402
403 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
404         printk(KERN_DEBUG "%s: Adding new IBSS station %pM (dev=%s)\n",
405                wiphy_name(local->hw.wiphy), addr, sdata->name);
406 #endif
407
408         sta = sta_info_alloc(sdata, addr, GFP_ATOMIC);
409         if (!sta)
410                 return NULL;
411
412         set_sta_flags(sta, WLAN_STA_AUTHORIZED);
413
414         /* make sure mandatory rates are always added */
415         sta->sta.supp_rates[band] = supp_rates |
416                         ieee80211_mandatory_rates(local, band);
417
418         rate_control_rate_init(sta);
419
420         if (sta_info_insert(sta))
421                 return NULL;
422
423         return sta;
424 }
425
426 static int ieee80211_sta_active_ibss(struct ieee80211_sub_if_data *sdata)
427 {
428         struct ieee80211_local *local = sdata->local;
429         int active = 0;
430         struct sta_info *sta;
431
432         rcu_read_lock();
433
434         list_for_each_entry_rcu(sta, &local->sta_list, list) {
435                 if (sta->sdata == sdata &&
436                     time_after(sta->last_rx + IEEE80211_IBSS_MERGE_INTERVAL,
437                                jiffies)) {
438                         active++;
439                         break;
440                 }
441         }
442
443         rcu_read_unlock();
444
445         return active;
446 }
447
448
449 static void ieee80211_sta_merge_ibss(struct ieee80211_sub_if_data *sdata)
450 {
451         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
452
453         mod_timer(&ifibss->timer,
454                   round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
455
456         ieee80211_sta_expire(sdata, IEEE80211_IBSS_INACTIVITY_LIMIT);
457
458         if (time_before(jiffies, ifibss->last_scan_completed +
459                        IEEE80211_IBSS_MERGE_INTERVAL))
460                 return;
461
462         if (ieee80211_sta_active_ibss(sdata))
463                 return;
464
465         if (ifibss->fixed_channel)
466                 return;
467
468         printk(KERN_DEBUG "%s: No active IBSS STAs - trying to scan for other "
469                "IBSS networks with same SSID (merge)\n", sdata->name);
470
471         ieee80211_request_internal_scan(sdata, ifibss->ssid, ifibss->ssid_len);
472 }
473
474 static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
475 {
476         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
477         struct ieee80211_local *local = sdata->local;
478         struct ieee80211_supported_band *sband;
479         u8 bssid[ETH_ALEN];
480         u16 capability;
481         int i;
482
483         if (ifibss->fixed_bssid) {
484                 memcpy(bssid, ifibss->bssid, ETH_ALEN);
485         } else {
486                 /* Generate random, not broadcast, locally administered BSSID. Mix in
487                  * own MAC address to make sure that devices that do not have proper
488                  * random number generator get different BSSID. */
489                 get_random_bytes(bssid, ETH_ALEN);
490                 for (i = 0; i < ETH_ALEN; i++)
491                         bssid[i] ^= sdata->vif.addr[i];
492                 bssid[0] &= ~0x01;
493                 bssid[0] |= 0x02;
494         }
495
496         printk(KERN_DEBUG "%s: Creating new IBSS network, BSSID %pM\n",
497                sdata->name, bssid);
498
499         sband = local->hw.wiphy->bands[ifibss->channel->band];
500
501         capability = WLAN_CAPABILITY_IBSS;
502
503         if (ifibss->privacy)
504                 capability |= WLAN_CAPABILITY_PRIVACY;
505         else
506                 sdata->drop_unencrypted = 0;
507
508         __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
509                                   ifibss->channel, 3, /* first two are basic */
510                                   capability, 0);
511 }
512
513 static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
514 {
515         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
516         struct ieee80211_local *local = sdata->local;
517         struct ieee80211_bss *bss;
518         struct ieee80211_channel *chan = NULL;
519         const u8 *bssid = NULL;
520         int active_ibss;
521         u16 capability;
522
523         active_ibss = ieee80211_sta_active_ibss(sdata);
524 #ifdef CONFIG_MAC80211_IBSS_DEBUG
525         printk(KERN_DEBUG "%s: sta_find_ibss (active_ibss=%d)\n",
526                sdata->name, active_ibss);
527 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
528
529         if (active_ibss)
530                 return;
531
532         capability = WLAN_CAPABILITY_IBSS;
533         if (ifibss->privacy)
534                 capability |= WLAN_CAPABILITY_PRIVACY;
535         if (ifibss->fixed_bssid)
536                 bssid = ifibss->bssid;
537         if (ifibss->fixed_channel)
538                 chan = ifibss->channel;
539         if (!is_zero_ether_addr(ifibss->bssid))
540                 bssid = ifibss->bssid;
541         bss = (void *)cfg80211_get_bss(local->hw.wiphy, chan, bssid,
542                                        ifibss->ssid, ifibss->ssid_len,
543                                        WLAN_CAPABILITY_IBSS |
544                                        WLAN_CAPABILITY_PRIVACY,
545                                        capability);
546
547         if (bss) {
548 #ifdef CONFIG_MAC80211_IBSS_DEBUG
549                 printk(KERN_DEBUG "   sta_find_ibss: selected %pM current "
550                        "%pM\n", bss->cbss.bssid, ifibss->bssid);
551 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
552
553                 printk(KERN_DEBUG "%s: Selected IBSS BSSID %pM"
554                        " based on configured SSID\n",
555                        sdata->name, bss->cbss.bssid);
556
557                 ieee80211_sta_join_ibss(sdata, bss);
558                 ieee80211_rx_bss_put(local, bss);
559                 return;
560         }
561
562 #ifdef CONFIG_MAC80211_IBSS_DEBUG
563         printk(KERN_DEBUG "   did not try to join ibss\n");
564 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
565
566         /* Selected IBSS not found in current scan results - try to scan */
567         if (ifibss->state == IEEE80211_IBSS_MLME_JOINED &&
568             !ieee80211_sta_active_ibss(sdata)) {
569                 mod_timer(&ifibss->timer,
570                           round_jiffies(jiffies + IEEE80211_IBSS_MERGE_INTERVAL));
571         } else if (time_after(jiffies, ifibss->last_scan_completed +
572                                         IEEE80211_SCAN_INTERVAL)) {
573                 printk(KERN_DEBUG "%s: Trigger new scan to find an IBSS to "
574                        "join\n", sdata->name);
575
576                 ieee80211_request_internal_scan(sdata, ifibss->ssid,
577                                                 ifibss->ssid_len);
578         } else if (ifibss->state != IEEE80211_IBSS_MLME_JOINED) {
579                 int interval = IEEE80211_SCAN_INTERVAL;
580
581                 if (time_after(jiffies, ifibss->ibss_join_req +
582                                IEEE80211_IBSS_JOIN_TIMEOUT)) {
583                         if (!(local->oper_channel->flags & IEEE80211_CHAN_NO_IBSS)) {
584                                 ieee80211_sta_create_ibss(sdata);
585                                 return;
586                         }
587                         printk(KERN_DEBUG "%s: IBSS not allowed on"
588                                " %d MHz\n", sdata->name,
589                                local->hw.conf.channel->center_freq);
590
591                         /* No IBSS found - decrease scan interval and continue
592                          * scanning. */
593                         interval = IEEE80211_SCAN_INTERVAL_SLOW;
594                 }
595
596                 ifibss->state = IEEE80211_IBSS_MLME_SEARCH;
597                 mod_timer(&ifibss->timer,
598                           round_jiffies(jiffies + interval));
599         }
600 }
601
602 static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata,
603                                         struct ieee80211_mgmt *mgmt,
604                                         size_t len)
605 {
606         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
607         struct ieee80211_local *local = sdata->local;
608         int tx_last_beacon;
609         struct sk_buff *skb;
610         struct ieee80211_mgmt *resp;
611         u8 *pos, *end;
612
613         if (ifibss->state != IEEE80211_IBSS_MLME_JOINED ||
614             len < 24 + 2 || !ifibss->presp)
615                 return;
616
617         tx_last_beacon = drv_tx_last_beacon(local);
618
619 #ifdef CONFIG_MAC80211_IBSS_DEBUG
620         printk(KERN_DEBUG "%s: RX ProbeReq SA=%pM DA=%pM BSSID=%pM"
621                " (tx_last_beacon=%d)\n",
622                sdata->name, mgmt->sa, mgmt->da,
623                mgmt->bssid, tx_last_beacon);
624 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
625
626         if (!tx_last_beacon)
627                 return;
628
629         if (memcmp(mgmt->bssid, ifibss->bssid, ETH_ALEN) != 0 &&
630             memcmp(mgmt->bssid, "\xff\xff\xff\xff\xff\xff", ETH_ALEN) != 0)
631                 return;
632
633         end = ((u8 *) mgmt) + len;
634         pos = mgmt->u.probe_req.variable;
635         if (pos[0] != WLAN_EID_SSID ||
636             pos + 2 + pos[1] > end) {
637 #ifdef CONFIG_MAC80211_IBSS_DEBUG
638                 printk(KERN_DEBUG "%s: Invalid SSID IE in ProbeReq "
639                        "from %pM\n",
640                        sdata->name, mgmt->sa);
641 #endif
642                 return;
643         }
644         if (pos[1] != 0 &&
645             (pos[1] != ifibss->ssid_len ||
646              !memcmp(pos + 2, ifibss->ssid, ifibss->ssid_len))) {
647                 /* Ignore ProbeReq for foreign SSID */
648                 return;
649         }
650
651         /* Reply with ProbeResp */
652         skb = skb_copy(ifibss->presp, GFP_KERNEL);
653         if (!skb)
654                 return;
655
656         resp = (struct ieee80211_mgmt *) skb->data;
657         memcpy(resp->da, mgmt->sa, ETH_ALEN);
658 #ifdef CONFIG_MAC80211_IBSS_DEBUG
659         printk(KERN_DEBUG "%s: Sending ProbeResp to %pM\n",
660                sdata->name, resp->da);
661 #endif /* CONFIG_MAC80211_IBSS_DEBUG */
662         IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT;
663         ieee80211_tx_skb(sdata, skb);
664 }
665
666 static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata,
667                                          struct ieee80211_mgmt *mgmt,
668                                          size_t len,
669                                          struct ieee80211_rx_status *rx_status)
670 {
671         size_t baselen;
672         struct ieee802_11_elems elems;
673
674         if (memcmp(mgmt->da, sdata->vif.addr, ETH_ALEN))
675                 return; /* ignore ProbeResp to foreign address */
676
677         baselen = (u8 *) mgmt->u.probe_resp.variable - (u8 *) mgmt;
678         if (baselen > len)
679                 return;
680
681         ieee802_11_parse_elems(mgmt->u.probe_resp.variable, len - baselen,
682                                 &elems);
683
684         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, false);
685 }
686
687 static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
688                                      struct ieee80211_mgmt *mgmt,
689                                      size_t len,
690                                      struct ieee80211_rx_status *rx_status)
691 {
692         size_t baselen;
693         struct ieee802_11_elems elems;
694
695         /* Process beacon from the current BSS */
696         baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
697         if (baselen > len)
698                 return;
699
700         ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems);
701
702         ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true);
703 }
704
705 static void ieee80211_ibss_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
706                                           struct sk_buff *skb)
707 {
708         struct ieee80211_rx_status *rx_status;
709         struct ieee80211_mgmt *mgmt;
710         u16 fc;
711
712         rx_status = IEEE80211_SKB_RXCB(skb);
713         mgmt = (struct ieee80211_mgmt *) skb->data;
714         fc = le16_to_cpu(mgmt->frame_control);
715
716         switch (fc & IEEE80211_FCTL_STYPE) {
717         case IEEE80211_STYPE_PROBE_REQ:
718                 ieee80211_rx_mgmt_probe_req(sdata, mgmt, skb->len);
719                 break;
720         case IEEE80211_STYPE_PROBE_RESP:
721                 ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len,
722                                              rx_status);
723                 break;
724         case IEEE80211_STYPE_BEACON:
725                 ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len,
726                                          rx_status);
727                 break;
728         case IEEE80211_STYPE_AUTH:
729                 ieee80211_rx_mgmt_auth_ibss(sdata, mgmt, skb->len);
730                 break;
731         }
732
733         kfree_skb(skb);
734 }
735
736 static void ieee80211_ibss_work(struct work_struct *work)
737 {
738         struct ieee80211_sub_if_data *sdata =
739                 container_of(work, struct ieee80211_sub_if_data, u.ibss.work);
740         struct ieee80211_local *local = sdata->local;
741         struct ieee80211_if_ibss *ifibss;
742         struct sk_buff *skb;
743
744         if (WARN_ON(local->suspended))
745                 return;
746
747         if (!netif_running(sdata->dev))
748                 return;
749
750         if (local->scanning)
751                 return;
752
753         if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_ADHOC))
754                 return;
755         ifibss = &sdata->u.ibss;
756
757         while ((skb = skb_dequeue(&ifibss->skb_queue)))
758                 ieee80211_ibss_rx_queued_mgmt(sdata, skb);
759
760         if (!test_and_clear_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request))
761                 return;
762
763         switch (ifibss->state) {
764         case IEEE80211_IBSS_MLME_SEARCH:
765                 ieee80211_sta_find_ibss(sdata);
766                 break;
767         case IEEE80211_IBSS_MLME_JOINED:
768                 ieee80211_sta_merge_ibss(sdata);
769                 break;
770         default:
771                 WARN_ON(1);
772                 break;
773         }
774 }
775
776 static void ieee80211_ibss_timer(unsigned long data)
777 {
778         struct ieee80211_sub_if_data *sdata =
779                 (struct ieee80211_sub_if_data *) data;
780         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
781         struct ieee80211_local *local = sdata->local;
782
783         if (local->quiescing) {
784                 ifibss->timer_running = true;
785                 return;
786         }
787
788         set_bit(IEEE80211_IBSS_REQ_RUN, &ifibss->request);
789         ieee80211_queue_work(&local->hw, &ifibss->work);
790 }
791
792 #ifdef CONFIG_PM
793 void ieee80211_ibss_quiesce(struct ieee80211_sub_if_data *sdata)
794 {
795         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
796
797         cancel_work_sync(&ifibss->work);
798         if (del_timer_sync(&ifibss->timer))
799                 ifibss->timer_running = true;
800 }
801
802 void ieee80211_ibss_restart(struct ieee80211_sub_if_data *sdata)
803 {
804         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
805
806         if (ifibss->timer_running) {
807                 add_timer(&ifibss->timer);
808                 ifibss->timer_running = false;
809         }
810 }
811 #endif
812
813 void ieee80211_ibss_setup_sdata(struct ieee80211_sub_if_data *sdata)
814 {
815         struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
816
817         INIT_WORK(&ifibss->work, ieee80211_ibss_work);
818         setup_timer(&ifibss->timer, ieee80211_ibss_timer,
819                     (unsigned long) sdata);
820         skb_queue_head_init(&ifibss->skb_queue);
821 }
822
823 /* scan finished notification */
824 void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
825 {
826         struct ieee80211_sub_if_data *sdata;
827
828         mutex_lock(&local->iflist_mtx);
829         list_for_each_entry(sdata, &local->interfaces, list) {
830                 if (!netif_running(sdata->dev))
831                         continue;
832                 if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
833                         continue;
834                 if (!sdata->u.ibss.ssid_len)
835                         continue;
836                 sdata->u.ibss.last_scan_completed = jiffies;
837                 mod_timer(&sdata->u.ibss.timer, 0);
838         }
839         mutex_unlock(&local->iflist_mtx);
840 }
841
842 ieee80211_rx_result
843 ieee80211_ibss_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
844 {
845         struct ieee80211_local *local = sdata->local;
846         struct ieee80211_mgmt *mgmt;
847         u16 fc;
848
849         if (skb->len < 24)
850                 return RX_DROP_MONITOR;
851
852         mgmt = (struct ieee80211_mgmt *) skb->data;
853         fc = le16_to_cpu(mgmt->frame_control);
854
855         switch (fc & IEEE80211_FCTL_STYPE) {
856         case IEEE80211_STYPE_PROBE_RESP:
857         case IEEE80211_STYPE_BEACON:
858         case IEEE80211_STYPE_PROBE_REQ:
859         case IEEE80211_STYPE_AUTH:
860                 skb_queue_tail(&sdata->u.ibss.skb_queue, skb);
861                 ieee80211_queue_work(&local->hw, &sdata->u.ibss.work);
862                 return RX_QUEUED;
863         }
864
865         return RX_DROP_MONITOR;
866 }
867
868 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
869                         struct cfg80211_ibss_params *params)
870 {
871         struct sk_buff *skb;
872
873         if (params->bssid) {
874                 memcpy(sdata->u.ibss.bssid, params->bssid, ETH_ALEN);
875                 sdata->u.ibss.fixed_bssid = true;
876         } else
877                 sdata->u.ibss.fixed_bssid = false;
878
879         sdata->u.ibss.privacy = params->privacy;
880
881         sdata->vif.bss_conf.beacon_int = params->beacon_interval;
882
883         sdata->u.ibss.channel = params->channel;
884         sdata->u.ibss.fixed_channel = params->channel_fixed;
885
886         if (params->ie) {
887                 sdata->u.ibss.ie = kmemdup(params->ie, params->ie_len,
888                                            GFP_KERNEL);
889                 if (sdata->u.ibss.ie)
890                         sdata->u.ibss.ie_len = params->ie_len;
891         }
892
893         skb = dev_alloc_skb(sdata->local->hw.extra_tx_headroom +
894                             36 /* bitrates */ +
895                             34 /* SSID */ +
896                             3  /* DS params */ +
897                             4  /* IBSS params */ +
898                             params->ie_len);
899         if (!skb)
900                 return -ENOMEM;
901
902         sdata->u.ibss.skb = skb;
903         sdata->u.ibss.state = IEEE80211_IBSS_MLME_SEARCH;
904         sdata->u.ibss.ibss_join_req = jiffies;
905
906         memcpy(sdata->u.ibss.ssid, params->ssid, IEEE80211_MAX_SSID_LEN);
907
908         /*
909          * The ssid_len setting below is used to see whether
910          * we are active, and we need all other settings
911          * before that may get visible.
912          */
913         mb();
914
915         sdata->u.ibss.ssid_len = params->ssid_len;
916
917         ieee80211_recalc_idle(sdata->local);
918
919         set_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
920         ieee80211_queue_work(&sdata->local->hw, &sdata->u.ibss.work);
921
922         return 0;
923 }
924
925 int ieee80211_ibss_leave(struct ieee80211_sub_if_data *sdata)
926 {
927         struct sk_buff *skb;
928
929         del_timer_sync(&sdata->u.ibss.timer);
930         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
931         cancel_work_sync(&sdata->u.ibss.work);
932         clear_bit(IEEE80211_IBSS_REQ_RUN, &sdata->u.ibss.request);
933
934         sta_info_flush(sdata->local, sdata);
935
936         /* remove beacon */
937         kfree(sdata->u.ibss.ie);
938         skb = sdata->u.ibss.presp;
939         rcu_assign_pointer(sdata->u.ibss.presp, NULL);
940         ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
941         synchronize_rcu();
942         kfree_skb(skb);
943
944         skb_queue_purge(&sdata->u.ibss.skb_queue);
945         memset(sdata->u.ibss.bssid, 0, ETH_ALEN);
946         sdata->u.ibss.ssid_len = 0;
947
948         ieee80211_recalc_idle(sdata->local);
949
950         return 0;
951 }